Large format Astrophotography

[LabRat]

Before you take ANY plunges into the deep end of astrophotography, join a local astro club!!! Don't embark on this alone (unless you prefer misery and expense)...

I'm an older "it ain't worth it unless you get it on a piece of film" kinda guy, but I met a JPL engineer (who is also a amateur astrophotographer) who ask me (an amateur stargazer) how I shoot the sky... I told him I'm a film guy, and he (almost insulted me) that film was dead in astrophotography... He then gave me a demo at the small observatory...

He set up a modest affordable amateur refractor and said about $200 dollars of stuff extra was all you need... A slightly modified webcam, some other odds and ends, FREE software, a laptop, etc... So I'm still feeling a little insulted as this guy is getting a little geeky with me, and I'm thinking "a webcam, oh please"... He's explaining general polar alignment was all that's needed and software does the rest (ugh)...

It was barely fully dark (and air not fully steady yet) and he focuses on Jupiter, a couple of clicks on the laptop, and it starts exposing over a thousand frames (my eyelids hurt from eye rolling)... Then after exposure(s), waiting about 20 min for software to edit frame by frame, getting rid of frames blurred by atmosphere distortion, correcting angular tilts, and stacking hundreds of frames on each other... Finally, image came up, amazing, like it was shot from a mountaintop observatory!!! I was speechless...

He showed me images on his fone of deep space before/after images of familiar constellations shot through a fairly heavy haze layer in the "before" images where the bright stars were BARELY visible over the bluish haze, but the "after" processed images showed MANY tiny pinpoint stars with multicolored nebula streams flowing through them, on a BLACK background... I didn't know what to say when he asked "what do you think"??? He had difficulty trying to explain what happened, but I jumped in thinking that the software had a microdensitometer feature that read minute changes in brightness in the haze layer and then scaled these differences visually... Holy crap!!!

So I departed a believer that film is dead if aiming an imaging optic upward (Dammit)...

You gotta see this in action before your next move...

Oh, and corran, strongly advise not to buy a powerful cat scope... Too much power, small FOV, and too slow to see much... Get a fast, short FL WF scope to see broad sweeps of stars, where the cat tends to overmagnify smaller points... And air is usually not steady enough to get a sharp image at the eyepiece...

Steve K

[James Cormier]

It can be done.....





But I'd recommend medium format vs large format. The advantages of MF include more stable film transport, sharper lenses (at an appropriate f-stop) as well as ease of executing the shot. Once you have mastered that, then you might try LF work.

Contrary to some advice, film is not irrelevant. Good work can still be done, if you are dedicated to the task and desired outcomes. Astrophotography was done, after all, prior to the advent of digital cameras!

[grat]

Contrary to some advice, film is not irrelevant. Good work can still be done, if you are dedicated to the task and desired outcomes. Astrophotography was done, after all, prior to the advent of digital cameras!

Yes-- and photography was done before the invention of flexible emulsions, but it's considerably more difficult.

Digital allows you to take multiple long(ish) exposures, and stack the signal, while eliminating the noise. Periodic error is far less critical. Large, stable optics aren't nearly as necessary. You're still taking multi-hour exposures, but you're breaking it into manageable chunks.

Massive respect to anyone getting results like yours with film-- I know how much effort it takes. But I'd never suggest to a beginner to start with film for astrophotography, not with the options available today.

[Corran]

Oh, and corran, strongly advise not to buy a powerful cat scope... Too much power, small FOV, and too slow to see much... Get a fast, short FL WF scope to see broad sweeps of stars, where the cat tends to overmagnify smaller points... And air is usually not steady enough to get a sharp image at the eyepiece...

Steve K

Disagree Steve, and the used Cat is in the car lol

[James Cormier]

Digital allows you to take multiple long(ish) exposures, and stack the signal, while eliminating the noise. Periodic error is far less critical. Large, stable optics aren't nearly as necessary. You're still taking multi-hour exposures, but you're breaking it into manageable chunks.

Massive respect to anyone getting results like yours with film-- I know how much effort it takes. But I'd never suggest to a beginner to start with film for astrophotography, not with the options available today.

Agreed, but this is a large format film forum. There's plenty of forums out there giving advice for digital methods - like pretty much all of them!

Just trying to maintain the last hold out.

That being said, I've also discouraged many from trying it. Without experience, it's a daunting task.

I put together a blog post some time ago to give some ideas applying to MF work. The OP may get something out of it.

http://nightflyphotography.blogspot....nalog.html?m=1

[Corran]

James does great work!

