LX200 Astrophotography --Page 1

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Subject: Is the LX200 Good for Astrophotography?    Top

From: Michael Hart

I felt the following private post to me may reflect a number of potential and current LX200 owners that may be discouraged at trying astrophotography.

The LX200 is quite able to handle long exposures without modification. Arguably, the LX200 has the best price/performance ratio of any scope and mount available today. Like many mass produced products, a few adjustments will improve results further. For some of us (probably a small minority) LX200 owners, part of the challenge is getting results that compare to mounts and scopes that are much more expensive.

A few of us tweak and fiddle with our scopes. This should not be construed to mean constant tweaking and fiddling is needed. For example, MAPUG members are a very small minority of LX200 owners. Those that are in MAPUG that tinker with the LX200 are still a smaller group- probably around 10-20 individuals out of many thousands of LX200 owners.

Some of us on MAPUG are pushing the LX200 design to the limits and more. Here, a few mods enable an inexpensive mount (a relative term) to produce results of a much more expensive setup. In my case, I wanted to piggy-back an 8" f/2.5 camera lens on my 12". The 12" has the same drive motors and gears as the much lighter 8". I also wanted to improve long exposure tricolor CCD imaging from what I already have produced on my current scope with only minor maintenance. By improve, I mean produce results to enable 90-100X enlargements of high S/N (signal to noise) ratio CCD images. This is of personal interest to me and quite possibly only me.

An example of what the LX200 can do in it's existing form is on Doc G's website under CCD Imagers and Accessories, Color Imaging Methods with the CCD Imager. Doc G's web site contains much detail about the LX200.

If your new to imaging with a telescope whether it be emulsion or CCD (I do both), I believe the biggest hurtle is gaining experience and NOT the equipment. In fact, I recommend those starting in imaging start off with a plain camera, off-axis guider and an illuminated reticle guiding eyepiece. Work on perfecting your techniques whenever possible and avoid getting caught up in buying accessories you will later find you don't need. Accessories will not substitute for experience. Your acquired experience will serve you well later as to what accessory is really needed for the desired results. Those with the financial means to purchase whatever they want may have a steeper learning curve than others because it is quite easy for them to buy too much, too soon. Don't let this happen to you.


Subject: Can the LX200 Deliver Precision Tracking for Imaging?    Top

From: Doc G, Date: June 2004

Oh yes, OAGs (off-axis guiders) work. BUT, the guide star in an OAG is at the very edge of the field. Thus rotation will be about the guide star and the stars on the opposite edge of the field will rotate the most. If the guide star is on the axis of the field, the edge stars move half as much or less. All of these schemes have some problems of course. The very best way to image is to have a very well aligned polar mount. I just came back from a week at New Mexico Skies where I used a Paramount ME that was very well aligned. You could do 5 minute exposures at 4000 mm and get pin point stars with no guiding at all. The Paramount ME, by Bisque, is the finest mount I have ever used by a great deal.

That is not to say that you cannot get fair results with a Meade fork. The LX200 12" in the Doc G observatory at the Madison Astronomical Society dark site will give pinpoint stars without guiding when used with a Takahashie 106 mounted piggy back and exposures are limited to 5 minutes. But I have worked on that scope for years and it is an exceptional example of a Meade fork mount which is well tuned and well aligned.

In general, with the Meade fork mount, if you get under 10 arc seconds error (with a good PEC) over one turn of the worm (8 minutes) you are very well tuned. I did have a 10" LX200 at one time which gave only 5 arc seconds offer 8 minutes. That too took very much tuning, tweaking and talking to the scope. (G)

For imaging with a Meade fork, I suggest very precise polar alignment, tuning the mount by cleaning the RA gears and lubricating properly, and doing a very careful PEC. Almost no dec action should take place for the exposure period. A highly precise polar alignment will allow for that to happen. You must align with the same total load of equipment as you use for imaging to within a Kg or so. Attention to all of these mechanical factors will give you a fairly good imaging platform. Patience and care are required to get these results. Fortunately the mapug archives are loaded with good information for getting the Meade fork mounts to work fairly well. I have preached long enough about the mechanics of the Meade forks. With a lot of TLC they can be used for imaging, but it takes a ton of TLC.


Subject: Can the LX200 Mirror Mount Allow Precision Tracking for Imaging?

From: Doc G,. Date: Oct 2004

Note on recent experience with primary mirror mounts in LX scopes.

I have recently had a good look at and spent some time tuning up a 16" LX 200 classic. (and several 12" scopes) I am assuming that my experience with this scope reflects the design problems with all scopes of this type. I was well impressed with the strength and fit of the mirror holder on the central tube and thus wondered where the mirror shift in this scope could be coming from.

