Compressed perspective on 4x5" - 800mm?

[Patrik Roseen]

Hello, I have seen photographs by Andreas Feninger where he was using a homebuilt 4x5" camera with a long telephoto-lens and I have really come to like the compressed perspective in his photographs, where everything comes closer front-to-back.

So, I'm thinking of building something myself using a large lens in the area of 800-1000mm and basically only use it for infinity distance.

800mm on 4x5 corresponds to something like 250mm in 35-format.
Question: Will the photograph in 4x5 look as compressed as a 250mm or as a 800mm on 35-format?
/Thank you

[GPS]

When you speak about compression you mean the spacial compression, I read. Therefore the look will be in this sens like 800 on 35mm format.
By the way, I have constructed such a camera (with 800mm lens) and I use it a lot (for 6x12cm format). The setup is so quick that it allows me to react on meteorological phenomena in far mountains. An excellent idea to build your own!

[Patrik Roseen]

When you speak about compression you mean the spacial compression, I read. Therefore the look will be in this sens like 800 on 35mm format.

Yes, spacial compression might be the expression for this...it's when the perceived distance between far and near objects disappear.


By the way, I have constructed such a camera (with 800mm lens) and I use it a lot (for 6x12cm format). The setup is so quick that it allows me to react on meteorological phenomena in far mountains. An excellent idea to build your own!

GPS, I would be interested in knowing more about your setup. Andreas Feininger's camera looked very shaky and it required two tripods for stability. Which lens are you using?

I am thinking to not use bellows...but rather a fixed box like Feininger did. The image circle from this size of lens might be huge so I will need to reduce internal flare (possibly attaching a cone on the rear cell?) - any suggestions?

Comments?

[Mark Sampson]

You might look at the work of the late German photographer Reinhart Wolf. His book "New York" consists of telephoto views of the tops of skyscrapers at sunrise, and the credits section shows him with a huge Sinar 8x10 setup; two tripods, many bellows extensions, and perhaps a 1200mm lens. I have another book of his featuring castles in Spain that looks to have been done similarly.
And a guess on my part- it might be easiest to control camera flare with a compendium lens hood, rather than inside the camera.

[Patrik Roseen]

You might look at the work of the late German photographer Reinhart Wolf. His book "New York" consists of telephoto views of the tops of skyscrapers at sunrise, and the credits section shows him with a huge Sinar 8x10 setup; two tripods, many bellows extensions, and perhaps a 1200mm lens. I have another book of his featuring castles in Spain that looks to have been done similarly.
And a guess on my part- it might be easiest to control camera flare with a compendium lens hood, rather than inside the camera.

Thanks for the suggestion Mark! I will try to find this book.

Yes that's right? using a compendium on the outside would actually make the image circle smaller...I did not think of that. Thanks!

[Jim Jones]

. . . And a guess on my part- it might be easiest to control camera flare with a compendium lens hood, rather than inside the camera.

On a camera with just one long lens, the most practical and efficient lens hood might be one fabricated from light metal, mat board, or whatever is handy. It can be designed to block almost all light from outside the image area. With long lenses, baffling inside the camera body is more efficient than black paint.

[GPS]

Patrik, my camera is built with the 800mm Nikon lens. It is a construction made from aluminum (aluminium if you prefer the British spelling but the result is the same...) angles (profiles). Very sturdy and relatively light. No belows, I used black leather (you can use a black plastic sheet too, I have other constructions with it) that envelops the construction inside (looking like the Eiffel tower but not a cone) and is sealed at both ends with flat aluminum pieces screwed to the body. It makes it much easier to handle than long belows. There is a handle on the top of the camera (attention to the centre of gravity!) so that it is easy to put on the tripod. And yes, I use 2 tripods for stability - far the best solution. It takes just about a 1/2 min. to put up the second tripod. The camera has 2 tripods screws (obviously). The inner aluminum angles serve as light buffles (all the interior is also blackened with a paint). Nothing will move 2 tripods, not even VERY strong winds. I made my own lens shade, very effective. The whole setup is a blaze to use. I often use it for sunrise photography (green flashes etc.) The demon is in the facility of its use... No focusing under black cloth, forget that part and use it as a point & shoot on a tripod (well, 2 of them...) Cheers!

