ULF Walk-in Camera?

[mvanderaa]

Hello:
It's been a while since I've been active on the forum, and I have limited experience with large format. I am a high school photography instructor and would like to construct a walk-in camera for my students. The goal is to help student's learn by actually making and developing an image all while inside the "camera". I was hoping to use Harman's direct positive paper by special ordering a roll (24" x 66 feet).

My first thought was to build a large room with a front standard, bellows, and bed mounted on the front wall, and projecting the image inside to the rear wall. The bellows with front standard would give us the ability to fine focus. HOWEVER, I would like the student's to make close-up portraits. At an image size of 20x24", this would be larger than 1:1, perhaps at least 2:1? Using the Schneider XXL 1100mm as an example, I'm guessing I'd need more than 11 feet from the lens to the wall. If we were to shoot using direct positive paper, I'm wondering if this is even feasible given the ultra slow nature of the direct positive paper and the "bellows" factor? We have six 1,000ws Profoto heads, but even this may not be enough light!?

When I talk about close-up portraits I'm suggesting a 20x24" image which is the subject's chin to brow. Any insight or guidance on how to approach a walk-in camera for ULF portraits of this nature will be appreciated. (The walk-in will be helpful to develop the image in trays right inside the "camera", thus it functioning as a darkroom as well.) Thank you in advance.

[Jeff Donald]

When I was teaching at a university, I had a student use a box that a large refrigerator/freezer is shipped in to make a pinhole camera. Two people could stand in the camera during taking the photo, even burning or dodging. Once the exposure was made, the paper was rolled into a tube and processed in the schools darkroom.

[mvanderaa]

Thanks, Jeff. Your solution was far more practical than mine. However, it makes me wonder how large of a pinhole camera I could effectively make? Perhaps pinhole would be a better solution.

[Dan Fromm]

At 1:1, film plane to subject distance is 4 focal lengths plus the lens' internodal distance. With an 1100 mm lens, ignoring the internodal distance gives 4.4 m, a bit over 13 feet. At 2:1, 4.52 focal lengths.

You don't need such a long lens to cover 20x24 at 1:1, but with a shorter lens the dark side of your room cam will be shorter too. The formula is: extension = focal length * (magnification + 1). At 2:1, the lens' rear node to subject distance is 3 focal lengths. FWIW, I b'lieve that Richard Learoyd, an exponent of room cams for enormous scale portraiture, uses a 760 Apo Ronar.

Remember that a pinhole's focal length is the pinhole-to-film plane distance, also that pinholes have infinite depth of fuzziness. Why don't you play with a pinhole in an otherwise covered window, a helper outside and a sheet of white foamcore inside the room. Move helper and foamcore around to see how the dim image looks at various focal lengths (foamcore-to-window distance) and magnifications (helper-to-window distances). I abhor pinholes, but it might do what you want.

[Pere Casals]

We have six 1,000ws Profoto heads, but even this may not be enough light!?


Test it with a DSLR, the XXL is F/22, so take a DSLR at ISO 100 and F/22 and check what flash power / distance you need.

The paper may have some ISO 6, so have to check if the flash power / distance factor can be multiplied by 16, this is 4 stops. My guess is that you will have enough power if not using a softbox.

You know... if flash to subject distance is 1/2 then light power is x4, the square law.

Anyway you can do it also with continuous light and a long exposure, a fixture may be used to help subject stay still.

Regards.

[mvanderaa]

Thank you, Dan and Pere. My experience with the direct positive paper in 8x10 suggests I can probably (but barely) get enough light? I will test it. However, to Dan's point, while I have read that shorter focal lengths can be more practical at this ULF size, wouldn't that create significant distortion of the subject, especially at 2:1?

[mvanderaa]

BTW, Dan: I wasn't familiar with Richard Learoyd's work. His portraits are stunning. I found this video which gives a glimpse into his process https://www.youtube.com/watch?v=1Z589aji2LE Thank you for sharing his name.

[Andrew Plume]

A few years ago I was very fortunate to meet Richard at his East London Studio (shown in the you tube clip) and at that time he was printing images on the 'machine' shown in the video - he's truly a great Artist

good luck with your Project and best regards

Andrew

[Lou Baleur]

the barrel version of the 1100 xxl is f14--so it buys you a bit over a stop of light. You can do direct positives on regular photographic paper if you use reversal bleach and develop as reversal--expect to get about iso 3 or 2--you will need a lot of light or time or a combination of both. I suggest direct sunlight as the source and do short-ish time exposures. the xxl will cover to get you life size at 1:1.

addendum--I checked my notes and I got about iso 6 with faster (multicontrast) regular paper / reversal development and using electronic flash.