I fear that the mirror shift is coming from the basic flexibility of the central tube itself. This means that no amount of clamping of the mirror carrier to the central tube will ever totally reduce mirror shift to zero. The entire weight of the mirror and tube assembly is held at the base end of the tube. There is a strong connection between the central tube and the back plate of the scope, but it is not perfectly rigid. I do not think you will ever be able to clamp a movable mirror in this arrangement perfectly enough to eliminate all mirror shift.

The only way to clamp the mirror in place it to mount it in a holder that is a part of the back plate of the scope. This would of course require a total redesign of the primary mirror holder. In fact, the mirror is so heavy and so poorly held by a light weight spider assembly in this design that is simply not desirable for either holding the mirror fixed or for holding it without some distortion of the mirror itself. It is time to face the fact that a scope with a movable primary mirror is not a high precision design. This design is simply not used in professional telescopes nor is it even used in relatively inexpensive Newtonians and the like.

Another factor is the stability of the secondary. The mounting of the secondary on the corrector is flimsy at best. The secondary shifts with scope position. That is a fact which also contributes to image shift with position. I am convinced, after this study of the 16" scope, that the design of the instrument is flawed for precision optical results.

Still another flaw is the design of the focus mechanism. There is a simply arm that pushes or pulls on one side of the primary mirror mounting spider. This is an incredibly weak design and a poor way to move the primary mirror. It would require a completely redesigned focusing means to fix this problem.

As I say, it is time to stop fighting the basic design flaws and use imaging techniques that get around them. These would include: refocusing and re-collimating for each region of the sky being imaged; keeping exposures short enough so that the scope does not move through very large arcs; re-focusing for even small temperature changes. These techniques may overcome some of the design limitations. Then of course there are the problems with the mount that also need to be taken into account. It is tough to image with these scopes for good reason. They are designed for viewing.


Subject: LX200 & Beginning Astrophotography Questions     Top

From: Robin Casady <rcasadya_tscruznet.com>

Leigh Daniels wrote:
>I'm just taking the plunge into astrophotography and I have a quite a few
>questions. Given my usual observing location and a 7" LX200 f/15 scope,
>I'm primarily interested in planetary photography, although I'd like to
>try some deep sky stuff, too. I have an old OM-1 camera with cable
>release. I have Michael Covington's book on astrophotography.

For prime focus shooting you need to guide the photos on a star because telescope drives are not accurate enough for long exposures unguided. For this you either need an off-axis guider, or a separate guide scope. Off-axis guiders can be a pain to use, and separate guide scopes can have problems with flexure between the two scopes. You pay your money and choose your problems. :-)

>I know I need a piggyback camera mount and an OM-1 T-Ring.

The Lumicon piggyback adapter is about the best you can get without going to a $400 Losmany dovetail system. It is very rigid and can be adjusted slightly in altitude. The one Orion sells is not what is illustrated in their catalog. It is actually a stamped out (rather than cast) bracket that would probably flex if the camera has much weight.

>I'm a little confused by the various adapters available. I see that Meade
>has a Variable-Projection Camera Adapter and that looks like what I want.
>The Meade catalog states that the Camera Adapter will also allow prime
>focus photography. Does this mean that I don't need to buy a #62
>T-Adapter? Is there a better variable camera adapter?

I bought the Orion variable adapter. It seems to be well made. I would recommend mastering prime focus photos before you go to eyepiece projection.

For prime focus shooting I would recommend using a 2" adapter like the Orion #5272 that converts the SCT threads to a 2" back. Then get a T-adapter that is designed for 2" backs. I like the ones Lumicon makes. They are short and vignette less than the one Orion sells. With this setup, you can shoot prime focus. You can put a f/6.3 reducer in front of the 2" adapter. Or, you can use it with a 2" diagonal for 2" eyepieces.

Before you settle on a T-adapter, think about focusing. Viewfinder focusing through the camera is not always accurate enough. Read about knife edge focusing in Michael Covington's book. If you want to spend the money, the SureSharp works well. If you want to do it yourself, you can jury-rig something up much more cheaply. Using the knife edge or Ronchi screen method of focusing on a star will give you good focus for the moon and planets if they are near the star you focus on. Atmospheric conditions or flexure make it advisable to use near by stars for focusing.

>Can I also use the Variable-Projection Camera Adapter with my ETX by
>inserting it into the eyepiece holder or do I need yet another adapter?

You probably couldn't reach focus because it is so long.

>Because my scope is f/15, it seems like the f/6.3 Focal Reducer might
>also be useful. Is this true? Is the Meade reducer OK or is there a
>better one?