[Jon Shiu]

Hello, I have seen photographs by Andreas Feninger where he was using a homebuilt 4x5" camera with a long telephoto-lens and I have really come to like the compressed perspective in his photographs, where everything comes closer front-to-back.

So, I'm thinking of building something myself using a large lens in the area of 800-1000mm and basically only use it for infinity distance.

800mm on 4x5 corresponds to something like 250mm in 35-format.
Question: Will the photograph in 4x5 look as compressed as a 250mm or as a 800mm on 35-format?
/Thank you
Hello, the perspective is due to the distance from the subjects, so you could use a shorter lens such as 300mm on 4x5 and then crop to get same perspective as an 800mm lens (on 4x5). Just an option to try the shots without having to build.

Jon

[GPS]

Jon, you didn't get it, I'm afraid. It's just the opposite, think over it a little bit... :-)

[Jon Shiu]

Jon, you didn't get it, I'm afraid. It's just the opposite, think over it a little bit... :-)
Yes, I didn't read the question carefully.

If you use a 800 mm lens on a 4x5 and crop it down to a 35mm size film, you will get exactly the same picture as if you used an 800mm lens on a 35mm camera (taken from the same vantage point). I hope that explanation helps him with the concept of perspective.

Jon

[Jim Noel]

800mm on a 4x5 will not come close to the compression of space achieved by Feininger. His focal length was 5 feet.

When these images first appeared in the literature, particularly Life magazine, my high school frineds and I mimiced him. We used salvaged single lens elements and combined them to get the 5 foot focal length. These were then mounted in heavy mailing tubes which would slide one inside the other for focusing. This lens was mounted on one tripod and my 4x5 graflex on another. Our first images were of the dome of the Tennessee State Capital from approximately 8 miles at night. It worked. Beautiful compression.

I have been having fun ever since. If photography is not fun, why do it. Experiment, you never know what you will come up with.

Jim

[Patrik Roseen]

Thanks GPS, I'm trying to visualize your description but I do not fully succeed...do you have a photo of the camera you could share?


800mm on a 4x5 will not come close to the compression of space achieved by Feininger. His focal length was 5 feet.
Jim

Jim, I was afraid of that, hence my initial question. 5 feet is very looong.

Here is a photograph of the camera Feininger was using in Stockholm in the 1930's.
In this photo there is only one tripod...I was trying to work out the length from looking at the camera back. I guess this picture does not show the camera fully extended, assuming the sections are each as long as the left section.
EDIT!! The book states that Fenninger was experimenting with telephotocameras during his years in Stockholm...it could be that the one pictured here use 6,5x9cm plates and that this particular lens is a Meyer-Aristostigmat 1:12,5f/30cm portrait lens...but again the text is not very clear on this as it also mentions another camera in the same paragraph.

[GPS]

I don't use scanner so I can't send the pictures I have of this camera... Think of it as a rectangular skeleton made of profiled aluminum that holds the lens and film standards apart. It looks very much like the Feininger camera you show on the picture. You say it has 1 tripod only - true, but he uses a 2nd leg to support the camera back. This solution is much less stable than 2 tripods.

[GPS]

By the way, what lens did Feininger use??

[Patrik Roseen]

By the way, what lens did Feininger use??

GPS, I have edited the information in my previous post...I hope Jim can answer your question.

[GPS]

Sorry Patrik, I overlooked the info, but the camera on the picture is surely longer than 30 cm - and surely not long 1.5 ft if it is a 6,5x9 cm format. I'm not avare of a lens with 1,5 ft focal length, hence my curiosity.

[Patrik Roseen]

I found the following information on the web
...fotografia/feininger/ecronos.htm (http://www.emmedici.com/hobbies/fotografia/feininger/ecronos.htm)

1936-1939 He changes from architecture to photography working in Sweden and realizing photos of architectures and industries. He constructs his first camera; focal length 70cm on a 6 1/2 x 9 cm film.

GPS, this is probably what is on this picture, as you say it does not look like a 300mm

1941 Leaves the Black Star and becomes a photographer of Life with a minimum wage. He constructs his second camera: focal length 100 cm on a 4 x 5 film.