[mvanderaa]

Thanks, Lou. Regular paper may be better. My experience with 8x10 direct positive paper is it's close to ISO 1.5. I did a fast but fun test tonight with my 8x10. I took the back off and placed a soccer ball about 12" in front of the lens. In order to focus on the wall that the camera was projecting on to, the front of the lens was approx. 77" from the wall. This was able to reproduce the soccer ball quite large. It was also approximated the size of my subject's head (closer to 2:1). Here was the problem: I put a couple v-flats on either side of lens to block the light and simulate my front wall, and was left with no workable room to place my lights (only 12" of room in front of the lens). I'm wondering Dan Fromm: If I was to use a 600mm (twice the focal length of my test tonight) does that automatically imply I'd have 24" from lens to subject and need 144" of "bellows"?

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[Dan Fromm]

Michael, measure from the lens' diaphragm, not from the front, whatever that means. This because most LF lenses' nodes are close to the diaphragm. The front node, from which lens-to-subject distance is calculated, will be a little in front of the diaphragm. The rear node will be a little behind the diaphragm.

I take it that you used a 300 mm (12") +/- lens. Since distances given magnification are calculated in focal lengths, doubling the focal length will double all distances, holding magnification constant.

About measurements and such. The closest the rear node can be to the film plane is one focal length. The subject will then be at infinity. This is, in fact, one definition of focal length. The closest the front node can be to the film plane is one focal length. The film plane will then be infinitely far from the rear node. Your measurements are a bit, um, sloppy.

About good practice. Lenses intended for general purpose use, such as the ungodly expensive XXL 1100 are optimized for a big subject in front and a small (relatively) negative behind. When used at magnifications > 1:1, there will be a small (relatively) subject in front and a large negative behind. To get the most out of the lens' optimizations when working above 1:1 the lens reversed.

To be fair, the XL 1100 is a dialyte and might be nearly or perfectly symmetrical. Quick check, compare the two cells' focal lengths. Equal means symmetrical, doesn't have to be reversed for > 1:1.

There's a big exception. Dialyte type process lenses, e.g., Apo-Artars, symmetrical type Apo-Nikkors, Apo-Ronars and Repro-Clarons, are perfectly symmetrical and don't have to be reversed when used above 1:1. Plasmat- and Dagor-type process lenses are also perfectly symmetrical but the likely ones, G-Clarons, are too short for your application. Apo-Tessars and clones are asymmetrical and should be reversed when used above 1:1.

[aaronnate]

I turned my classroom into a camera obscura one year. Totally blew the kids away once their eyes adjusted and they were 5th graders.

It requires a window to the outside world.

Blackout the classroom. Cut a dime sized hole in the covering of the window and wait. The smaller the hole the better the focus but it takes a long time for the eyes to adjust. What sized lens does Ian Ruhter use?

[mvanderaa]

Hi Aaronnate: I'm jealous of this idea. The only view outside my classroom is into a very small and shallow courtyard, which I don't think will make a very interesting images. There are other classrooms in the building, however, that would work great.

[Tin Can]

1/2 the class could pose in the courtyard with others inside.

Don't limit your photography to film, use phones to capture the image obscura both with still and video.


Hi Aaronnate: I'm jealous of this idea. The only view outside my classroom is into a very small and shallow courtyard, which I don't think will make a very interesting images. There are other classrooms in the building, however, that would work great.

[aaronnate]

Hi Aaronnate: I'm jealous of this idea. The only view outside my classroom is into a very small and shallow courtyard, which I don't think will make a very interesting images. There are other classrooms in the building, however, that would work great.

There is the challenge. Make it interesting. Make the students make it interesting. Whatever is in the courtyard will be projected into the room. The classroom I did this in had a great view, fall folliage, shapely trees against a deep red mesa. When I moved, my next classroom had what I called a prison yard view; cement and red brick. I chose not to do this because it was boring. I should have because, one day I looked out, two students were sitting against the wall and it was the most amazing image. The next year I switched subjects and rooms, and the project did not fit the standards or the dictated program.

Randy has some good ideas too.

[DougD]

If you are interested in a camera obscura, these folks have a product to help out. (no affiliation other than I bought one).
https://bonfoton.com/

[Tin Can]

What a great simple product and something actually affordable!

I will be getting 2 soon for my cargo trailer.


