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tiphaine
7-May-2020, 04:19
Hi all,

I've been lurking here quite a few times in the past, looking for insights about ULF. I'm really interested in ULF projects like Ian Ruther a or Kurt Moser did. I'm a french professional photographer, I also teach in a school of photography. Here is my website : www.tiphainebuccino.com

My project
No electricity, no photography. No oil, no photography. No plastic, no photography. One night, as I was looking for sleep, I wondered why there isn't it already a "green" photography. I mean, today all is rebranded with an ecological bias. There will be a day soon that some big brand come to you with a greenwhashed camera and our conscience will be happy.

I started wondering: "what a real ecologic way to make photography ?" Short answer, there is none. You can just be careful, use less.

I then began to imagine a photography that can work autonomously. I wanted to be autonomous (Photographic paper is one big question but we come to it later); not depends on a manufacturer, a brand, an energy.

Large prints were always on the table. It always as. I mean, it is not really bound with the ethical and autonomous approach I dream of. It is just the way I like to see and show my work. And all that times I teach the concept of camera obscura to people, I would have liked for us to be in the camera, so much easier to understand; So powerful !

Camera
Building a human sized camera. Lightweight and that can be taken to pieces (like Abelardo Morell's one (https://www.youtube.com/watch?v=EV-qwEUCWtw)). I'm thinking of a tent like structure made of wooden bars.

Lens
After many searches on internet, I found the APO NIKKOR 1210mm seems to suit my project. The image diagonal/price ratio is my priority. It has to make the biggest image, for the less money. :)

What for
Landscapes mainly. Would love to try long exposures of farm animals also.

Technology
I am really into color photography and I want my setup to be mobile. Direct positive (Type-R) was my first choice, but sadly, Cibachrome is over. Then I found about the Harmann Direct Positive Paper wich develops in cafenol. This is the option I take for now.

I would like to use this thread to asks you all for advices, show you the progress of this project I'm starting and may be long to achieve.

Questions

- Is the 1210mm a good option ? The diagonal is around 1,20m isn't it ? Does it exists other affordable lenses in that kind of ranges ?
- Is there a better place than eBay to buy lenses ?
- Would it work with a simple hole ? What would be the cons and pros of a pin hole ? Is it just about sharpness ?
- For the tent, I'm looking for something lightweight, fully opaque, without plastic or oil in it. Any ideas ?

I'm open for any kind of tips, ideas, artists to discover, so feel free to share, I look forward to read you !

esearing
7-May-2020, 04:43
Refrigerator box roughly 4x4 feet/ 1220mm in the USA, not sure what size a fridge in France would be but there may be other furniture boxes you could use. Tape roll printing paper to moveable wall/easel inside of the box for focus. May need to create a cloth cover to make it opaque and you will likely need a support for the lens. Coat your own paper for faster speeds than enlarging papers.

Pere Casals
7-May-2020, 06:28
Start practice with smaller formats, with focal around 600, a Lomo O-2 600, a cheap Apo Ronar...

You may use simple Variable Contrast paper, use a yellow-green filter to lower contrast. You obtain a paper negative and later you make a contact copy (emulsion side on emulsion side). Regular BW photo paper can also be reverse processed.

Learn all you can about sensitometry, you have to nail your exposures and highlight/shadow depiction: "Beyond the zone system" book, Phil Davis.






- Is the 1210mm a good option ? The diagonal is around 1,20m isn't it ? Does it exists other affordable lenses in that kind of ranges ?



It is an excellent choice.

1210, f/12.5, dialyte, 40º coverage, near 4kg

https://galerie-photo.com/apo-process-nikkors-en.html

Image circle (format diagonal) is 880mm, if focused at infinite, See how it is calculated:

203491

Image circle is the one manufacturer says image is good inside, it may illuminate more than this but quality degradates beyond the Image Circle boundary.

With process lenses image circle may be given for close subject distance, not at infinite. With a close subject you extend bellows to focus, and the same coverage angle gives a larger circle than for infinite focus, be careful with that because circle can be specified for 1:1, not for infinite focus.


More choices: Zeiss Apo-Tessar 900mm/9 , 769€ Ebay now

See this: https://www.angusparkerphoto.com/blog/2015/2/ulf-lens-recommendations-14x17 (ronar, germinar, artar...)