A reducer is necessary for any deep sky photography. It is also necessary if you want to get the full moon into a 35mm frame. The f/6.3 reducer will not give you f/6.3 because you are starting with f/15 and not f/10. If I remember correctly, it should bring it down to around f/9.

>With the OM-1, an adapter of some kind and a focal reducer attached, do I
>also really need to buy the 7" set of counterweights? (I can't believe a
>set of weights lists for $140!)

If you do any piggyback shooting counter weights are an absolute necessity. I purchased the Orion Dovetail Counter weight System because it is more versatile than the Meade weights. The one designed for 10" and 11" SCTs (Orion # 5152) fits the 7" Maksutov. Just use one screw at each end and ignore the extra curved adapters. Nylon washers between the dovetail bar and the scope are a good idea.

This balance system is a 2D system that lets you more accurately balance a piggyback camera at all angles of the telescope. I added two small Jack Lalane weights to it rather than buy the Orion extra counterweights. You have to make bushings for the Jack Lalane weights. I've balanced a medium format Pentax 645 with a 200 mm lens on it.

>Is the Beattie Intenscreen-Plus for the OM-1 worth getting?

I bought one, but should have returned it. A slight improvement, but not worth the cost. You should probably follow Chris' suggestion of getting the 1-12.

>Is the Lumicon 2" rear-cell Deep Sky Filter a good idea?

No. Since you are starting at f/9, film is not sensitive enough for deep sky photos with this filter. I don't think it is very useful for planetary imaging.


Subject: Piggy Back AstroPhotography   Top

From: Greg Hartke <ghartkea_tclark.net>

Prime focus astrophotography, whether film or CCD, is such a challenging art that I thought it appropriate to remind possibly intimidated beginners and lurkers how easy it can be to get rewarding astrophotos via the piggybacking of a camera with a telephoto lens on, for example, an LX200. This is a great way to get started in astrophotography and is *really* easy with this telescope. To accomplish this, I set up recently to do some piggyback work, paying attention to my techniques and equipment so I could describe them to beginners.

First, the equipment I used:

10" f/6.3 LX200
Meade Superwedge
Tuthill Precision Polar Axis Finder
Losmandy 2-D counterweight system with extra 5# weight Meade Piggyback mounting bracket
Swivel-tilt piggyback adapter, Bogen #3232 (from Orion) Meade Series 4000 9 mm illuminated Reticle EP (eyepiece)
Nikon FM SLR camera
Nikkor 80-200 mm f/4.5 zoom lens
Cable release
Foam dew shield (home made)
Rob Roy's LX200 joystick

A few comments about the equipment:
The Meade Superwedge has received its share of nasty comments. The truth is it's as rigid as only a cast unit can be, as all recognize. The complaints arise from the less than precise altitude and azimuth adjustment mechanisms. This is really not a big deal 'til you're making an effort to do a *perfect* drift alignment to the celestial pole, then it'll definitely have you talking to yourself. (There's a lot of slop to be taken up when reversing directions in the adjustment process.) The unit would be considerably improved if this were fixed. However, for the work described here, more precision is unnecessary. Alignment at this level, I find, is very fast and painless.
The Tuthill polar finder is really not necessary but it makes it so easy to start the polar alignment process that I'm glad I have it anyway. This device is, in essence, a plate with a rifle scope thru it with the optical axis of the scope precisely orthogonal to the plate. The plate is bolted to the back of the wedge such that the polar scope would (hopefully) be exactly orthogonal to the base of the wedge, hence parallel to the RA axis of the main scope. The center of the cross hairs in the polar scope is very precisely offset from the optical axis so that when oriented correctly (a simple matter, determined from a table provided by Tuthill), the cross hairs can be set exactly on Polaris leaving the wedge pointed exactly at the celestial pole. In practice, I've never found it to work to a very high degree of precision even though I've tried to use it very carefully.

There are critical assumptions built into the device:

(1) The base plate of the wedge must be of exactly uniform thickness. The main scope is bolted to one side of the base plate and the polar finder to the other. If the base plate of the wedge is not of exactly uniform thickness, clearly the optical axis of the polar scope will not be orthogonal to the front surface of the wedge where the main scope will sit.

(2) The RA axis of the main scope is obviously assumed to be exactly orthogonal to the base plate of the telescope itself.