So it's in the range of 1000mm and as Jim points out maybe he used even longer ones...

[GPS]

On the other hand, if Jim is right with 1,5 ft then 1200mm Nikon is not far away from it - you could try with that length. I decided for the 800mm Nikon basicaly because of a smaller weight and I'm glad I did not choose the bigger Nikon as this camera, although light in itself weighs with its special case (aluminum too) a little under 10 kg just enough to be carried about 3-400m from a car.

[GPS]

My second camera of this kind was a shorter variant with a 600mm Fuji lens and 6x9cm format, using the excellent Mamiya Press RFH. It's of course lighter than its bigger brother and, interestingly enough, has the same horizontal field of view. It gets used more often, principally because even lighter. 2 tripods this one too. Out of my window I use it for meteorology pictures (optical phenomena in clouds) and some nice distant scenes changing with weather and year seasons.

[Patrik Roseen]

...If you use a 800 mm lens on a 4x5 and crop it down to a 35mm size film, you will get exactly the same picture as if you used an 800mm lens on a 35mm camera (taken from the same vantage point). I hope that explanation helps him with the concept of perspective.

Jon
Thanks for the explanation Jon...it helped.

And I guess the following is true as well, i.e. if I from the same location use 800mm on 4x5" and 250mm on a 35mm-camera and then enlarge the 35mm-negative to 4x5" size, the two 4x5" negatives would be identical, right?

[Sheldon N]

Thanks for the explanation Jon...it helped.

And I guess the following is true as well, i.e. if I from the same location use 800mm on 4x5" and 250mm on a 35mm-camera and then enlarge the 35mm-negative to 4x5" size, the two 4x5" negatives would be identical, right?

Close, but not exactly, probably closer to 225mm. It depends on how you account for the aspect ratio differences. If you think of it as cropping the 35mm frame to a 4x5 aspect ratio (effectively using the short side for comparison) then it's more like a 200mm lens (4x multiplier). If you think of it as using the long side for comparison, allowing the 4x5 to have more coverage on the short side, then it's like a 240mm (~3.3x multiplier). If you compromise and use the diagonal coverage as the comparison point, then it's more like a 225mm lens (3.55x multiplier).

To me, I've always thought that an 8x10 or 11x14 print was the final result, so I always pictured 35mm as a format that needed to be cropped a little on the ends. When working that way, you always end up needing a wider lens than you would otherwise. For that reason, I've settled on a mutliplier of 3.6 to 3.75 when I want to match up the effective focal lengths of 35mm and 4x5.

[Leonard Evens]

I agree with Sheldon's analysis with respect to equivalent focal lengths. But it should be noted that his calculation is based on approximations that apply only for relatively distant objects. For portraiture, or even more for close-up photography, the calculation is a bit more involved, and the answer depends in part of the focal length. This was the topic of a previous rather long discussion of perspective in portraiture.

The whole issue of compression is, I think, interesting. I've tried to analyze this, and I wonder if anyone agrees with my tentative conclusions.

It is possible to show that the ratio of magnifications, IN THE FILM PLANE, of subjects at different distances is just the ratio of the subject distances. Thus, if a subject is moved twice as far away, its image, with no refocussing, will be one half of what it was. (This assumes you are operating in the DOF region and that no tilts or swings are used.) This is not dependent on focal length. So why does the image produced with a longer focal length lens look more 'compressed'. I think this must be an artifact of the way the visual system functions. The brain interprets the magnfied objects as being closer to the eye, so it also interprets the distance between two objects which are at different distances to be smaller than it is. Suppose for example, you see two people of the same height at distances 75 and 100 meters. The image of the further person will be 3/4 the size of that of the nearer person, and that will remain true whether you look at it normally or through a telescope. But in the case of the telpscope, it might appear as if the people are at 7.5 ant 10 meters respectively. Since you know that they are actually something like 25 meters apart, a considerable separation, since they now appear to be only 2.5 meters apart, your brain interpets this as a compression of the distance between them.

