Jump to content


Photo

Large format astrophotography

  • Please log in to reply
45 replies to this topic

#1 Kona

Kona

    Sputnik

  • *****
  • Posts: 41
  • Joined: 22 Oct 2008

Posted 04 October 2013 - 11:18 PM

While not often heard of, astrophotography with a large format 4x5 film camera is achievable and highly satisfying (especially when you see the resulting photographs!) I've been using the big camera to record large swaths of the night sky for some seven years now. I've learned a lot along the way and wanted to share my experiences here on the forum.

This posting is a bit of a catchall and contains information for those not familiar with the cameras. Please pardon the info dump below and keep in mind that the whole point of all of this is the creation of photographs of uncompromising quality. A 4x5 negative easily allows for prints of 16x20 inches with no visible film grain and incredibly high resolution. There are hassles to the process, but when it all works, it works spectacularly.

*********************************************************************

First, there are some limitations to the use of the big camera.

Using a 4x5 limits me more or less to wide field views of the sky. Don't expect to capture a highly magnified Hubble-like frame-filling view of the Lagoon nebula with a 4x5 camera. The simple reason is that there are no telescope optics that will work with these cameras (the image circle is far too small, barely the size of a 35mm frame at best) so the optics are restricted to the lenses made for the camera format itself. The longest practical focal length lens in 4x5 is around 300mm, which in terms of a 35mm SLR camera would be similar to a 105mm mild telephoto lens. Large format lenses are also slower than lenses for 35mm, with most only having a maximum aperture of f/5.6. There are no f/1.4 or f/2 lenses for large format.

Film choices are limited. Sadly as of October 2013 while I write this Fujifilm is the only remaining manufacturer of color transparency (slide) film with Velvia and Provia in 4x5 sizes. For color negative, only Ektar and Portra from Kodak is available. While the future of color film photography doesn't look good, happily there are a goodly number of black and white film emulsions. Black and white has always been the forte of large format, and will continue to be available as the film isn't as technically demanding as color to manufacture. Companies like Ilford and Adox are in the b&w business for the long haul. For astrophotography there is currently an absolutely amazing gem of a black and white film in Fuji Acros 100. Acros is a huge improvement over anything we've ever had in the past.

*********************************************************************

Some technical considerations of the camera.

The film for 4x5 cameras comes in a stack of loose sheets and has to be loaded individually in the dark by hand into reusable film holders. There are no roll films for large format. With the larger physical size of the film comes a problem that occurs during the long exposures of astrophotography: because the film is a loose sheet without the benefit of rollers or tension from a long roll, the sheet can (and will) flex, shift and move around inside the film holder while a lengthy exposure is being made. This leads to stars that are streaked or gradually bubble into and out of focus over various parts the film.

The best solution for this is a vacuum film holder. These aren't commercially made, so it's a do-it-yourself project (but it's not too difficult!) Basically the setup takes an ordinary 4x5 film holder and converts it into a specialized camera vacuum back. The procedure is to drill small holes through the back of the film holder and attach a low powered (also homemade) vacuum to suck the film down absolutely flat against the back of the holder. The vacuum also holds the film fast, so it doesn't move or shift at all. The modified holders work great. I've made several of these and can gladly help with construction details.

Movement. Large format cameras by design are made to essentially be turned into pretzels. They're not the rigid blocks that we know of with 35mm SLR cameras. There are flexible, pliable bellows, sliding friction or geared parts and numerous rotating points of axis where the camera can be adjusted. These cameras are made to be fully adjustable from the supports of the lens out front to the rear of the camera where the film is placed. For astrophotography these numerous multiple moving parts can be a liability--you absolutely don't want anything moving or shifting around potentially turning stars into streaks. With that in mind...

In the choice of large format cameras, there are two major types: field and monorail. Field cameras fold up into compact box like shapes, are lightweight and are easily carried afar. Monorails are larger and use a single robust rail as a backbone of sorts and are primarily (but not always) used in studio settings where compact size and weight aren't concerns. Field cameras are traditionally made of wood. Monorails are always made of metal.

