Alt-Az Suitable for astrophoto?

This is where you can read up the answers to some FAQs on astronomy and star-gazing in Singapore. Members' contributions are welcomed.
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cataclysm
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Post by cataclysm »

Note that you would need to polar align the Astrotrac. In Singapore I do not know how to do that yet..
I gave much thought to that too, always wanted a grab and go mount for travel and widefield astrophoto, but it seems there is no easy way around it at our latitude. That's why I still settled for a good old eq mount. :mryellow:
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weixing
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Post by weixing »

Hi,
VinSnr wrote:
Tachyon wrote:
ariefm71 wrote:I doubt ioptron is up to the task, use http://www.astrotrac.com/
Note that you would need to polar align the Astrotrac. In Singapore I do not know how to do that yet.. [smilie=confused.gif]
I written to the MD of astrotrac regarding this as well.

Actually with GPS and hence all the GOTO capability, why didn't someone come out with an automatic polar align mount by now?
I think might not be practical as the mount will be very big and need a lot of power... imagine the mount need to adjust the azimuth and the altitude of the mount with all the scope on top of the mount.

Anyway, those GOTO system should know the polar alignment error after star alignment and should at least display the information for user to correct the polar alignment if the user need it.

By the way, I think the old SkySensor 2000 does have a polar alignment assist feature which help you to correct the polar alignment after star alignment, but I guess it still not good enough for astrophotography.

Have a nice day.
Yang Weixing
:mrgreen: "The universe is composed mainly of hydrogen and ignorance." :mrgreen:
superiorstream
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Post by superiorstream »

Hi,Everybody
I do agree that for serious astrophotographer;especially those who want to capture galaxy,star cloud and perhaps want to help out in research programs like searching for exoplanets, then a GOOD STABLE EQ MOUNT with accurate electronic guiding is essential.However just for hobby purposes we need less complicated items.I for one believe that something simple will get more into the hobby.Amateur astronomy was my lifetime hobby and till now I only use ALT-AZ mount for astrophotography and basically use the afocal method because its cheap--the very camera you use for taking the daily pic can be use.Of course you photo cant come near to the big guys who use LOSMANDY or PARAMOUNT mount but who cares--there is no big prize to be won!Its only a hobby and for personal satisfaction only.For roughly what can be achieve using ONLY ALT_AZ mount and AFOCAL ONLY, and shoot ONLY in SINGAPORE--of course with great patience.See my photo at
www.chia-astroblog.blogspot.com.With this method the only star cloud you can see is M42 and basically WHAT YOU SEE IS WHAT YOU GET IN YOUR PHOTO.Thanks for reading.
oxygn
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Post by oxygn »

actually it is doable.

Hyperstar configuration with alt-azi tracking mount can give you decent pics.
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cloud_cover
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Post by cloud_cover »

What's the budget like and what are your intended targets? :)
Generally the brighter the object the less demanding it is on the mount and camera
Your exposure time determines how robust your tracking needs to be so if you can shorten your exposure time - by reducing the f number, increasing the sensitivity of your chip, cooling your camera or increasing your total imaging time by oincreasing the number of pics taken - you can use a less robust (read cheaper) setup :)
DON'T PANIC
superiorstream
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Post by superiorstream »

The key to ALTZ mount only "astrophotography" are
1)A goog steady ALTZ mount;at least with a payload of 10 KG
2)A good scope with a large aperture--at least 4 in to 11 in and must be light.You can use a good achromat with a good eyepiece that correct those optical defects.
3)Since you are going to do short exposure;get a high ISO camera that show low noise in the dark.You are in afocal astrophotography.
What you see is what you get.
NOTE--Dont expect to get photo of galaxy etc;you cant see those--only a fuzzy patch,so in your photo you get that too.
Want to get those textbook coloured astrophoto--well,ask those pro like Remus,and be prepared to spend on computers/updated programs/ccd/DSLR/apo refractors etc.Thanks and my 2 cents.
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orly_andico
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Post by orly_andico »

wow zombie thread!

although agreed, a hyperstar configuration (f/2) can do amazing things. your typical 30-second image at f/5.6 can be done in 4 seconds. With 4-second exposure times, you will not see field rotation.

too bad the starizona device costs a lot (as much as a C9.25 tube).
Robin Lee
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Post by Robin Lee »

orly_andico wrote:wow zombie thread!

although agreed, a hyperstar configuration (f/2) can do amazing things. your typical 30-second image at f/5.6 can be done in 4 seconds. With 4-second exposure times, you will not see field rotation.

too bad the starizona device costs a lot (as much as a C9.25 tube).
But the idea of having f/2 configuration is tempting. Though, it might be a pain to focus if your stock focuser is nasty which happens to be the case overtime.

Anyway, alt-az mount is perfect for solar and planetary imaging and you are limited to very bright deep sky object if you choose to stay on alt-az. An Orion Atlas or Sirius costs as much as an iOptron, no?
Clear skies,
Robin.

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