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Microstock Photography Forum - General => General Photography Discussion => Topic started by: madelaide on May 17, 2012, 18:54

Title: shooting though telescopes
Post by: madelaide on May 17, 2012, 18:54
I'm on my way to a trip to Atacama, where I will have the opportunity to shoot though telescopes. Each person will have just a few minutes, so I want to get ready.

I will google this, but does anyone have any hints?
Title: Re: shooting though telescopes
Post by: peresanz on May 18, 2012, 04:12

Shooting through a telescope is something that requires a lot of practice and experience. Mastering the techniques is a matter of lots of nights spent at the telescope. you also will need a laptop and a secondary camera for guiding (google for 'astrophotography guiding' and you will understand what I'm talking about) if you don't want trailed stars.

These images of mine are the result of about 2h exposure each.

http://www.shutterstock.com/pic-93874816/stock-photo-horsehead-nebula-and-flaming-tree-in-the-constellation-orion.html (http://www.shutterstock.com/pic-93874816/stock-photo-horsehead-nebula-and-flaming-tree-in-the-constellation-orion.html)

http://www.shutterstock.com/cat.mhtml?gallery_id=324529#id=73197181 (http://www.shutterstock.com/cat.mhtml?gallery_id=324529#id=73197181)
 
It appears that you will have the opportunity to use the telescope just a few minutes. If so, I would recommend to take wide angle shots of the mighty milky way (can be breathtaking at Atacama desert!) by means of a piggyback mount (google for 'pigyback astrophotography'). This is an easier technique and produces very rewarding images.
Title: Re: shooting though telescopes
Post by: Mantis on May 18, 2012, 05:16
The biggest challenge with this kind of work is time and motion.  The earth's rotation limits your time for composition.  Also camera shake is amplified a bazillion times using a telescope. 

1. If possible use mirror lock up (helps reduce shake).
2. Use the timer shutter release or a wireless release.
3. Use the highest shutter speed possible since you won't have f-stop control anyway.  The telescope IS your lens and doesn't have aperture control.

And be sure that you (or someone) has a mount ring to match your camera with the telescope so you can attach your camera.

Hope that helps.
Title: Re: shooting though telescopes
Post by: peresanz on May 18, 2012, 05:36

3. Use the highest shutter speed possible since you won't have f-stop control anyway.  The telescope IS your lens and doesn't have aperture control.


Mantis,

Shooting the stars (nebulae, galaxies, clusters and so on) means that you are capturing just a few photons, you are working at extreme dark conditions. Your remark number 3. should say just the opposite:  'Use bulb mode for as much time as the quality of the mount permits'. This is assuming that the mount is motorized and correctly aligned to the Polar star, which I'm pretty sure will be the case. Even in that case you will need guiding hardware if you want to take exposures longer than say, a couple of minutes. That's why I recommended wide shots because they are more tolerant to guiding errors.
Title: Re: shooting though telescopes
Post by: Mantis on May 18, 2012, 10:38

3. Use the highest shutter speed possible since you won't have f-stop control anyway.  The telescope IS your lens and doesn't have aperture control.


Mantis,

Shooting the stars (nebulae, galaxies, clusters and so on) means that you are capturing just a few photons, you are working at extreme dark conditions. Your remark number 3. should say just the opposite:  'Use bulb mode for as much time as the quality of the mount permits'. This is assuming that the mount is motorized and correctly aligned to the Polar star, which I'm pretty sure will be the case. Even in that case you will need guiding hardware if you want to take exposures longer than say, a couple of minutes. That's why I recommended wide shots because they are more tolerant to guiding errors.

It depends on what you are shooting.  Sun and moon require #3, deep space clearly the opposite.  I should have noted that. 
Title: Re: shooting though telescopes
Post by: madelaide on June 04, 2012, 21:17
Back from the Atacama.  I read your replies along the way - thank you for them - just was not able to reply.

Actually the guy doing the star lecture did the photos himself and there was no adaptor, just shooting through the viewer (eyepice, maybe it's the correct name?). The crescent moon looks great, not very sharp but good filling all the frame. Saturn, taken from another telescope, is not quiite sharp. I tried photographing a star myself from one of the telescopes, it didn't get any exciting. I should have tried one of the nebulae or a sample of the Milky Way.

I had taken my tripod, but they had a table with a head in it, so I used it for a long exposure trail shot. 25min however was enough for the crescent moon to brighten the background excessively.

The following days I took some nice sky shots using a technique I read in a couple of sites: largest aperture, ISO1600, 30s exposure. I do get a slighty motion on the stars, but if kep small enough the image looks nice, At least on the camera - I haven't downloaded them yet.  Pity I didn't know this technique before, that could have given me some nice shots in Africa years ago.

It was fun anyway - and what an amazing sky!
Title: Re: shooting though telescopes
Post by: Mantis on June 05, 2012, 07:58
Glad you had fun! Post some shots if you can.
Title: Re: shooting though telescopes
Post by: madelaide on June 20, 2012, 17:20
I've been quite busy since I returned, having a friend visiting me (what also became a photo opportunity) and the Rio+20 summit (lots of exhibitions), so I only have photos from Santa Cruz de la Sierra so far:

http://www.flickr.com/photos/adelaidephotos/sets/72157630116128608/ (http://www.flickr.com/photos/adelaidephotos/sets/72157630116128608/)