The question does remain, however, as to why an image produced by a long lens of a scene you've never seen looks compressed. I think this must be because the scene contains visual clues which allows your brain to know the subjects are in fact at some considerable distance or which allow your bisual system to estimate the true distance bwtween the subjects. These might involve change in angular seprations, for example. Size constancy, a feature of the visual system which makes comparable images at different distance look about the same size, may also play a role.


On the basis of this analysis, we may quantify the compression factor as that resulting from switching from a normal lens to a long lens. For reatively distant subjects, this will be close to the ratio of the focal lengths. For nearer objects, where the primary subject distance may be not too much larger than the focal length of the longer lens, you have to incorporate an additional multiplier which depends on the subject distance and the two focal lengths.

[GPS]

[QUOTE=Patrik Roseen

And I guess the following is true as well, i.e. if I from the same location use 800mm on 4x5" and 250mm on a 35mm-camera and then enlarge the 35mm-negative to 4x5" size, the two 4x5" negatives would be identical, right?[/QUOTE]

That's right. Perspective is a highly tricky thing. As a rule, if we alter the focal length at the same view point we only change the the image size (which then can be altered by magnifying it), not the perspective. If we alter the viewpoint and the focal length simultaneously as a result we also change the perspective. Leslie Stroebel in his View Camera Technique nevertheless correctly states the focal length length of the taking lens has an effect on the apparent perspective (as opposed to the linear perspective) in the picture even if the viewpoint is the same! Those are tricky things...

[Patrik Roseen]

Leonard, is it possible to state it like this.

When using a normal lens...the angle of view is so that the relative size of items in the covered scenery is the same as in the picture projected on the film. We do not have any problems to understand this kind of picture.

When using a wideangle lens...everything in the scenery will have to be made smaller for everything to fit on the film...meaning that the further away an item is it will be made relatively smaller than a closer object. We will therefor interpret the picture as looking at something where everything is stretched out into infinity.

When using a telephoto lens with a much smaller angle of view the objects further away will not suffer too much from having to fit into the film...thus they look relatively larger than they really are...which lead us to think that they are closer than in reality.
In your example the person standing 25m further away will become relatively 'larger' (will not shrink as much?) than the person in the front, thus we interpret this person as being closer than s/he is.

So in this case the 'compression effect' has to do with the angle of view when projecting the image on the film. And this would be the reason why the 800mm on 4x5" is the same as the 250mm (225) on 35mm-film ...since they have the same angle of view for the chosen film formats.

Leonard, what do you say?

[David A. Goldfarb]

I think viewing distance must play a role in these perspective effects. In theory, a wideangle image should look "normal" when viewed at a very close distance, and I suppose an image made with a long lens will also look "normal" when viewed at a great distance, but if we look at all images as 8x10" prints at arm's length, then a wide image looks expanded, an image made with a normal lens looks "normal," and an image made with a long lens looks compressed.

[Leonard Evens]

David's last comment is of course completely correct. I think Patrik's explanation in essence refers to the same issue. My analysis can be looked at as simply a way to spell out just why the shift in the viewing point for the print yields an apparent compression. But there may be more to it. For example, the compression effect is quite strong when using a telescope or binoculars. There may be an explanation of the latter fact based on viewing point, but off hand I don't see what it might be.

[GPS]

For example, the compression effect is quite strong when using a telescope or binoculars. There may be an explanation of the latter fact based on viewing point, but off hand I don't see what it might be.

This compression effect has to do with the limited field of view that fools the brain to "see" without spacial relations. Such is the explanation for the apparent perspective.

[GPS]

So, in the end, did you decide to construct the camera?

[Patrik Roseen]

So, in the end, did you decide to construct the camera?

Yes I am still very interested and intend to construct one. However, I need to find that large lens ... with a good price...Since I will not use a ground glass for focusing, a slow lens will not be a problem.

So, which lenses should I be looking for in the range of 800-1200mm, which will not be too heavy to carry around (for 4x5")?

BTW , I received a very interesting mail from a person on this forum showing a very clever solution for a long camera...Please post your pictures here, I guess more people would be interested.

[GPS]

One nice day I will maybe buy a scanner (personnelly, I don't need it, or so I think)... As for the lenses, if you don't want to invest to long Nikons, I would use long process lenses (Ronar, Nikon etc.) It's only after you have built it you will see all its possibilities. If you are interested in some special info contact me off the net. Cheers.