- Is there a better place than eBay to buy lenses ?


It's not about the place, it's about you. You need to know what you want and being patient to find a good opportunity. Ebay is good because you know the seller's reputation, paypay protects you, and you may buy articles that can be returned, but there are other ways.




- Would it work with a simple hole ? What would be the cons and pros of a pin hole ? Is it just about sharpness ?


Of course it will work, your aperture will be small so exposure will be long. With pinhole you have the blurr confusion circle around the hole size, suposing subjet is far, a larger blurr circle if subject is close.

For a 1200mm focal you are to use a 1.5mm hole delivering f/822 . Here it balances optimal diffraction vs hole : https://www.mrpinhole.com/holesize.php

Your image would have a 1.5mm blurr circle.

Pros: you only need a hole, a 1.5 mm one it's easy to make. Holes for smaller formats have to be better machined to do a good job.

Cons: low speed, 1.5mm blur for f= 1200.




- For the tent, I'm looking for something lightweight, fully opaque, without plastic or oil in it. Any ideas ?


Not lightweight but quite convenient:

203492

203493

ic-racer
7-May-2020, 06:29
The largest Harman direct positive paper I see on their website is 11x14. So, as a budget lens you might look for a 210 mm Angulon.

If you want to do 'long focal length' photography, like Feininger, a +1 diopter close up lens has a focal length of 1000mm. You could use that.

Dan Fromm
7-May-2020, 07:39
OP, you are mistaken about the 1210/12.5 Apo Nikkor's image circle. According to Nikon literature and as was pointed out in post #3 above, it covers 40 degrees. This means an image circle of 880 mm at infinity, larger closer up.

Extension -- distance from a lens' rear node, which for process lenses is "not far" from the diaphragm, to the film plane -- when the lens is focused at infinity is the lens' focal length. Greater when focused at closer distances.

Tent and trailer fantasies are all well and good but the lens and film holder really have to be mounted on the same support -- platform, rail, ... -- to keep the film plane perpendicular to the lens' axis.

About buying lenses. If you must have a 1210/12.5 Apo-Nikkor, they turn up more often on yahoo.jp than on ebay.com. I get into yahoo.jp via buyee.jp, a front end with a translator. They're uncommon and expensive. Budget $4k.

Good luck, have fun, visit galerie-photo.info and seek help and advice there.

FrancisF
7-May-2020, 09:45
Sounds like you need a pretty large lens.

Scroll through this link and on the second page you will find a landscape image (the only one I believe) taken with the custom made Fuu-Diing-Chen lens for the ill fated "Dream Community" project

https://www.photrio.com/forum/threads/my-ul-20-x-59-inch-camera-build-in-progress.122544/

Scyg
7-May-2020, 09:51
Start practice with smaller formats, with focal around 600

I'll respectfully disagree here - go right to your intended size. Starting small won't ease the learning curve. The only advantage is material cost, but you'll be buying two sets of optics and building two sets of cameras. Doesn't seem like an efficient way to go about figuring things out.

I may be biased, but I'd recommend going with a pinhole, at least at first, until you've got your process figured out better.


For a 1200mm focal you are to use a 1.5mm hole delivering f/822 . Here it balances optimal diffraction vs hole : https://www.mrpinhole.com/holesize.php

Your image would have a 1.5mm blurr circle.

Pros: you only need a hole, a 1.5 mm one it's easy to make. Holes for smaller formats have to be better machined to do a good job.

Cons: low speed, 1.5mm blur for f= 1200.

All true, but at large print sizes your longer viewing distance makes up for a lot of the softness. It'll never look like something done with a Nikkor, but you'll get a lot fewer problems with DOF and messing with the plane of focus :p .

Pere Casals
7-May-2020, 10:43
I'll respectfully disagree here - go right to your intended size. Starting small won't ease the learning curve. The only advantage is material cost, but you'll be buying two sets of optics and building two sets of cameras. Doesn't seem like an efficient way to go about figuring things out.

Well... not only material cost, building a MF (Monster format) setup may require several design iterations, but YMMV.





I may be biased, but I'd recommend going with a pinhole, at least at first, until you've got your process figured out better.