For astrophotography monorails are excellent. They're much more stable for heavy lenses, such as the 300mm mentioned way above. The controls lock down tighter than those of wood (important to minimize any shifting and movement) and the cameras are much less expensive to buy used. They are however large, heavy and bulky. Avoid a camera with a round center rail, as the standards for the front and back still wiggle even when locked down. Square or H-shaped center rails are preferable.

Wood field cameras are undeniably gorgeous. However because of the lightweight construction they're limited to smaller, lighter lenses and must be braced or reenforced limiting any flexure to use for astrophotography. I have to stress this again: the camera will flex and bend minutely at the joints where it folds up so you must use some additional reenforcement (I use a rigid dovetail plate) of some kind. Otherwise, you'll never get pinpoint sharp stars with a field camera. Choose a camera carefully. The feature of greater portability typically means field cameras cost three times what a monorail does. Field cameras are a wonderful choice if you want to also use the camera for landscape photography.

*********************************************************************

My setup:

I use an old Meade LXD75 equatorial mount that's been soldiering on for me for many years. It's not prestigious, it's got some warts and peculiarities, I've had to alter and repair a few bits over time but it still works pretty well. Would I like an Astro-Physics or a Losmandy? Absolutely! Yet the cantankerous old LXD75 has proven sturdy, the tripod is good and at forty pounds of weight (with the counterweights and camera removed) the mount isn't excessively heavy to move and carry around.

Anything attached to the mount is secured with two or more bolts. The task is to eliminate any and all sources of unnecessary movement and flexure. The resolution of the 4x5 camera is utterly amazing, so the stronger all the connections are and the more solid the mount is the better the camera will perform.

The advantage of the GEM type mount is that it is so accommodating in what can be put on it. I'm using a short dovetail plate on the top of the mount in a side by side setup for a camera and guidescope. I use both monorail and field type cameras. The camera sits in a secondary Losmandy GM8 saddle that lets me balance the camera by sliding its plate front to back while simultaneously serving as a quick release. On the other side, I'm using a 66mm refractor permanently mounted to the dovetail plate. The 66mm is a nice little scope that provides a bright and easily viewed image for my 12mm reticle crosshair eyepiece. There's plenty of magnification for guiding and I've never had a need for anything more powerful.

Also affixed on the dovetail between the guidescope and camera is a green laser pointer which I use to quickly slew the mount by eye to bright guide stars--the laser and guidescope are exactly aligned. The laser pointer makes finding guidestars (and verifying where the camera is pointed) extremely easy and quick.

I manually guide the mount. Tracking is smooth enough that I only need glances in the reticle eyepiece to verify my guidestar is exactly where it should be. Corrections in RA are made with the mounts' simple electronic hand box at guide speed. I don't bother with go-to for the mount.

Everything is battery powered. The mount runs on a ordinary D-cell battery pack which amazingly enough lasts entire seasons without needing new cells. The illuminated reticle in the guidescope works on button cells. Laser on AAA alkalines. Even the vacuum for the camera runs on batteries so I don't have to mess with any extension cords. Everything is portable. Going out the door I'll have the mount assembled, polar aligned, powered on and running in fifteen minutes or less.

*********************************************************************

I've likely missed some details. Can't do it all in one posting. Anything I can help with for the curious, just ask and I'll do my best.

Attached Files



#2 Kona

Kona

    Sputnik

  • *****
  • Posts: 41
  • Joined: 22 Oct 2008

Posted 04 October 2013 - 11:19 PM

The camera types and vacuum film holder.

Attached Files



#3 Kona

Kona

    Sputnik

  • *****
  • Posts: 41
  • Joined: 22 Oct 2008

Posted 04 October 2013 - 11:20 PM

Film size comparisons.