[Dan Fromm]

I've been bugging Patrik via e-mail about his silliness. He's responded to the effect that I should show mine off. I've done it before, believe that all of you have seen it already, but for those who haven't here's a link to a link of my 2x3 tandem camera. The same idea would work with larger cameras.

Go here http://www.apug.org/forums/showthread.php?t=18930&page=1&pp=10 , look for a short (!) post from me towards the bottom of the page, click on the link in it.

One limitation -- pay attention, Patrik -- of my approach is that the rear camera's lens throat/front standard can limit coverage. My rig covers 2x3 just fine with a 480 at infinity and will focus it to 1:10 without vignetting. I've convinced myself that the next version with a bellows for a 35 mm camera in front of the front camera will just cover nominal 6x6 at infinity with a 600, won't focus much closer without vignetting. Surprisingly, the limiting obstruction is the rear camera's front standard, not the Copal 1 and narrow tubes etc. in front of the front camera. If you do the analysis, you'll see that unlike the usual case, where the lens' coverage is limiting, with a tandem like mine focusing closer makes vignetting worse.

About practicalities. I now have five lenses that will focus on the tandem. 420 and 480 Apo Nikkors; 300 and 360 Apo Saphir; 450 Lomo RF-5. The longest one I use much is the 360. I'm just, um, seeing too wide for anything longer to make sense in the situations I've found myself. Patrik wants to go to somewhere around 6x the normal focal length. I've found 5x too long nearly all of the time. Time, I guess, to, um, narrow my focus.

Cheers,

Dan

[Patrik Roseen]

I have finally found and bought a lense off ebay for this project on 4x5".
I settled for an Apo-ronar L f9/600mm won at 64 Euro, which I find reasonable.

Still waiting for the lens to arrive from Germany, I now realise that I have no idea of the size and weight of it...which is a pity since I want to get started constructing the camera. Any suggestions?

I could use your help to decide a few issues regarding the design of the camera.
My original idea was to make a stiff box, with the lens set for infinity, using no groundglass - only a simple attachment for the 4x5" filmholder.

With a size of 600mm I am now bugged with second thoughts:

1) Should I construct the camera to also take an 8x10" holder as well as 4x5" using a homebuilt reducing back
2) Is there any use include possibilities for focusing using this lens (600mm), if I do not at the same time prepare for movements?

3) Or should I simply go for my original thoughts, with 4x5" only etc..?

[GPS]

Personal tastes are different - I would go for the original 4x5 only, fixed focus at infinity (not the hyperf. distance). For the simple reason that you will use it more as it is much easier to deploy, less weight = more practical. But how do you want to get rid of the gg? You cannot have a precise viewfinder for a 600mm lens. Don't forget that you'll need some case for it too = more weight again if you build it for 8x10.

[Dan Fromm]

Patrik, the 600/9 L I sold earlier this year weighed more than 3 kg. I gave up on it because of weight. Is yours as heavy?

There's no reason why focusing requires movements. Whether you make a camera with movements depends on how ambitious you are.

If you're going to shoot subjects that aren't distant, I fear you'll need to be able to focus.

Have you thought about a shutter?

4x5? 8x10? 8x10 with reducing back? Its your aching back and your mechanical/carpentry skills. From my narrow parochial perspective they are all very bad.

Cheers,

Dan

[Jeffrey Sipress]

Jon is absolutely correct. You can go through all the calculations and 'standing height' cases you want, but perspective (and the 'compression' or 'wide angle' phenomenon it creates) is ONLY determined by subject to camera distance. Has nothing to do with lenses at all! Just use your eyes and brain to see it's true.

[Patrik Roseen]

Hmmmm? 3kg!

Dan, do you remember the size of it? I have searched this forum for the apo-ronar and there seems to be different ideas about the characteristics of this lens.

With such a heavy lens I am thinking of attaching the tripod close to the lens in the front. If I do choose to have focusing it would be by moving the back (with a groundglass ofcourse).

I thought not to use a shutter with this lens, rather the 'hat trick' stopping down to f32-f45 for DOF.

