Re: Large format Astrophotography
I'm lucky to have fairly dark skies here. Can see the Milky Way in my front yard. Well at least as long as the kids next door aren't having a party...
Saw some star clusters tonight which was awesome. Just the C8 and 24mm eyepiece. Did a fairly good rough-and-tumble polar alignment and seemed to keep tracking well enough.
Still don't have a mount for my DSLR as they are out of stock everywhere. It's cool just seeing for now.
Re: Large format Astrophotography
One item for film and glass plates is that 100 years from now they will still hold the data and be useful for science. We will be lucky if a jpg or tiff is readable in a hundred years. Many programs and the rules they created are able to be read now.
Again, it's not a big deal to attach the camera to the back end of scope for prime focus imaging. You can do a lot of science with film astronomy as I pointed out earlier.
And most importantly because I can. It can have a wow factor, especially when projecting a 4x5 image or larger onto a screen.
Also to keep the craft alive. There are millions of glass plates being stored and scanned in to digital archives. They are still revealing new information today from 150 years ago!
The main reason the web cams work iis they take and stack hundreds if not thousands of frames.
Larger pixels can help, but also hide errors. I used to do ray tracing for an infrared camera at NASA that was to be hooked up to the Keck telescope.
There are light pollution filters you can get for your camera from Astronomy and other places. Not good for visual, but for photography can be awesome.
For visual an f/4 or f/2 can be brighter, bu5 unless you have expensive corrective optics there will be a lot of field l distortion such as spherical aberrations, coma (point sources near edges look like seagulls)
Visually may not be a problem for most, but for imaging will suck.
Best combo is a focal reducer to take an f/10 or f/8 to f/5 or faster.
Re: Large format Astrophotography
Schmidt-Cassegrain telescopes are terrible optics. They are designed around convenience of size, not optical quality. They can only illuminate a 35mm frame, and even then with terrible vignetting, coma, and field curvature. However, they remain popular as convenience is paramount to most. After shooting with an 8" SCT in the 80s and 90s I decided to just do piggyback work, where the SCT can actually be useful. They make an adequate equatorial platform. The fork mount can breeze through the meridian without the problems of a German Equatorial.
After 2000 I moved to a dark sky site and got to work on shooting the skies. First with 35mm, then medium format. Professional optics makes for great imaging on film. The Pentax 67 is prefered because of the stable film transport. Some have gone further with vacuum backs, but I found them unnecessary.
Alas, most of the good films are gone. Kodak E100S, E200, Tech Pan, Superia CN100, to name but a few. Today, Acros still reigns supreme as the best B&W film ever made ( out of the box) for this application. The new Acros II even sports higher red sensitivity, a plus I never expected.
If you are after large format film work, Kodak TMY-2 is the last holdout available currently. I've done LF astrophotography just to say I did it, but yield to medium format as the king of formats for this work.
Telescopes are just not designed for large film. Most barely cover "full frame". Use optics designed for their formats and they will yield great results. Provided you have good dark skies and a reliable equatorial platform. Let's not also forget, the gumption to do what most would suggest as a waste of time.
Re: Large format Astrophotography
Quote:
Originally Posted by
James Cormier
Telescopes are just not designed for large film.
Home/ amateur telescopes that is... Kodak used to make a whole panopoly of specialist plates for the astrophotography market - I've encountered some in 1/4 plate, recommended on the box to be stored when unprocessed at -18C.
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Re: Large format Astrophotography
There are exceptions of course. Not for the casual astrophotographer.....
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Takahashi BRC250 with 4x5 astrocamera.
Re: Large format Astrophotography
Quote:
Originally Posted by
interneg
Home/ amateur telescopes that is... Kodak used to make a whole panopoly of specialist plates for the astrophotography market - I've encountered some in 1/4 plate, recommended on the box to be stored when unprocessed at -18C.
This is true, even on 35mm rolls. Kodak Spectroscopic Film and plates. Back when professional observatories needed emulsion based work, well into the 1990s. They were all but replaced with Tech Pan, which was fantastic when hypersensitized.
Re: Large format Astrophotography
See this post, from Nodda on the forum. 4x5 glass plate photo of Andromeda, using 24" aerial recon lens:
https://www.instagram.com/p/CEMfz21nXvJ/
Re: Large format Astrophotography
Jason Lane has done some interesting work. I'd be interested in see his setup aimed towards the star clouds of Sagittarius.
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Re: Large format Astrophotography
I mounted a Burke & James 24” f/6 aerial reconnaissance lens in a tube so I could mount it to my telescope. I hacked a 4x5 back onto the Back of the tube. Then I shot a pic of Andromeda Galaxy on Acros 4x5.
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Re: Large format Astrophotography