I will have to re-read your blog. I see the piggyback SCT setup which is what I want to do. Had a peak last night through my "new" 1985 C8 at Saturn and Jupiter just to see something. Lots to do/learn...especially as I'm somewhat worried the drive might be busted...but I will have to sit down and open it up to see.

[Steven Ruttenberg]

Short order film is not dead for astrophotography. Web cams suck! My digital cameras are a color and a mono ASI6200. These will blow doors off any web cam.

Also, can do things digital cannot. One is, there is no noise, no hot/cold pixels. The detail nd information. You can get is amazing. 4x5 is good for me for now. It is a solid mounting.

And for a couple hundred bucks, you won't do much in the way of photography. My scope and used mount shown in picture was 5600 dollars. Not counting adapters, guide camera, off axis guider, a real camera, dslr at a minimum. Filters, software etc. For example, I use Sequence Generator Pro for guide and capture and Pixinsight to combine post process the dark frames, bias frames and light frames. Then final trip thru PS.

With film and guiding squared away I open shutter on camera and 6-8 hours later I am done. if I want, I can repeat this process for many nights with a new sheet of film each time and stack those. Yes you can guild for 8 plus hours straight as long as your mount and setup is spot on.

This will be most advantageous with the Halpha, Hbeta, OIII and SII filters as well as LRGB images.

Digital provides convienence and other aspects not able to be done with film.

Shirt version, each has its own benefits and one should not negate the other.

Where it will get fun is with glass plates!

[Steven Ruttenberg]

Disagree Steve, and the used Cat is in the car lol

My two RCs a 16in and 12 in open truss tube are f/8, my 102mm refractor is f/8 and my 10in SCT is f/10.

As a reference only,these images were taken with the 102mm refractor. 1 image each using a 5DSR. No noise reduction or any real cor correction as these are just practice.

Obviously moon and Andromeda 31.

I plan to start with these as I practice large format.

Eventually I will need to have some adapters made to attach 4x5 to telescope/s for prime focus. That's where it will become really fun.

[Corran]

Steven, I used a very long focal length lens + teleconverters on my FF DSLR to shoot Jupiter a few weeks ago. I've seen tons of images online from webcams that absolutely destroy my $3300 FF DSLR and a lens that would've been several thousand dollars when new and equals roughly what a typical refractor will see in terms of FOV.

There's a rather simple reason for this - the size of the sensor. Since the webcam has a tiny sensor, the tiny planet is imaged "larger" as a percentage of sensor size. My huge lens setup that was hitting 1400mm in focal length gave me an image of Jupiter that was barely a pinprick on the DSLR. And that's just a tiny FF sensor, compared to 4x5. Free yourself from convictions about what does or doesn't "suck" because it doesn't translate to "normal" imaging.

I'm just struggling to figure out what you want to image on your 4x5. I doubt my 4x5 will ever get an image from a telescope. Just going to use regular lenses on it for widefield, after I get comfortable with shooting my Pentax 67, piggyback. It'll be fun. I'm not sure I would be spending time wisely trying to finesse a 4x5 on a scope to get a days-long image of nebulae.

Anyway, skies clear tonight and I just bought a new Exploring Scientific eyepiece so I'm off to actually try polar-aligning my new Celestron C8 . Have fun!

[LabRat]

Yea, whatever works for you!!!

My earlier post was about (mostly) visual viewing where I found that magnification was usually trumped by atmosphere and, but too much just made the image worse, so low magnification was manageable... For my urban viewing, a faster/shorter FL allowed my eye to just make out sweeps of the Milky Way and just see nebula clouds, esp if I had to use a LP filter... I found a f4 scope would just get me to the threshold of seeing it...

Had a cat and decent refractor, great for planetary and moon, but wanted to get out of this solar system... I decided I needed a "light bucket" to see outside this system...

The night air has changed here, now much more turbulent, and don't have a deck with scope storage nearby, because I found the way to increase my odds of finding new stuff was more veiwing over time and keep looking up to spot best viewing opportunities... Liked relaxed direct viewing, so tended to not try to shoot everything... But in retrospect, wish I had shot odd stuff more...

I still have some hope for film, as the "mood" of some veiwing conditions might be captured on film like constellations rising over city lights, "gothic" moons through cloud effects etc... Digital seems to strive for "perfection", but IMHO film has more "feeling"... So I'm not sure which way to go...

Steve K