I have a very skilled friend who will assist me building it so that should not be too much of a problem once we figure out what it should look like. I sense I should be quiet about this project until I can show a picture it has produced ;)

[Patrik Roseen]

The Apo-ronar f9/600mm lens arrived today in very good condition from Germany.

Dan, was right, this is a heavy monster which adds about 3kg to my weight when standing on the scale! The barrel is brass. And the retaining ring alone (copper?) weighs a few hundred grams. But I will not let this disappoint me.

Reading more about Feininger, I have learned that he used a 28" lens (a french barrel portrait lens) while working in Stockholm in the 1930s so the APO-RONAR is pretty close with its 24".


Now it's a matter of having focus adjustments or staying with a fixed focus to start with.

GPS mentions fixed focus at infinity and not the hyperfocal distance.

Are there any suggestions for at which distance infinity kicks in, i.e. distance from the lens. Knowing that I get 2/3 resp 1/3 DOF in either direction around this point, what would you suggest to be a good 'infinity distance' to set the fixed focus at for a lens this length?

I hope you understand my question - I would like to place the DOF as useful as possible with this lens.

[GPS]

Patrick, at F9 you have the hyper focal distance at 400m with the depth of field ca 200m - infinity. At F16 it's 225m with the DOF from 112.5m - infinity. If you take pictures with the lens focused at infinity you get anyway the the DOF from behind 200m to the infinity. With this kind of photography you usually go for infinity anyway. The infinity focus is better as it gives you at least that part in "perfect" focus and there are good reasons to believe that pics with good infinity focus fool the brain to see other parts in better focus too. You can goggle on it somewhere...
If you go for focus adjustment capability it will give you many practical problems not only with the focusing method but with the parallelism of both standards. Try to avoid that. I have build 2 cameras (600mm and 800mm) with fixed focus and I don't miss the focusing at all - it's all anyway in the DOF, what I need. If you miss the focusing make a second camera with it - you probably won't care about it...

[Doug Kerr]

Hi, Patrik,

In fact, the phenomenon of apparent compression of the distance between distant objects depends on the relative angular size of (a) the images of the objects as seen on the print and (b) the objects as they would be seen with the eye directly (from the camera position).

That in turn is influenced by:

1. Focal length

2. The magnfication of the print from the negative image

3. The distance from which we assume the print will be viewed.

(Having stated it that way, negative size is not involved.)

Thus, we cannot assess the degree to which that phenomenon will occur in some hypothetical "setup" by only considering the focal length, or by only considering the field of view (which is determined by focal length and negative size).

As a specific example: having taken a shot with a lens of any arbitrary focal length, and print the negative at a certain size (cropping as appropriate), and then view the print at a certain distance, if the angle subtended by the image of a object on the print is the same as the angle subtended by the object to the eye, then there will be no compression phenomenon.

If, when we do that, the angular size of the object on the print is greater than its angular size if viewed directly, the distances between objects will seem "compressed".

If, when we do that, the angular size of the object on the print is less than its angular size if viewed directly, the distances between objects will seem "extended".

This is because the ratio of the "apparent" distances between any two objects will be fixed regardless of focal length, magnfication of the print, or viewing distance. If the combination of those makes the angular size of the object on the print greater than its angular size if viewed directly, the user will take the distance to the near object (for example) to be less than it really is. (This is often why we use a long focal length lens and/or a high print magnfication: to make a distant object "look closer".) Thus the distance between the objects will also seem less than it really is.

Best regards,

Doug

[Doug Kerr]

Hi, Patrik,

[QUOTE . . .Knowing that I get 2/3 resp 1/3 DOF in either direction around this point, what would you suggest to be a good 'infinity distance' to set the fixed focus at for a lens this length?[/QUOTE]

I'm not sure I follow your teminology here, but if you mean that the total depth of field is distributed 1/3 on the near side of the distance at which the camera is focused and 2/3 on the far side (or even the opposite), that is not in general true

Best regards,

Doug

[Leonard Evens]

The Apo-ronar f9/600mm lens arrived today in very good condition from Germany.

Now it's a matter of having focus adjustments or staying with a fixed focus to start with.

GPS mentions fixed focus at infinity and not the hyperfocal distance.