In mass produced items, I can't imagine either of these assumptions being true with any regularity to the degree necessary to get very good polar alignment. Actually, I think a really cool device for SCT owners would simply dispense with the carefully offset cross hairs and mount a simple finder scope with centered cross hairs such that its optical axis is exactly orthogonal to the same kind of mounting plate as the Tuthill unit. Mount it the same as the Tuthill unit and center Polaris on the cross hairs. What's the point? Well, without any extra equipment it's a real pain in the butt with the LX200 to do the initial rough alignment with Polaris in the finderscope. The finderscope is always in a hideously uncomfortable position. With the initial alignment via the polar scope on the wedge (well oriented and positioned for comfortable alignment), it's a very simple matter to fine tune the adjustments to get Polaris in the finder, and thence in the FOV of the EP in the main scope. The bottom line is that I find the Tuthill unit very well made but it can be (but isn't necessarily!) easily defeated by mass-production dimension errors. Here's irony for you: I think it's hideously overpriced but I'm *really* glad I have one. Figure that one out!

Good balance is essential to the long term health of your telescope drive systems. Repeat that. Chant it. Adopt it as your mantra. It's true. If you're going to hang extra equipment on your scope, you *must* have a 2-D balance system. The Losmandy unit is *very* nice. I found the camera w/telephoto lens to be too heavy for the standard 2.5# weight so I bought the extra 5# weight from Spectra. Perfect. Editor's Note: there are several designs for making your own 2-D Counter Weight System on the AstroDesigns homepage.

When I bought my LX200 from the Nature Company, they included a bunch of extra items including the Meade piggyback bracket. Works fine with the Bogen model 3232 swivel-tilt adapter I bought from Orion. I have to confess, though, I lust after the 3-axis piggyback mount from Losmandy. That would sure make composition easier. (A 2-axis mount like I have is a bit limited.) One of these days I'm going to get one of these from Spectra.

I like the Meade Series 4000 9 mm illuminated reticle EP. Fortunately, I bought the version that is *not* battery powered. Mine plugs into the LX200 control panel so that it's brightness can be controlled from the keypad. Very cool, and useful because you can turn the brightness level down low for dim guide stars. (I have sensitive eyes anyway and don't need much illumination.)

As many of us have on this list, I made the dew shield from a foam pad I picked up at a backpacking store I frequent. The foam is approx. 1/2" thick. I glued Velcro down the sides to hold it together when mounted on the scope and use a wrap of Velcro tape to snug it around the end of the OTA. (This keeps it from winging away on the wind. Imagine my consternation the first time *that* happened! Random neighbors also enjoyed watching me chase it. Added to my reputation, that's for sure.)

I also have a similar dew shield I made for the camera lens, then forgot to mount it for this session. Dummy. I hope no one else makes the same mistake.

Any beginner that doesn't know about the LX200 joystick made by MAPUG's own Rob Roy is missing something important. There are lots of people here who do without one but I'd be lost without mine. It's an inexpensive little mechanical contrivance (very nicely made) that slips over the keypad and engages the NESW keys when pushed in the appropriate direction. I find it orders of magnitude easier to use than the motion control buttons on the keypad. If I had to give up all other accessories and keep one, this would be it.

Don't underestimate how long it will take to put everything together, particularly if you're working alone. Working at a leisurely pace, it takes me almost an hour to gather and assemble all the bits and pieces for an evening's work. I like to do this well before sunset which makes orientation of the tripod an interesting endeavor since you can't see Polaris. I first site the tripod, orienting it by using the compass that came with the wedge. Of course, I move well away from the tripod (20 feet or so) to eliminate magnetic effects from all that metal. (Don't forget to set the magnetic declination of the compass for your site! See the Meade manual for details. It's a piece of cake.) Using the compass, I go directly south of the tripod and then orient the tripod along that sight line. It doesn't have to be precise: The point of this exercise is to get the tripod positioned such that the available travel of the wedge controls will not be exceeded when precise alignment is made. When satisfied with the orientation, level the tripod (necessary for accurate LX200 refraction corrections). I use a small torpedo level I picked up for a couple of bucks from a hardware store. The bubble level on the wedge itself is useless without recalibration.

The wedge is then bolted to the tripod and the scope mounted on the wedge. Mount the usual equipment (finderscope, diagonal, and dew shield). You're now ready to mount the piggyback bracket. This is easily done by removing (in my case) 4 Allen screws from the periphery of the rear of the OTA and using 2 of these to mount the bracket. The swivel head is then screwed to the mounting bracket and the camera is mounted on the swivel head. You'll need to lock the dec and RA axes for this so make sure the bracket and camera are approximately over the center of the fork so not too much force from the now-out-of-balance scope is placed on the gears. Next mount the counterweight and release the dec lock to balance the scope. (You might just as well put an EP in the diagonal for this.) Point the OTA straight up and screw the counterweight in or out until the scope moves the same amount to the north and south in response to a small push. Next point the OTA horizontally, then move the counterweight up or down it's track along the underside of the OTA until the scope is similarly balanced in this direction. You're done. See? Balancing is easy with the Losmandy unit.