At 1200mm focal the good pinhole aperture is around f/800, and Type-R paper is ISO 1 to 3. Combination of the two things... OP may use a 3mm hole with that blur and regular photopaper with ISO around 8, which would divide exposure time by 30.




but at large print sizes your longer viewing distance makes up for a lot of the softness. It'll never look like something done with a Nikkor, but you'll get a lot fewer problems with DOF and messing with the plane of focus :p .

If a print has to be sharp at reading distance orat viewing distance this is a personal choice, but that pinhole print would only look sharp from around 3m far, around x10 times the reading distance as it would resolve 0.6 lp/mm with a 1.5mm hole.

Instead if you shot (say) regular 5x7" then you can enlarge a monster print that is totally sharp at reading distance.

Here also YMMV, nothing wrong in crafting that with pinhole, but the Kurt Moser way mentioned by OP is/was a high performance bet, wet plate has amazing resolving power, and the APO-Nikkor 1780mm has to be resolving an impressive IQ for the format, to the point that we would need an strong magnifier (x15) to see the image limits of that directly crafted image...

Scyg
7-May-2020, 11:14
Well... not only material cost, building a MF (Monster format) setup may require several design iterations, but YMMV.

Agreed, though upscaling is a somewhat different process than simple design iteration, and introduces additional variables into the equation. Question of personal choice how you tackle the problem.

Pere Casals
7-May-2020, 11:57
Agreed, though upscaling is a somewhat different process than simple design iteration, and introduces additional variables into the equation. Question of personal choice how you tackle the problem.


in this case uscalling it's easy. We have a tent with probably a vertical Melamine Board working as a projection screen...

Look: no holders...

We throw 3M Re Mount glue on the Melamine Board, hanged from a frame... it can tilt. The frame can swing as it rests on the ground.

After framing we place place a cap on the rear cell and we open red light.

We place the photo paper on the Board and we remove the cap on the lens...

Then we develop inmediatelly inside the tent, or we place the sheet in a tube to be processed at home. But we may want to process test strips in the location to see how good is exposure.


What is upscalling here ?

Well, it is making a 1.2m tray for the media size OP suggested, and locating a 1200mm lens. The nikkor or an APO-Ronar-CL...


The 1200 glass is the big investment... and it may take months or years locating one. Instead we may start with a $150 600mm glass in two weeks, using a regular 38" darkroom plastic tray, $40. Enough to judge if one likes that path and what amount is worth to spend in the 1200mm glass.

goamules
7-May-2020, 12:47
There is a longtime member here that has a camera he told me about the other day. It's big enough to sit inside of, while the exposure is made! Maybe he'll see this and weigh in.

Dan Fromm
7-May-2020, 13:34
Instead we may start with a $150 600mm glass in two weeks, using a regular 38" darkroom plastic tray, $40. Enough to judge if one likes that path and what amount is worth to spend in the 1200mm glass.

Did you purchase a "600mm glass" for $150? If you haven't and are looking at a lens from an aerial camera offered on eBay, look closely and make sure that the seller is offering a complete lens, not one of two cells.

erian
7-May-2020, 13:53
Not light but can be taken to pieces.

203509203512203510203511

I took pictures on 50x60 cm photo paper.

Developed in trays inside the camera.

We dried 760mm Artar (a bit too sharp) and 500mm Tessar (a bit too wide). Because it was a Christmas project in another country then I ran out of time and did not manage to try 800mm Triplet. I think that would have been a good match. I hope to try it when I get back there.

We used just a simple stand for focusing. Worked well. Shutter was just a cardboard taped in place. I used simple timer for measurement. My friend stayed outside of the camera and helped me with development by measuring the time (I did the same for him).

Pere Casals
7-May-2020, 15:16
Did you purchase a "600mm glass" for $150? If you haven't and are looking at a lens from an aerial camera offered on eBay, look closely and make sure that the seller is offering a complete lens, not one of two cells.

I purchased my Lomo O-2 600mm for 35€ several years ago. It was a true bargain, totally new. Now those can be found for around 150€.

I have to rate its lp/mm performance, that may be surprisingly good, I've 8x10" night shot where it depicts pretty well a cigarette end at 180m, so I'm curious. You told me time ago that those lenses were wide open rated, so they may be better than catalog says.