Attached Files



#4 Kona

Kona

    Sputnik

  • *****
  • Posts: 41
  • Joined: 22 Oct 2008

Posted 04 October 2013 - 11:22 PM

4x5 color transparency example.

Attached Files



#5 Kona

Kona

    Sputnik

  • *****
  • Posts: 41
  • Joined: 22 Oct 2008

Posted 04 October 2013 - 11:23 PM

Black and white print from 4x5 negative.

Attached Files



#6 Kona

Kona

    Sputnik

  • *****
  • Posts: 41
  • Joined: 22 Oct 2008

Posted 04 October 2013 - 11:25 PM

... and one last print. :D

Attached Files



#7 Giorgos

Giorgos

    Vostok 1

  • -----
  • Posts: 175
  • Joined: 14 Jan 2011
  • Loc: Athens, Greece

Posted 05 October 2013 - 12:14 PM

Excellent presentation! I wonder if one really needs a camera? Isn't a wooden box with a lens attached on one side and a sheet film holder at the other just the same for astronomical photography? also old used lenses with inaccurate speeds can be used for the time exposures required for astrophotography?
PS I'd like to see construction details of the vacuum film holder...

#8 Kona

Kona

    Sputnik

  • *****
  • Posts: 41
  • Joined: 22 Oct 2008

Posted 07 October 2013 - 10:37 PM

A camera is nothing more than a light tight box, and if you can build something with enough precision--why not? Just as long as the lens, ground glass and film holder are within tolerance.

What can I help with on the vacuum holder? Materials, how to build?

#9 Giorgos

Giorgos

    Vostok 1

  • -----
  • Posts: 175
  • Joined: 14 Jan 2011
  • Loc: Athens, Greece

Posted 08 October 2013 - 10:51 AM

How to build... I have seen some on the net but I can't figure out how to build one.

#10 Kona

Kona

    Sputnik

  • *****
  • Posts: 41
  • Joined: 22 Oct 2008

Posted 08 October 2013 - 12:56 PM

Giorgos, send me a pm with your email address and I can send some files to you.

#11 Michal1

Michal1

    Ranger 4

  • -----
  • Posts: 390
  • Joined: 25 Jul 2010
  • Loc: Czech Republic, Central Europe

Posted 08 October 2013 - 01:19 PM

Hey, I'm interested, too! I only didn't want to repeat the Giorgos's questions. Please can you put the materials on some public file hosting site (netload, mediafire, ...) so that all can see them? And thanks for your posts, they are very inspiring!

#12 Nightfly

Nightfly

    Apollo

  • -----
  • Posts: 1055
  • Joined: 20 Jun 2007
  • Loc: Dark Skies, Maine

Posted 08 October 2013 - 08:09 PM

An excellent primer on large format astrophotography. Your presentation here and your examples show that it is possible to make outstanding images with what are routinely thought of as cumbersome cameras. Cumbersome maybe, but the quality is outstanding.

Thanks for posting !!

#13 Kona

Kona

    Sputnik

  • *****
  • Posts: 41
  • Joined: 22 Oct 2008

Posted 08 October 2013 - 11:25 PM

Thanks Jim! Better late than never eh? Only took me seven months to get around to it. :brick:

Giorgos, Michal, I just reworked and condensed all my material into a simpler illustrated format. Forum limits the image size but it should still be readable.

Attached Files



#14 Kona

Kona

    Sputnik

  • *****
  • Posts: 41
  • Joined: 22 Oct 2008

Posted 08 October 2013 - 11:27 PM

And the second half. Please let me know any thoughts you may have.

Attached Files



#15 Giorgos

Giorgos

    Vostok 1

  • -----
  • Posts: 175
  • Joined: 14 Jan 2011
  • Loc: Athens, Greece

Posted 10 October 2013 - 01:03 PM

Nice tutorial!