Now wait for it to be dark enough that you can see Polaris. (You can use the time to set your slew speed to less than the system maximum to save wear and tear on the drive systems and check your telescope system clock.) I first use the Tuthill polar axis finder (which only gets me close, but very conveniently does so), then I use the stock LX200 alignment routine. My experience, though, is that it's easy to significantly improve alignment by then using Philip Perkin's once-popular iterative alignment procedure. This methodology has fallen a bit from favor because inconsistencies in the telescope mechanics can keep it from converging to perfect alignment. Philip himself now prefers a good drift alignment. Of course, he's correct: That *is* the best method for precision alignment. However, my experience is that alignment with the stock Meade routine is not nearly as good as might be expected and the iterative alignment improves it significantly in no more than a few iterations, with a total time investment of less than 5 minutes (with just a little bit of practice). This works fabulously for piggyback photography where ultimate alignment precision is usually not really necessary.

Philip's iterative alignment scheme is very simple. (I actually do this using the 26 mm Series 4000 Plossl EP that came with the scope. This seems to be sufficient for me.) Command the scope to go to a star with a significantly different RA than Polaris. (I used Pollux (Star 81), which is approx. 5 1/2 hours east of Polaris in RA and is close enough that slewing to it from Polaris is done quickly.) Center the star using the NESW keys then sync by pressing and holding ENTER 'til the display says "coordinates matched". Next command the star to go to Polaris (Star 19). Don't touch the NESW keys! Use the wedge controls to move the center of the FOV of the EP (which the system thinks should be coincident with the position of Polaris) halfway to Polaris. (On rare occasions, I've been far enough off at this step that Polaris wasn't in the FOV. Shame on me. I was careless somewhere along the line. Simple solution: Use the finder scope for this step instead of the view thru the main scope. It works fine.) Now command the scope to go back to Pollux. Center and sync. Repeat the procedure of commanding motion to Polaris, moving Polaris halfway to the center of the FOV with only the wedge controls, then going back to Poleax, centering with the NESW keys, then Syncing. I find that after about 3 iterations, Polaris is close enough to the center of the FOV that I'm ready to rock and roll.

I probably should use the reticle EP for the alignment, but what's the point? I use it for drift alignment, to be sure, but the iterative scheme, as mentioned, is probably not capable of that kind of precision. No need to obsess here when it's unnecessary and experience has shown me that the 26 mm EP is ample for this work.

The easy part: Taking the photographs.
Honestly, with the LX200, this is really easy. After I'm properly aligned, I usually point the scope at a star bright enough that I can see it thru the viewfinder of the camera. I then adjust the camera mount so the star (centered in the scope) is centered in the camera field. No worries about mis-aiming that way! I did all my shots that night at 200 mm and f/4.5. Before mounting the camera, I put a small piece of duct tape on the camera barrel to hold the focal length of the zoom lens at 200 mm and another small piece to keep the focus at infinity.

Insert the reticle EP. I find it useful to orient the crossed lines of the reticle in the cardinal directions. I then hold my keypad such that the NESW movements of the joystick are parallel to the cross hairs. This way, when you use the keypad to move the scope, a centered guide star always moves directly along the cross hairs. If the guide star drifts, say, to the left, I push the joystick to the left to move the center of the FOV towards the star. It's very natural to guide this way.

I suggest when you open the camera shutter for an exposure using the cable release that you cover the camera lens while the vibrations damp out. I just use my hand, although at various times I've used a piece of cardboard.

Now you're ready to aim and fire away. I did 10 minutes exposures of The Double Cluster (h and chi Persei), The Pleiades (M45), the M36-M38 region of Auriga, M42, the area just south of zeta Orionis where the Horsehead Nebula lurks, and the Rosette (N2237) in Monoceros. I didn't shoot longer than 10 minutes for fear of fogging the film. (My skies aren't bad but they're less than pristine.) Experience will tell you what works for you and your skies.

The polar alignment must have been pretty good because I didn't have to do much correcting in declination. (Actually, this is pretty typical when I do it this way but it does get better still with a good drift alignment.) It was quite easy to keep the guide star in the center box of the 9 mm reticle EP. Actually, guiding like this is overkill when shooting with a 200 mm lens if your polar alignment is as good as mine was, but it's always good practice. Guide stars are easy to find when doing piggyback photography because you never have to move the FOV very far to find something suitable. Since the field of view of the telephoto lens is really pretty darned wide (of the order of several degrees), moving the FOV of the main scope up to a half a degree hardly affects composition.