Drew Wiley
7-May-2020, 15:29
Dan and Pere - Nikon's Apo Nikkor image circle specs are geared to apo dot color repro standards @ f22, which are far more stringent than needed for general photographic applications. For all practical purposes, the real world image circle is going to be much bigger, especially stopped further down as would normally be the case. Numerous portable cameras this size have been made, and even much bigger. Searches of past threads might be beneficial. Otherwise, Type R color paper is extinct and never was the same thing as Cibachrome, which is now also gone. But it is possible to still make a reversal positive color print using current chromogenic papers like Fuji Crystal Archive, but with a concocted developer rather than standard RA4. I can't vouch for the visual quality of the result or print permanence; but it is being done by a few people.

tiphaine
7-May-2020, 23:34
First of all, Thank you all for the fasts replies, I wasn’t expecting that much ! Really great to see the interest you have in such project.

Originally, I bought a van for my project, and as time went by, I started to want a « greener » approach. At least one without a car. You’re going to laugh, I plan to move with donkeys ! But it is not my first concern, I might start shooting right outside my home to practice.

The pinhole might be a good start, I can practice and adjust the tent right now and search a lens at the same time. I wasn’t expecting such f/ though ! f/800 at iso 3-5, it might take some time. About the sharpness : I need a lens. I like my pictures to be as detailed as it can be. I like to dive into sharp large prints. The Lomo option is to be considered too.

For the paper, I’ve found a 127cmx15m roll of Hartmann paper. As you would expect, price is not low. That and the price of the lens will be two major concerns. I once made some photographic paper when I was in school, might consider that option too. Or asks Harman for a partnership :p

For the lens mount, I’m thinking of making a custom swivel, that can go right/left and up/down, mounted on a tripod with adjustable legs for the horizon.

For the paper mount, something similar, that can be move and rotate easily. As I’ll be inside the camera, it may be easier to adjust focal plane and avoid mistakes. I’m convincing myself here. I can’t use melanin board alas, too big and heavy to move. Maybe a custom foldable wood plane. I don’t know… will look into that !

For developing, Pere Casals read in my mind. Was indeed thinking of travelling light : Big papers pre-cut in individuals carton rolls, a little bit of developer and little papers for testing on locations. Is my photography safe if it is in the dark ? Can it be stored before being develops without prejudice ?
Thanks Drew, I mingled the Type-R and the Cibachrome sorry, and for the RA4, nothing I’ve seen (on YouTube though) convinced me. It seems complex and results average. I think I made my grief on color process on this on particular project. I'm ok with the cafenol prints I've seen.

Thanks FrancisF for the links, that is exactly that kind of size I’m looking for ! The link to the specific image : https://www.photrio.com/forum/attachments/twlns2-png.245236/

Thanks for the Yahoo.jp and buy.jp tips. Nice project Erian !

Here are some 3D renders the model I designed quickly for the tent. Wood and metal clips. I would add strings and tents pegs all around to tighten it.

203543
Donkeys !

203544

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Havoc
8-May-2020, 00:52
My project
No electricity, no photography. No oil, no photography. No plastic, no photography. One night, as I was looking for sleep, I wondered why there isn't it already a "green" photography. I mean, today all is rebranded with an ecological bias. There will be a day soon that some big brand come to you with a greenwhashed camera and our conscience will be happy.

Ok, perhaps a silly idea, but if you want it totally "green" have you thought of photosensitive organisms? There has been research around that years ago. I read about this when reading about the history of the invention of recordable CD technology.

Rayt
8-May-2020, 06:08
The only green all natural photography I can think of is the Shroud of Turin and literally it is human sized. Need to find a cave though and a huge boulder.

Randy
8-May-2020, 14:38
Several years ago I purchased a lens element, a positive meniscus lens from Surplus Shed (https://www.surplusshed.com/) here in the US. It is about 145mm in diameter and has a focal length of about 3 meters. It is very light, only about 6-7mm thick. I made a frame from black foam-core and reduced the aperture (cut a circle in a sheet of black art paper) of about 100mm, so I think this comes out to be a 3 meter f/l lens with a f/27 aperture. I would think, if you could get your hands on such a thing, it would serve your purpose. I don't think I paid more than about $12 US for this glass. I have no idea what the initial purpose for this glass was. My intention was for a room sized camera obscura.

Jim Jones
9-May-2020, 16:33
[QUOTE=Pere Casals;1550495]

. . . Of course it will work, your aperture will be small so exposure will be long. With pinhole you have the blurr confusion circle around the hole size, suposing subjet is far, a larger blurr circle if subject is close.

