Alt az mounts

[astro_dog]

i own a symax 127 on a celestron slt mount. Is it possible to do any deep sky imaging on this setup?

If so does anyone have any tips on the best equipment to get started on a budget. I dont want to spend a fortune as i dont have much photographic experience. Is a reasonably priced Dlsr the best bet?

If this wasnt the best for dso imaging, i was possibly thinking of getting the neximage planetary imaging package, in the hope this would be a cheap way of getting started imaging something while i save for more equipment. Has anyone used it? any good?

I know i probably need a better mount and other equipment, but i dont want to get until i at least have some idea of what i'm doing. All i have done so far is piggybacked a compact for lunar images.

Any tips would be appreciated, thanks

[JimStan]

In general, an Alt-Az mount is going to introduce an artifact called "field rotation" to your images. If you try to take more than about a 30 second image, the stars near the edges of the picture will appear to be making small "streaks" as the earth turns and the stars sweep through the field of view.

You might have a bit more luck trying to take planetary or especially moon pictures, since the exposure times can be very short, as compared to those needed for deep sky objects.

But unfortunately, an Alt-Az mount is really not suited for astro-photography, except in a very limited way.

AFA DSLR vs CCD Astro-cameras, unless you are willing to pay almost as much for a CCD camera as you would for a DSLR, you will find the images to probably be somewhat inferior to those you can get with a DSLR. Although, I must say that those who have a lot of experience and have gained a lot of knowledge as to taking photos with CCD cameras, are capable of producing some very fine shots.

However, be prepared for a steep learning curve, and keep in mind that those really terrific shots that you see on this forum, have been taken, for the most part, by guys and gals that have spent many hours honing their craft !

Good luck! Jim S.

[Macavity]

See above. I think you would gain *exerience* with devices like the NexImage (or similar) but, as you surmise, sensitivity is limited and targets are likely to be restricted to the moon and "brighter" planets. Modern DSLRs are doubtless lighter than "in my day" (LOL), but might be a bit of a challenge to the fore-aft balancing of mounts such as yours... and may not be vastly more sensitive?

Another (real) possibility is VIDEO astronomy. The cameras are small and light AND sensitive. Exposure times (for individual frames) are lessened, so strategies to deal with (lessened) field rotation are possible. Sadly, off the shelf, you are faced with an outlay of £300 for the (good) entry level Minitron etc.

I learned a lot with, but frankly rather quickly "outgrew", e.g. an Orion "solar system imager". The NexImage is probably the best deal (most sensitive) of the ilk? I did decide to work with VIDEO astronomy though. It gave me a nice record of many DSO targets, with a MAK127 (150), at a (fairly!) mid-range price... I don't need a fast APO, an EQ6 mount etc.

[ollypenrice]

With your slow f ratio I wouldn't invest much in DS imaging in Alt Az. You'll need long exposures and the field rotation will then be a killer. However, you can do good stuff with a fast frame camera.

Olly

[jgs001]

The accepted answer is not really. However, don't let that put you off . I started out imaging with a NexStar SLT mount, you are limited thanks to field roration, as Olly said, but work out the limits of the system, go up to them and work within them and you'll get some great results. The 127 Mak is not really going to work well for you though, as Olly said, it's too slow, but get a dovetail bar, and mount the camera with a lens directly to it will work great. I used to use an ST80 (400mm, f/5) on a NexStar SLT and that worked nicely. I've posted some images in the Modest kit DSO thread, or let me know and I can dig you out a couple.

It's all good experience anyway, both in setting up, capturing and processing the data.

[Shibby]

I started out imaging with a NexStar SLT mount, you are limited thanks to field roration, as Olly said, but work out the limits of the system, go up to them and work within them and you'll get some great results.

I second this. Use what kit you have to practise. I try to never upgrade until I am certain I have made the most of what kit I have and fully reached the limitations of it.

I first tried DSO imaging on an Alt-Az mount - managed to get subs up to about a minute (had to trash a lot of them, but when each takes only a minute you can quickly get enough to stack for a result).

[PunkJay]

See above. I think you would gain *exerience* with devices like the NexImage (or similar) but, as you surmise, sensitivity is limited and targets are likely to be restricted to the moon and "brighter" planets. Modern DSLRs are doubtless lighter than "in my day" (LOL), but might be a bit of a challenge to the fore-aft balancing of mounts such as yours... and may not be vastly more sensitive?