Keep in mind I did all of this without training PEC, either. I figured beginners wouldn't need the added complexity so I tried to keep it simple and omitted its use. In fact, this is how you get practice guiding so you can train your own PEC. Believe me, guiding is an art that improves with lots of practice.

Piggyback photography is an aspect of astrophotography that's easy to overlook but is a wonderful first step for beginners into this arcane art. There are all sorts of fabulous subjects. In the appropriate season, you can shoot the North American and Pelican Nebulae, M31, M33, lots of fun areas of the Milky Way in Scutum and Sagittarius, etc. You can learn a lot about your equipment this way, get the practice necessary before moving to prime focus photography, and collect lots of neat photos along the way. Experiment with film, especially color. It will all be valuable experience in the long run! If you decide to move on to prime focus photography, you will have gone a long way in the development of the skills necessary to be successful. I read of owners who have little scope experience and run out and buy an LX200 and CCD camera and then go not-so-slowly nuts trying to get everything working, learn the rudiments of observational astronomy and telescope usage, while simultaneously trying to gain the skills necessary to the art. I wonder how they ever manage: Taking it one step at a time is much less frustrating and can be quite relaxing and downright fun.

Once you try doing this with the LX200, you can't help but be amazed at how easy it is. I've been an amateur astronomer for over 30 years (in and out as time and location permitted, of course) so I remember the bad old days very well. Boy, was it *hard* back then.

The best reason to own an LX200 is for its photographic capabilities; that's why I bought mine. If I were solely interested in visual observations of DSOs, I'd get a good, fast 18" Dob, and maybe put encoders on it. (I've paid my dues starhopping over the years.) It wouldn't cost much more than an LX200 and I'd have a *superb* visual instrument. If you've been intimidated about doing astrophotography with your LX200, try some piggyback photography. You'll quickly build up a stock of good photos so you can redecorate your house and wow your friends!


Subject: Guiding Techniques Articles    Top

From: Philip Perkins

I've added three new articles to my web site which are accessible as follows: "Guiding Techniques for Astrophotography"-- A beginners overview of guiding concepts and systems followed by a detailed description of guiding techniques based around the LX200, GEG, and ST-4. Supplemented by photos and diagrams: <http://www.astrocruise.com/guide.htm> Note: should open a new browser window over this one.

"Instructions And Tips For Using the ST-4 Autoguider"-- To supplement the above article, here is the excellent article on the ST-4 by James Janusz, which is reproduced with Jim's kind permission:

There's also a short article about the "Michael Stecker Astrophotography Competition":  <http://www.astrocruise.com/msastro.htm> All of these are also accessible from the front page. Hope they may be of some interest or use, and please let me know if you discover any problems.

A good site for drift aligning:


Subject: Helpful Hints for Astrophotography   Top

From: Chris Vedeler <cvedelera_tix.netcom.com>
and: Scott Tucker

Scott, and Chris have much to share about their experiences in astrophotography with the LX200.
Check their web sites for many hints.



Subject: LX200 Astrophotography Websites    Top

From: Chris Vedeler

Note: new windows should open over this one as you select links.
Philip Perkins has probably the best images taken with an LX200: <http://www.astrocruise.com/>

Howard Anderson also has some of the best images taken with an LX200: <http://www.astroshow.com/>

Andy Steere has some impressive images too: <http://astro.umsystem.edu/andy/>

Of course if you are talking about the 16" LX200 Jason Ware is "The Man":

And last but not least, is my webpage: <http://www.isomedia.com/homes/cvedeler/space.htm>

For the super impressive, jaw dropping astrophotos, they are almost all taken with APO refractors or Schmidt Cameras. In terms of image quality, and wide vistas a SCT can't compare.


Subject: Film Camera Selection Criteria   Top

From: David Samuel <samuelda_tbigpond.net.au> Date: Dec 2001

I think that I was the one who mentioned the Topcon camera in reply to an earlier post.