For a 1200mm focal you are to use a 1.5mm hole delivering f/822 . Here it balances optimal diffraction vs hole : https://www.mrpinhole.com/holesize.php

Your image would have a 1.5mm blurr circle.

Pros: you only need a hole, a 1.5 mm one it's easy to make. Holes for smaller formats have to be better machined to do a good job.

Cons: low speed, 1.5mm blur for f= 1200. . . .

There are many recommendations for the correct diameter of any focal length in pinhole photography, often based more on theory or poor advice rather than on hands-on experience. Based on my experience, the optimum pinhole diameter for a 1200mm focal length would be about 1.3mm. This would resolve about 1 line pair/mm where the on-axis blur circle from geometric optics and diffraction phenomena are about equal. At that point, image blur is less than predicted by both geometry and diffraction. As the pinhole diameter increases, geometry determines image blur. As the pinhole diameter becomes smaller, image blur increases in a less predictable manner due to diffraction. Also, interpreting image blur of standard test charts varies among different people.

Wide angle pinhole photography brings up other factors which affect one's choice of pinhole diameter. As the angle of coverage increases, some photographers may wish to slightly increase the pinhole diameter to improve sharpness towards the edges of the image despite enlarging the central image blur. A pinhole image has negligible drop-off in sharpness up to 20 degrees from the pinhole axis. By 40 degrees there is little loss In radial sharpness, but about 35% in tangential sharpness. By 50 degrees the radial sharpness has dropped of noticeably and the tangential sharpness by 60%. This demonstrates that wide angle pinhole cameras show substantial astigmatism in addition to the distortion that all wide angle cameras have. If we move in close with a well-designed wide angle pinhole camera while maintaining the same image size, the image blur decrease. That is one way of improving pinhole image sharpness if the subject permits.

Much of this information is based on 40-year-old photography. It is based on rather casual photography instead of the more rigorous work that would be more valuable to researchers. I don't even have a darkroom now. If the more inventive photographers on this site unite to pool their findings, we may become the new center for pinhole photography.

Tin Can
10-May-2020, 07:29
[QUOTE=Pere Casals;1550495]

. . . Of course it will work, your aperture will be small so exposure will be long. With pinhole you have the blurr confusion circle around the hole size, suposing subjet is far, a larger blurr circle if subject is close.

For a 1200mm focal you are to use a 1.5mm hole delivering f/822 . Here it balances optimal diffraction vs hole : https://www.mrpinhole.com/holesize.php

Your image would have a 1.5mm blurr circle.

Pros: you only need a hole, a 1.5 mm one it's easy to make. Holes for smaller formats have to be better machined to do a good job.

Cons: low speed, 1.5mm blur for f= 1200. . . .

There are many recommendations for the correct diameter of any focal length in pinhole photography, often based more on theory or poor advice rather than on hands-on experience. Based on my experience, the optimum pinhole diameter for a 1200mm focal length would be about 1.3mm. This would resolve about 1 line pair/mm where the on-axis blur circle from geometric optics and diffraction phenomena are about equal. At that point, image blur is less than predicted by both geometry and diffraction. As the pinhole diameter increases, geometry determines image blur. As the pinhole diameter becomes smaller, image blur increases in a less predictable manner due to diffraction. Also, interpreting image blur of standard test charts varies among different people.

Wide angle pinhole photography brings up other factors which affect one's choice of pinhole diameter. As the angle of coverage increases, some photographers may wish to slightly increase the pinhole diameter to improve sharpness towards the edges of the image despite enlarging the central image blur. A pinhole image has negligible drop-off in sharpness up to 20 degrees from the pinhole axis. By 40 degrees there is little loss In radial sharpness, but about 35% in tangential sharpness. By 50 degrees the radial sharpness has dropped of noticeably and the tangential sharpness by 60%. This demonstrates that wide angle pinhole cameras show substantial astigmatism in addition to the distortion that all wide angle cameras have. If we move in close with a well-designed wide angle pinhole camera while maintaining the same image size, the image blur decrease. That is one way of improving pinhole image sharpness if the subject permits.