If you are interested in a camera obscura, these folks have a product to help out. (no affiliation other than I bought one).
https://bonfoton.com/

[aaronnate]

If you are interested in a camera obscura, these folks have a product to help out. (no affiliation other than I bought one).
https://bonfoton.com/

Awesome!!!!

[mvanderaa]

Thanks for sharing that product, Doug. I'm going to order one to play with. I also just purchased an 800mm f/9 Apo-Ronar to play with. My interest here goes beyond the obscura — I'd like to see if we can make large direct positives. The 800mm seemed like an economical way to do some testing. (I was able to get a nice, bright image circle larger than 1:1 with the 300 on my 8x10, but will lose one stop with the 800 and that's not taking into account "bellows" extension.) I have a handy-man stopping by this weekend to help with a hole in the classroom wall out to the hallway (instead of the courtyard) so we can set-up our studio strobes for portraiture. I've sketched-out how I want the hole trimmed and a simple rig to accommodate rise / fall. To get up and running fast, I'll use a magnetic chalkboard on casters to mount the paper and try to focus, although I recognize I'll never get the chalkboard perfectly parallel to the lens. All said, it seems like the best and least expensive way to do some down-and-dirty testing and then I can pivot from there. I'll keep this thread updated with my progress. Thanks to everyone who chimed-in!

[mvanderaa]

I turned my classroom into a camera obscura one year. Totally blew the kids away once their eyes adjusted and they were 5th graders.

It requires a window to the outside world.

Blackout the classroom. Cut a dime sized hole in the covering of the window and wait. The smaller the hole the better the focus but it takes a long time for the eyes to adjust. What sized lens does Ian Ruhter use?

I'm sure (but not certain) Ian's lens is huge. I'm also in the suburbs of Chicago which means a lens pointing towards our narrow and bland courtyard doesn't work for portraits during the winter months. (I would love to have a room with a view of some movement / cars — that would persuade me to do the obscura. If you've seen my latest post, you'll see I'm headed a different direction with a lens. BTW, I showed an Ian Ruhter video to my students — they were fascinated. It's cool stuff. Thanks, Aaronnate!

[Tin Can]

My Chicago Logan Sq store front was 100% blacked out for Darkroom and studio.

I installed a 6" hole in what i thought would be a good location facing south at the Bloomingdale Bike Trail (https://www.traillink.com/trail/bloomingdale-trail-(the-606)/)aka 606. The bike path plans includes a staircase to the upper level right where I was. My lens would have had a great stage.

They never built the stairs. My view obscura became way busier after the 606 opened...with cars...crime increased drastically. I sold 2 years ago and went downstate.

I bought this lens specifically for the hole. Scroll down to the 790 mm Mammoth lens. http://re-inventedphotoequip.com/Formats.html

I never used it for a big negative or print, but did use white foam core to watch the cars.

I like your plans gentlemen!

[mvanderaa]

Too bad they never built the stairs, and I’m sad to hear of the crime. That lens is interesting! An image circle of 1,830mm at a subject distance of 10 feet! Wow. Did you ever do any more with the lens?

[Tin Can]

I was soundly thrashed when I posted my first 8X10 with it here. Missed focus evidently. I have problems with soft focus lenses. I have tried a few...They resemble my vision.

I have used it in the Chicago studio with 11X14 at all f stops.

I plan to use in forest here but will never post anything soft focus again. :)

[Dan Fromm]

I'm sure (but not certain) Ian's lens is huge. I'm also in the suburbs of Chicago which means a lens pointing towards our narrow and bland courtyard doesn't work for portraits during the winter months. (I would love to have a room with a view of some movement / cars — that would persuade me to do the obscura. If you've seen my latest post, you'll see I'm headed a different direction with a lens. BTW, I showed an Ian Ruhter video to my students — they were fascinated. It's cool stuff. Thanks, Aaronnate!

I think I've read that he uses an 1800 Apo-Nikkor, could be mistaken.

[mvanderaa]

800 Apo-Ronar f/9 arrived. Working through with a handy-man how to build into the wall with rise / fall, and think we have a pretty simple but solid solution figured out. Will keep you updated on my progress. Thanks.
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[AF-ULF]

I have done something similar. I used an artist easel to hold the paper or film. It could be moved back and forth to focus, so you don't need bellows or any other mechanism to move the lens. Put a sheet of white paper on the easel, move it to focus. Then switch out the focus paper with the photo paper and take the photo.

[aaronnate]

That is a huge lens! Glod for you. What is the image circle?

[MAubrey]

That is a huge lens! Glod for you. What is the image circle?