The reason I mentioned it is as follows. About the year 1976 I was looking for a camera to purchase which I could use for astrophotography as well as for taking everyday type pictures. My requirements for astrophotography were that the camera should have at least the following features (not in any order of preference):

  1. Mirror lockup (mirror flip causes about 90% of camera vibrations - more in some cameras)
  2. Interchangeable focusing screens (needed different types for astrophotography and every day photography)
  3. Interchangeable viewfinders (needed different types for astrophotography and every day photography)
  4. Interchangeable lenses (so that I could take the lens off before attaching the camera to the back of my telescope)
  5. Total manual exposure controls (for both shutter speed and aperture)
  6. Mechanical shutter mechanism (no need for batteries)
  7. Good range of shutter speeds including the ability to leave the shutter open indefinitely
  8. Accuracy and precision of shutter speeds
  9. Quality (I intended to keep this camera for a long while and did not mind paying a little more up front for that convenience)

The available cameras (in Australia at the time) I looked at were:

  1. Olympus OM-1 (relatively cheap, but discounted this because of no interchangeable viewfinder)
  2. Topcon D (satisfied all of my requirements mentioned above, a good camera overall, discounted this because I thought the two camera companies mentioned below would be around longer and for the reasons that I decided to purchase the Nikon)
  3. Cannon F-1 (satisfied all my requirements mentioned above, an excellent camera overall, discounted for the reasons that I decided to purchase the Nikon)
  4. Nikon F2 (satisfied all my requirements mentioned above, an excellent camera overall, purchased this one)

It finally came down to a choice between the Nikon F2 and the Canon F-1. I decided to purchase the Nikon F2 because:

  1. It satisfied all my requirements mentioned above
  2. Test reports in camera magazines indicated it had the more precise shutter speeds
  3. The image in the viewfinder showed 100% of the image that would appear on the film. All the other cameras show about 90-something percent of the image. This would allow me to frame my images more accurately with the equipment I had and give me the feeling that I had better control over my framing.
  4. The Nikon F2 had a wider range of shutter speeds available.
  5. The Nikon F series had a good reputation as a quality camera.
  6. I am sure that there were other reasons which I have forgotten in the last 25 years.

The main disadvantage of the Nikon, Canon, and Topcon cameras at the time was that they were all highly priced (the Olympus was much cheaper).

So finally to answer your question, even though I have not used the Topcon, I am fairly certain that it will do a good job for astrophotography. Since you will be purchasing a second hand camera you should ensure that you can get hold of all the accessories you will need with it. The accessories should include appropriate lenses (if you wish to do wide field astrophotography), focusing screen, viewfinder, and attachment ring to the telescope. There are other accessories such as a cable release and an attachment to mount the camera on the outside of the telescope tube (if you wish to do wide field astrophotography) that are common to most 35mm cameras which will not affect the decision of which model of camera to purchase.

What you will find hard to judge is the condition of the camera you purchase without being able to inspect it properly. This is however the same problem when purchasing any second hand camera. Still for $50 the most you can loose is $50 plus the cost of the telescope adaptor ring (specific to the camera you purchase).


Subject: Where to Process Film Images --part 1 of 3   Top

From: Kevin Wigell <kwemaila_ttwcny.rr.com>

----- Original Message -----
From: "Phil" <psdisk@comcast.net>
> I know local places like Ritz and other small camera shops don't do a good
> job of developing our night shots. Can someone recommend a reliable place
> where I can send slides to have developed. A place that has a good
> reputation for this type of work?
----- End of Original Message -----

I regularly have my print film developed at a 1-hour place at a local drugstore. The problem with developing astrophotos isn't getting the film developed - it's getting them printed. Rarely will a photo shop print an astrophoto correctly. Developing the film itself is a very standard process, and it's pretty hard to screw it up. The biggest danger in getting astrophotos developed (the film part) is that they will cut right through the middle of your exposures when they cut the film. So what I always do is wait for the film to come out of the machine and then tell them to just hand the negative right over to me.

Then I take the negatives home, cut them myself, and scan them myself using a film negative scanner. Then I can work on them on the PC (in Photoshop or whatever), and either print them on a printer or post them on my web site (www.kwastronomy.com).

But you said your film is slide, which most 1-hour places can't do because it's a different process. You have several choices. One would be to send your exposed film off to Tony Hallas (www.astrophoto.com), who is a professional film processor and astrophotographer extraordinaire. He will do an excellent job developing and mounting your slides. Another option would be to take your exposed film to a local professional film shop. These can generally be found in the yellow pages. They are specialized photography shops and is usually their only business. Unless you live way out in the sticks you should be able to find one relatively nearby. Then you can either explain to them that you have astrophotos and they should take great care in cutting the developed film, or you can ask them to just give you the developed film uncut, then you can cut and mount the slides yourself.


Subject: Where to Process Film Images --part 2

From: "ScopeTrader.com" <rharrisa_telvis.com>

SnapFish.com if it's digital or film. I've been real happy with the results from there.


Subject: Where to Process Film Images --part 3 of 3   Top

From: Gene Horr <genehorra_ttexas.net>

Tony Hallas is one of the best in the world, but you are likely dealing with mailing everything in.