Much of this information is based on 40-year-old photography. It is based on rather casual photography instead of the more rigorous work that would be more valuable to researchers. I don't even have a darkroom now. If the more inventive photographers on this site unite to pool their findings, we may become the new center for pinhole photography.

Very good info and new to me

Thank you

Pere Casals
10-May-2020, 10:37
[QUOTE=Pere Casals;1550495] Based on my experience, the optimum pinhole diameter for a 1200mm focal length would be about 1.3mm. This would resolve about 1 line pair/mm where the on-axis blur circle from geometric optics and diffraction phenomena are about equal. At that point, image blur is less than predicted by both geometry and diffraction.

Jim, clearly the geometric blur circle is uniform and exactly equal to the the pin size for distant subjects, when taken rays are parallel (distant subject) the pin circle is exactly equal to the projected circle...

203600
(hole painted way larger than ideal to show the effect)

but the blurr effect in the resolving power is lower, because when adding all circles generated by a white line (say vertical lines patern) adds more overlaping light power in the vertical direction than in the horizontal direction.

I guess this may explain the difference between blur circle size and the better than expected resolving power...

I guess that the ideal hole depends also in how well made it is, what subject distance optimized, what (angle) format size vs focal length...

If your ideal circle is 1.3mm instead what the calculator says... then of course your hole is of high quality, generating a lower diffraction from a perfectly smooth bore.


For the moment my experience is only with paper negatives, mostly at around 240mm focal for 5x7, but I plan to play with larger formats. Clearly the larger the hole the easier to make an efficient one !!

pvan93
19-Jun-2020, 03:48
You might try finding a copy of ‘Primative Photography’. Has info on building simple lens. Tin Can has good idea for long focus single element lens. Another possibility would be a Nikon 52mm #0 closeup lens (0.7 doplier, 1400mm), someone else also made a 0.5 doplier closeup lens. Any of these can be found for $25- $35 US. Could work for developing your concept.

tiphaine
19-Jun-2020, 22:26
You might try finding a copy of ‘Primative Photography’ I'm looking into it right now and it looks really cool to have ! Thanks for the reference !

tiphaine
6-Sep-2020, 06:48
You might try finding a copy of ‘Primative Photography’. Has info on building simple lens. Tin Can has good idea for long focus single element lens. Another possibility would be a Nikon 52mm #0 closeup lens (0.7 doplier, 1400mm), someone else also made a 0.5 doplier closeup lens. Any of these can be found for $25- $35 US. Could work for developing your concept.

Were you talking about that ? https://www.bhphotovideo.com/c/product/801834248-USE/nikon_2732_52mm_0_close_up_lens.html

tiphaine
6-Sep-2020, 08:35
Hi all,

it's been a while so I figured I would give that thread an update ! Here is were I am :

- I ordered "Primitive Photography"
- Still in search for a big lens; I've found an APO-RONAR 1000mm on ebay. The seller is in France but the price is a bit too high (2800€)
- I talked to Kurt Moser / Lightcatcher about my project.
- I looked the simple Nikon 52mm #0 but it was hard to find. I stumbled upon the Bonfoton website and ordered one of their lens for 41€. Will do the firsts test with it at home. Cheap and convenient ! I might do all my project with it if it's sharp enough (even if I really doubt so).

Hope you're all well,
Tiphaine

Dan Fromm
6-Sep-2020, 10:00
https://bonfoton.com/

Jim Noel
7-Sep-2020, 18:36
I don't believe a #0 is long enough to do what you wish. It is only one meter If you decide it is for you, let me know via PM, I may have one and if so it would not cost you very much.

pvan93
9-Sep-2020, 06:12
Yep, that’s it.
Trying to find the other two examples of close focus dopliers. One was +0.5 and the other was +0.25. All three were to help early zoom lens focus closer. Nikons +0.7 was designed for their 43-86 zoom. Looking around in old boxes for the other two.
Bought the +0.5 a few months ago for $25-35. Not sure how sharp it would be. But it was made by a name brand lens co. And way easier to find and less costly than a Apo Nikkor. Will post when I find it.

pvan93
9-Sep-2020, 06:26
Just looked on EBay. Try the seller ‘Cambridgephoto’. Looks like they’re selling a +0.5 and +0.25 vivitar brand. You want to confirm those focal lengths before buying. Easy to tape on a window and check sharpness for your project.