#16 TechPan6415

TechPan6415

    Mariner 2

  • *****
  • Posts: 233
  • Joined: 29 Jul 2012
  • Loc: Aspen, Co

Posted 10 October 2013 - 01:20 PM

Nice presentation, I use 4x5 in my work as a professional photographer. A word on Monorail VS Field, I had a Sinar F2 for about a week, I was considering it for a project on macro scenes that were 1:1 to 3X. Rigid or not, it was just far too heavy to manage, had less bellows extension than my current rig.

I use a Chamonix 45N2 which is made out of a combo of teak, aluminum and carbon fiber. It is *super* rigid, like, it was nearly as rigid as the Sinar but only weighs 3.3 pounds. Now, I don't really do astrophotography because frankly, if I can not claim authorship to an artistic style with it, I am not interested and neither are the people who buy my work. However, I have done some landscapes that include stars and while LF is usable for this, I find using my Hasselblad with proper infinity stops in the lenses and no movements to accidentally bump far more productive. So any loss of image quality in going to a smaller neg is easily made up for by the most important image quality of all, the quality of the talent put into the actual content of the photograph, the overall impact of a brilliant shot versus the mastering of technical attributes in what could be a boring shot.

I am not knocking LF for photographing star fields, but in a day and age in which astrophotography suffers greatly from the problem of lack of creative access and really all looks the same, do you really want even more technical hurdles to overcome when you could be looking at new ways to portray our night sky to who would view your image?

And one other little tidbit, if you are like me and only darkroom print, not digital, pre-exposure dust can be a real downer with sheet film versus roll as you handle the film a *lot* more than any other. This is my number one issue with 4x5 and why medium format is still my overall favorite to shoot with.

#17 Nebhunter

Nebhunter

    Surveyor 1

  • -----
  • Posts: 1926
  • Joined: 04 Oct 2003
  • Loc: Frostbite Falls

Posted 10 October 2013 - 02:54 PM

This is a great effort on your part to make the vacuum system for 4x5. Regardless of what is said about this topic, it is YOUR passion that drives you to do this work. Forge ahead with this plan and "damn the torpedos". Enjoy and share the efforts with us please.

Igor

#18 Kona

Kona

    Sputnik

  • *****
  • Posts: 41
  • Joined: 22 Oct 2008

Posted 10 October 2013 - 03:51 PM

Appreciate the note Igor!

TechPan, thanks for the reply. Reading your post I did want to clarify why I use a large format camera for astrophotography.

Primarily it is simply for the print quality it offers. I never undertook the process for bragging rights nor did I do so with the intention to make some kind of technical statement. However I did want to show it's feasible and offer solutions to its use.

I've stubbornly worked out the process as I do print in a darkroom. I've always enjoyed and loved the craft of making prints by hand. In my mind's eye for a very long time I've always envisioned a smooth toned, highly detailed print of constellations, nebulas and DSOs. I merely wanted to put in a top-quality print of what I see when I look up at the night sky. I began my astrophotography task about fifteen years ago with a 35mm camera and progressed to where I am today. It took the extra resolution and film size of the large format camera to allow my vision of a large, grainless and detailed print (wow does "vision" sound silly). The big camera can be a goober and it did take a lot of trial and error to figure out how to make it work reliably for astrophotography, but when it works, it really is astounding.

Digital astrophotography is the norm for a reason. I doubt anyone reading this is going to pick up a large format camera and do any of this work. I've been in it for the long haul because I love darkroom work and developing my own film. Yet who knows; I did want to show that the use of a large format camera was possible, and the results can be beautiful.

Re: tidbit. Oh yes, I know and have suffered from dust on sheet film well. Cleanliness is the only remedy. To load film I use a film changing tent--a few passes of a sticky lint roller is all that's needed to keep the interior meticulously clean and all dust at bay. The film holders are equally kept immaculate. A static brush and blast of canned air takes care of that. The holders are also kept in sealed plastic bags until use. That takes care of 99.9% of any dust problems.