My next choice would be a local custom lab. Unless they are experienced your initial results will still be poor but they will be willing to work with you, redoing the prints until they get it right. They'll usually allow you to work with one of their techs so that you can request the same person each time. It's more expensive, but not _that_ much more and in the end you will get great results. Plus the negatives have the lowest chance of getting damaged.

Last of all try one of the local cheapo one-hour labs. One where you can actually talk to the tech yourself. The drug stores can work well with these. Go during a slow period and bring a print to show the tech what you are looking for. Sweet talk them. Help them by showing what is wrong with the prints. It will take longer than the pro lab techs as you are generally working with people not too far up from minimum wage, but you can generally get them trained in a reasonable amount of time. The main problems with this method are that the techs generally don't stay at the same place for extended periods of time and the treatment of the negatives is often less than professional.

If you are in the learning stage go with the cheapo source unless you live around the corner from a pro lab. The faster turnaround, convenience, and cost is IMO worth the somewhat larger risk and training factor. But if you are at the stage where you are wanting to hang images up on the wall spend the extra time and money to go with the pro lab. You don't want to risk ruining that perfect image because someone doesn't know how to properly treat a negative.

But ask around at your local club first. Someone may have already trained a tech for you <g>.

Another thought is to DIY. Even film positive processing is fairly easy nowadays.

If you aren't already a member you might want to consider joining the astro-photo-mailing list. It is an excellent source of information for film imaging. <http://www.seds.org/mailman/listinfo/astro-photo/> at the bottom of the page.


Subject: Calculating F/Ratio with Eyepiece Projection      Top

1. f ratio=focal length/aperture

2. With a reducer multiply the above by .63 (or whatever the reduction factor is for your reducer).

3. For positive eyepiece projection f/ratio=Mep*f

where Mep = the magnification of the eyepiece projection setup calculated as follows:

Mep = (D-Fep)/Fep where:
D = the distance from the eyepiece to the film plane (typically 100 to 150mm with a variable tele-extender). Measure it with a ruler or tape.
Fep = the focal length of the eyepiece.
f = the f ratio of the telescope.
Here's an eyepiece projection example with an f/10 telescope and a 10mm eyepiece located 110mm from the film plane:
>From formula #3: 10*10=100

So the overall f/ratio for this setup is f/100, which is a good f/ratio to start with for planetary photography on film.

If you're using your Pictor instead of film, try using a 2X Barlow instead of an eyepiece. This is called negative projection. Don't use a tele-extender...just slide the Pictor into the eyepiece holder of the Barlow. The f/ratio will be the f/ratio of the telescope * the Barlow factor. In this case an f/10 scope will be f/20.


Subject: FOV in 35mm Camera?      Top

From: Allen Ginzburg <allenga_tsco.COM>

>Does anyone have handy an approximate field of view of a 35mm SLR camera when used for
>prime focus photography for a 8" LX200 f/10, 2000mm focal length, 200mm mirror.

If I remember correctly, the formula is

field size = 2*atan (film size / (2* flocal length)) * 60

Where film size and focal length are in mm and field size is in arcminutes.

In the 8" LX200 case at 2000 mm with 35mm film, the field size we get 60.2 arcminutes, or about 1 degree.


Subject: Back focus/JMI/Van Slyke Slide Mirror      Top

From: R. A. Greiner

More info is available at my website
    A new browser window should open over this page.

I have been working on a scheme to get very solid attachments for the LX200 which allow focus, mirror viewing use of a reducer and use of any camera, photographic or CCD, all at the same time. I have found a solution which is, I think, worth sharing. I have a 12" LX200 permanently mounted on a wedge. I wanted to be able to have mirror viewing and immediate return to the imaging element. Additionally, I wanted everything very solid and with full 2" aperture for 35mm photography.

I have just received a very ingenious mirror box from Van Slyke Engineering. It is called the Slider. He has made a rock solid box with a mirror that slides sideways so as to minimize the thickness of the box. This can be used with the JMI focusser, a focal reducer, the mirror box and any camera, 35mm or CCD. and still maintain the 100mm back focus required by the Meade focal reducer. It is 2" all the way. This is a wonderfully rigid and compact system. I can recommend it highly to imagers for all purposes. As a additional note, I have also taken delivery of Van Slykes 26mm illuminated eyepiece. It is very nice even though a bit expensive. His machinery is of the highest quality.

Van Slyke web page: <http://www.observatory.org/vsengr.htm>


Subject: New Evaluation Page of Filters       Top

From: Leroy Guatney <lwlguatneya_tusa.net> Date: Apr 2002

Here's the direct link:
    Note: should open a new browser window over this one.

For now, heaviest emphasis is on colored filters. Other types have been covered elsewhere, but mine is the first I've seen on these.


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