APO-Ronars have 45° of coverage at infinity at f/22. So, the 800mm would have about a 660mm image circle.

[Dan Fromm]

APO-Ronars have 45° of coverage at infinity at f/22. So, the 800mm would have about a 660mm image circle.

Not to pick nits, but Apo-Ronars' coverage declines with focal length. R'stock claims that the 800/9 Apo Ronar covers 42° @f/32, also that its focal length is 788 mm. So it covers a 605 mm circle. Not a teeny tiny difference, but for the OP's purposes probably still a distinction without a difference.

[mvanderaa]

As I understand it, process lenses (including the Apo Ronar) are quoted in Rodenstock literature at 1:1 and at infinity. There is a lot of misleading information on the various forums about actual coverage, however, I did find an old Rodenstock brochure that listed it's coverage as 28x36" at 1:1 (at f/22 for most lenses, but stated at f/32 for focal lengths longer than 760). Much less coverage at infinity.
AF-ULF: Glad to hear you had success with your project! I'm sure my exposures will be quite long, but I'm thinking this is doable.

[MAubrey]

Not to pick nits, but Apo-Ronars' coverage declines with focal length. R'stock claims that the 800/9 Apo Ronar covers 42° @f/32, also that its focal length is 788 mm. So it covers a 605 mm circle. Not a teeny tiny difference, but for the OP's purposes probably still a distinction without a difference.

No, definitely nit-pick here. It's good to have accurate numbers for image circles!

Thanks.

[mvanderaa]

Hello: I'm resurrecting this thread as I finally was able to make an image with my 800mm Ronar. After leaving my teaching position to take a Marketing job with the school I work for, I lost access to the photography studio. This forced me to find an alternate location and new approach.

I built a box frame out of aluminum tubes and covered it with black canvas. I mounted the lens on one end and placed a 30x40" easel on casters inside of the camera. (BTW, the 32" Ronar covered the entire easel.) Focussing was difficult. While not thrilled with the images, I was able to make some portraits using 16x20" direct positive paper. (I simply placed the developing trays right inside the camera.) See attached images.

I have a number of ideas to improve the process, including the focussing. This proof of concept tells me it's worth fine-tuning. I think I'll be able to get some really nice images in the future.

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[Tin Can]

Basement Faraday Cage?

Remember Image circle increases as subject gets closer.

I now have a plan for Living room size camera, thanks to you!

It is already nearly black out as studio, I can tighten the blackout easily.

More when I do more

[diversey]

A nice setup and great portraits! I was thinking to buy an ice fishing tent to use my 48" lens.


Hello: I'm resurrecting this thread as I finally was able to make an image with my 800mm Ronar. After leaving my teaching position to take a Marketing job with the school I work for, I lost access to the photography studio. This forced me to find an alternate location and new approach.

I built a box frame out of aluminum tubes and covered it with black canvas. I mounted the lens on one end and placed a 30x40" easel on casters inside of the camera. (BTW, the 32" Ronar covered the entire easel.) Focussing was difficult. While not thrilled with the images, I was able to make some portraits using 16x20" direct positive paper. (I simply placed the developing trays right inside the camera.) See attached images.

I have a number of ideas to improve the process, including the focussing. This proof of concept tells me it's worth fine-tuning. I think I'll be able to get some really nice images in the future.

210239
210240
210241
210242

[wallpaperviking]

the barrel version of the 1100 xxl is f14--so it buys you a bit over a stop of light. You can do direct positives on regular photographic paper if you use reversal bleach and develop as reversal--expect to get about iso 3 or 2--you will need a lot of light or time or a combination of both. I suggest direct sunlight as the source and do short-ish time exposures. the xxl will cover to get you life size at 1:1.

addendum--I checked my notes and I got about iso 6 with faster (multicontrast) regular paper / reversal development and using electronic flash.

Just came across this thread, some fascinating ideas.... :)

Is this reversal process what Richard Learoyd would use for his latest B/W work?

https://fraenkelgallery.com/exhibitions/richard-learoyd-the-outside-world

Thanks! :)

[Marco Annaratone]

I am not sure whether the creation of Susanna Kraus has been mentioned already ... it's here, in Berlin.

https://www.imagocamera.com/imago-fotour/?lang=en

[Tin Can]

Yes we have seen it

but I love to see it again and again

Wonderful!



I am not sure whether the creation of Susanna Kraus has been mentioned already ... it's here, in Berlin.

https://www.imagocamera.com/imago-fotour/?lang=en

[jnantz]

isn't there an abe morell book about turning a room into a camera?