Are there any suggestions for at which distance infinity kicks in, i.e. distance from the lens. Knowing that I get 2/3 resp 1/3 DOF in either direction around this point, what would you suggest to be a good 'infinity distance' to set the fixed focus at for a lens this length?

I hope you understand my question - I would like to place the DOF as useful as possible with this lens.

The 1/3 - 2/3 rule works only when you are focused at one specific distance, 1/3 the hyperfocal distance. It certainly doesn't work when you are focused beyond the hyperfocal distance when the back focus is infinite. In that case, the near focus point will be somewhat closer than half the distance at which you focus. Optically, it doesn't make sense to set a fixed focus lens at any distance but the hyperfocal distance, but the latter depends on the relative paerture. So you have to pick some standard aperture, which you will never go wider than, and use that to find the hyperfocal distance.

Say you never expect to use an aperture wider than f/11 with your 600 mm lens. Assuming you choose a coc of diameter 0.1 mm for 4 x 5, the hyperfocal distance would be about 327 meters, or about 1,074 feet. If you chose a coc of diameter 0.05 instead, you would have to double the hyperfocal distance. If you choose a different relative aperture, divide by the ratio of the f-number to 11. For example, using f/16, divide 327 by 16/11 ~ 1.4.

Another alternative would be just to focus as best you can exactly at infinity. Then, in principle, everything from infinity down to the hyperfocal distance (for the relative aperture) would be in focus. You might do that if you were more interested in keeping the far distance parts of the subject in good focus.

Since being able to find objects to focus on at specific distances is problematic, using such distances in setting the fixed focus is silly in any case. Instead, it makes sense to focus as best you can on infinity by choosing far distant objects, way beyond the hyperfocal distane, to focus on. In doing this, use a high power loupe and make several attempts, noting the position of the lens each time. Do this with several very distant points. You might even try the moon at night. Settle on an average of the different readings. You can choose that position for your fixed focus if you want to emphasize the far distance as noted above. Alternately, if you want to focus at the hyperfocal distance, you should move the lens further away from the gg by a small amount. That amount should be the product of the f-number with the diameter of the coc. Thus for a coc of diameter 0.1 mm and at f/11, you would move the lens an additional 0.1 x 11 = 1.1 mm further away from the infinity position. It is better to err on the short side than on the long side, so 1 mm would be adequate.

[EdWorkman]

"Feininger on Photography" 1953 edition p6 shows his 1944 outfit:
Two telescoping boxes with a bellows at the rear for focussing. Film size is not stated but 4x5 might be a good guess. The camera was supported on a single tripod with an additional bipod connecting the tripod feet to the forward end of the boxes- a pentapod on three feet I suppose.
The lens he used was the front element of a 21'' Ross- 40 inch focal length, with a Wratten A filter, I suppose that's yellow to counter enough of the abberations of a single lens element?
pp378-379 has 3 photos that explain and illustrate the effects of focal length
a telephoto view of lower Manhattan, a normal lens view fronm the same spot, and a [grainy] crop of the normal lens view to the same selection as the telephoto showing that the effect [except for sharpness] is identical.
My waiting project is to similarly mount a WW2 aero lens of 914mm- and now I wonder if a single element would work. That would certainly save several pounds

[Patrik Roseen]

Thank you all for valuable information and suggestions!

I am learning three different things here.
1) the importance of understanding the fundamentals of optics such as hyperfocal distance, the way to calculate DOF and the effect of circle of confusion etc
I intend to look further into the previous postings on this forum.

2) The reason for the 'compressed effect'. I have made the mistake of treating the film as the final product, when instead it is the print. So in a way the total optical effect is created by the taking lens in combination with the enlarger producing the final paperprint. ...and ofcourse also viewing distance. (Thanks Jeffrey, Doug, GPS, Jon, David and others)

3) Very good suggestions and experience of building cameras for looong lenses (Dan, GPS).

EdWorkman, Welcome to this forum thanks for the Feininger information!
I wish you good luck with your project.

GPS, I will follow your advice to start with a fixed infinity focus for the first version.

Leonard, Thanks for the suggestion to focus at the moon, that's really infinity alright!

[al olson]

Hi!

As an item of information, the Wratten A filter is red, aka #25.

al