Another (real) possibility is VIDEO astronomy. The cameras are small and light AND sensitive. Exposure times (for individual frames) are lessened, so strategies to deal with (lessened) field rotation are possible. Sadly, off the shelf, you are faced with an outlay of £300 for the (good) entry level Minitron etc.

I learned a lot with, but frankly rather quickly "outgrew", e.g. an Orion "solar system imager". The NexImage is probably the best deal (most sensitive) of the ilk? I did decide to work with VIDEO astronomy though. It gave me a nice record of many DSO targets, with a MAK127 (150), at a (fairly!) mid-range price... I don't need a fast APO, an EQ6 mount etc.

A good alternative to the Minitron (and a lot cheaper) is the Samsung SCB-2000. Have a look at the Video Astronomy social group here on SGL - there are a load of friendly and helpful members who will be happy to help you out.

Contrary to popular opinion, deep sky imaging is possible with an alt/az mount, as long as you are aware of the limitations....

cs,

- Jason

[Macavity]

Contrary to popular opinion, deep sky imaging is possible with an alt/az mount, as long as you are aware of the limitations...

A point worth underlining.

Registax (doubtfully?), Deep Sky Stacker (explicitly!) claim / or actually DO, seem to cope with rotations re. the shorter (10 sec max) frames of *video* astronomy. Field Rotation limits vary quite a lot, in a non-trivial way over the sky though? Always worth a try... Get lucky?

A problem seems to be that there very few decent, medium LOAD bearing Alt-Az mounts. The Skywatcher ones are limited to a MAK127, ST102 etc. It's hard to add extra accessories to the payload. I had significant success with the Ioptron MiniTower. It can take a MAK150, a C8, but can be a bit temperamental, in default state.

Eventually, reluctantly, I gravitated to an HEQ5. A fine thing, but I doubt I will

ever find it (any equatorial!) a true "joy to use". But just me, in a sense...

[Baffa]

I have the slt mount but I must say the tracking is so bad so I couldn't even manage 10 sec subs without it creating streaks and other anomalies.

It could be just my mount, the az motor have died twice so I got fed up and removed the motor all together now and just use it as a manual alt/az mount with a broom stick as control

I will get a proper mount later this year!

[jgs001]

You have to weight the system up so it's "tail" heavy... i.e. if you have the camera at the rear of the OTA, balance it so that camera end is a little heavier... doesn't need much, but it removes huge amounts of backlash from the system, by ensuring the gears are fully engaged. I tried to "improve" the balance of mine, and got it as nigh on perfect as I could, and my consistent 1 minute subs with only 1 error in maybe 20, went down to errors on every sub over 5 seconds. That's part of finding the limits of the system. I was able to achieve 2 minute non trailed subs on M31 (early in the season) when it was low (20 degrees ish) in the east, although I lost 50% of them to drive errors. I never really used longer than 1 minute exposures in the end, as the drives were not up to it.

DSS will deal with the field rotation between images without any issue whatsoever...

Here's one, note the number of subs...

Here's the M31... ignore the vignetting, this was before I found out about flats.., these were 2 minute subs, and several hours of them... but I don't recall how many.

[astro_dog]

thanks for all the replies. I'm very confused now! I'm no closer to deciding on where to start! The mintron cameras and the phillips sound like a good start as they seem reasonably priced. Do i need proccesing software? i noticed the mintron comes with some software, is this adequate to start?

regarding the focal ratio, would a reducer make my scope better for imaging?

If the cloud ever leaves derby i'd probably pluck up the courage to buy something rather than just dreaming about it!

[jgs001]

For what you have at present... get something like the MS HD lifecam (I think it is) and have a go at the moon and planets... Your kit will be great for that. If you want to try your hand at DSO's then a dSLR is a good bet... a second hand one would be a good start, and you can get reasonable bodies for under £250. Add a kit lens, or a nifty fifty (£70 new) and a medium length dovetail (about £20) and some way to mount the camera to the dovetail (Manfrotto 323 adapters work great) and you'll have a pretty good little widefield setup.

Have a look at MPB Photographic - Buy Used Canon & Used Nikon Digital SLR Cameras, Lenses & More for second hand kit. I've had a number of items from them, as have others into photography on here, never had an issue.

[theghettostylus]

I got the canon 1000d plus 18-55 kit lens very, very good condition for £150 on Amazon, for me its a very good camera, works very well for astro work and the bonus of live view is always... Well a bonus aha

[happy-kat]

You might enjoy this thread.

http://stargazerslounge.com/topic/228101-the-no-eq-dso-challenge/?fromsearch=1