Tin Can
9-Sep-2020, 07:10
Look here, some big things

https://www.bhphotovideo.com/c/search?Ntt=%2B1%20diopter&N=0&InitialSearch=yes&sts=ma

Tin Can
9-Sep-2020, 07:42
I want to try a trailer cam

Just bought two 36 mm diameter 4000 mm positive meniscus coated, part # L14816 from surplus shed for $16 delivered

The trailer is 14' straight and 17' with nose

I am in it every day, already made dark slides for the 2 windows

no time to waste

Great thread!

diversey
9-Sep-2020, 08:23
I am also interested in this human sized camera. I have a 48" (1219mm) lens, a 20x24" contact frame and a box of 20x24 photo paper. I need find a big camera box/tent and a print drum.

Tin Can
9-Sep-2020, 08:27
When I do big enlargements I test center and corners with 5X7 RC paper

tiphaine
20-Mar-2024, 13:13
Hi all,

Much has happened since then but the project is still in progress !

Here is an update of it :


PAST :

- I made a wooden pinhole camera to test the Harman Positive Paper. I lost the results in a move between houses.
- I bought a Rodenstock APO-Ronar 1070mm F/14 from someone living 1 hour away from me. I was able to see the beast for real before buying, so lucky !
- For a long time I stored it because there wasn't any mount on it so I couldn't put it on a tripod.
- I began to work with cows, and then horses too. Not ready to guide a pair of it however.


PRESENT :

- Recently I made a custom piece so I can screw a quick release plate on it. See pics below. That took me so long but it’s done and I'm so happy to be able to put my lens on a tripod.
- I finally made some first camera obscura tests. Here are the first results so far.
- Day 1, my girlfriend and I were so amazed and this was all about excitement and opening a new world of creative possibilities !
- Day 2, I was wondering about the minimal distance of focus. I put the lens instead of my front door, put a drying rack right in front of it and hung a tea cup on it. The object had to be small and shiny so I could see it easily and still see the background behind it. The wind kept making it sway, so that was nice to watch ! The farest wall from the lens is 7,3m away. To have the cup in focus, I had to put it 1,25m away from the lens. It was so huge, yet the quality was wow !
After that I decided to play with depth of field. I got back into our bedroom and tried to close the diaphragm to see the DOF changing. Then I tilt the focal plan (a piece of plywood for now) here and there to see changes. I did a Scheimpflung attempt so the tree line in the background was sharp. And an anti-Scheimpflug to make only the electric post in focus. The setup is still installed, amazing to see the cloud come and go.


FUTURE :

- I want to redo some tests with the direct photo paper from harman. I know that it is selling a 1,27mx15,0m roll of it so I know I would be able to scale up if I’m going with that solution.
- I'm still looking for a color solution though. Look at that blue sky and those yellowish fields !
- I will transform my van into a camera. I suppose it will be a first step toward a solution powered by real horses ! I want to make a system in my van to slide, rotate and tilt a plane on which I’ll magnetize the photo paper. My idea is to put the lens in the back of the van. Maybe be able to process the pictures in there too...


QUESTIONS :
- Is there a linear relation between distance from lens to object and from lens to focus plane ? Today my object was placed 1,25m from the lens and the focus was 7,3m behind the lens. Can I use that ratio to calculate future space needed for another object. Would be super practical to know where to position myself on the field !

- I’ll probably need a shutter, even if exposure time might be pretty long most of the time, so maybe you know a hack to DIY that ? 3D print ?

PICTURES :

248042248043248044248045248053248050248052248054248055248057

tiphaine
20-Mar-2024, 13:28
248061248062248063248064248065248066248070248068248069

ic-racer
20-Mar-2024, 16:02
1/p + 1/q = 1/f

tiphaine
21-Mar-2024, 04:21
1/p + 1/q = 1/f
Thank you for pointing it out. I had a bit of a hard time to understood it but I have finally got it. I made a template on a Google Sheet so I'll just have to input the distance of my subject to get an idea of the space I need behind the lens. I suppose it will be useful at first.
In my van I would be able to shoot as close as roughly 2.3m. Pretty nice portraits to come !

ic-racer
21-Mar-2024, 14:53
I wasn't sure if you had encountered the equation before, the 'thin lens equation'

http://hyperphysics.phy-astr.gsu.edu/hbase/geoopt/lenseq.html