#19 TechPan6415

TechPan6415

    Mariner 2

  • *****
  • Posts: 233
  • Joined: 29 Jul 2012
  • Loc: Aspen, Co

Posted 10 October 2013 - 05:14 PM

Re: tidbit. Oh yes, I know and have suffered from dust on sheet film well. Cleanliness is the only remedy. To load film I use a film changing tent--a few passes of a sticky lint roller is all that's needed to keep the interior meticulously clean and all dust at bay. The film holders are equally kept immaculate. A static brush and blast of canned air takes care of that. The holders are also kept in sealed plastic bags until use. That takes care of 99.9% of any dust problems.


Yep, I do that too, but when you live and work at 8,000-14,000 feet, the air becomes dry and it gets a lot harder to keep it at bay, I end up "dust bracketing" critical scenes just to make sure..:-)

I am not knocking astrophotography or using 4x5 to do it, I really like your vacuum holder idea, could work great for some of the day long multi-exposure work I do.

I just wish that out of all the genre's of photography I see, astro work could be taken to another level in terms of content, but until one of us can shoot the Milky Way from the surface of the moon or a Jupiter rise from Callisto, most of it will be too tightly shot to impart any form of narrative.

But yes, PLEASE keep shooting film and hand crafting it in a darkroom, I need these materials to stick around in order for me to earn a living, 4x5 film included, LOL!

Maybe I will take my 135 Apo Sironar S and go shoot some moonlit star trails in the desert this weekend, it is starting to snow here...

#20 Nebhunter

Nebhunter

    Surveyor 1

  • -----
  • Posts: 1926
  • Joined: 04 Oct 2003
  • Loc: Frostbite Falls

Posted 11 October 2013 - 09:10 PM

I saw some moonlight trails long exposure work awhile ago, and should look for that link again. Jim found it and what wonderful frame resulted. Only the desert could offer this kind of opportunity. Please do so, and post them here.

Igor

#21 nodalpoint

nodalpoint

    Apollo

  • *****
  • Posts: 1168
  • Joined: 03 Jun 2013
  • Loc: FEMA camp

Posted 22 October 2013 - 07:20 PM

Just noticed this thread. Kona, awesome work. Great to see you using your view camera. I've been thinking of throwing my 4x5 on my mount and having some fun.

I'm a professional myself with a fine arts background and know at least one well-known, highly regarded artist doing similar work who's widely exhibited and at the top of the food chain. Plus, a young artist I spoke with recently was inquiring about just the kind of thing you're doing in order to make images to use in combination with other work. So what you're doing is great and I want to see more!

#22 Kona

Kona

    Sputnik

  • *****
  • Posts: 41
  • Joined: 22 Oct 2008

Posted 24 October 2013 - 08:58 PM

Thanks kindly NodalPoint. Glad to hear my efforts have been of inspiration to you.

I also use my 4x5 camera for general photo work and landscapes (Ansel Adams type stuff, even the paper and chemistry) so I don't use the camera solely for astrophotography.

Who's this well known artist? It would be interesting to see what's being done on that level.

(Professional = actually getting paid for your work!) :)

#23 gillmj24

gillmj24

    Aurora

  • *****
  • Posts: 4913
  • Joined: 06 Dec 2005
  • Loc: PA

Posted 24 October 2013 - 09:53 PM

Thanks for your posts. I've gotten into medium and large format the last year or so though not yet for astro work. I have a Sinar C 4x5.

#24 Kona

Kona

    Sputnik

  • *****
  • Posts: 41
  • Joined: 22 Oct 2008

Posted 26 October 2013 - 02:53 PM

Thank you Gillmj. Good to see folks interested in MF and LF!

#25 Michal1

Michal1

    Ranger 4

  • -----
  • Posts: 390
  • Joined: 25 Jul 2010
  • Loc: Czech Republic, Central Europe

Posted 09 November 2013 - 06:35 PM

Another large format user. Wow!






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics