Large-format effect with a FF digital camera

[alex ph]

Have you looked through this article, with its embedded shots and the video? The idea itself of the construction seems smart and the result does pair with those old looking deep-DOF images. The IQ made me think of a combined effect of an f1.2 and tele lens, but fairly sharper.

What do you think, from technical and esthetic points of view, of this re-filming the matte screen?

[cooltouch]

Well, kudos to the kid for stickwithitness and originality. The images have a remarkable daguerreotype quality to them. I wonder how much of the effect he's achieving is due to the good ole Scheimpflug rule, though -- assuming, of course, he's using all the movements available with the large format portion of his rig. Naw, Scheimpflug is used mostly for perspective and DOF control. Looking at his stills he doesn't appear to be overly concerned with either. So then I wonder about that old Industar lens. Maybe it's providing "the look."

[luisalegria]

I have seen this sort of idea done before - basically shooting the groundglass (a specialized one) of an LF camera. The ones I have seen are done from behind the specialized groundglass, that is, in line with the projected image.

May want to try this actually. I have several 4x5 cameras and similar for such an experiment. The replacement screen is critical, and that bit requires experiments, as he said, a very matte finish, and if in-line, something like a fresnel that reduces light falloff off axis. Also extremely clean.

His rig is off-axis, with the digital camera underneath, and thats why he needs the PC adapter and that 15mm FF lens, which gives room on its image circle for movements. So he doesn't have to shoot through, just shoot at. Clever.

But not everyone has the $ for a 15mm FF lens for such a tinkerers project. So there must be another way.

If your goal is extreme shallow dof the longer the FL of your LF lens the better, and thus a bigger screen/larger camera, but I have a secret weapon, a 16.5cm Biotessar f/2.8, which is something that should give DOF effects of an f/4.5 300mm Tessar type which he seems to be using, but on 4x5 instead of 8x10.

Good idea and worth an experiment.

[ZoneV]

I do basically the same since 2016, but on a larger inter image format and still in prototype stage.
I work up to now with a epidiascope lens 480mm f/3.8 at ideally crop 0.1:

Portrait by Markus, auf Flickr

Bearded-Man by Markus, auf Flickr

After a bigger renovation in our flat, I can now start working on the real deal, to get my camera moveable (without a car).

[cooltouch]

Hey, if extremely shallow depth of field is the desired effect, then why not just use a very fast lens and be done with it.

For example, the Canon FD 85mm f/1.2 L or Aspherical. I have a copy of the Aspherical. Here's a shot I made with my 85 Aspherical set wide open. I was using my Canon F-1 and shooting Kodak Elite Chrome 100 slide film. The point of focus was the lettering on the camera's lens.



Same camera and lens. Lens wide open. Fuji Superia 400 film.


This was shot with my 10.1mp Canon DSLR. I used an adapter with no glass, hence macro only. Same as above, 85 wide open.


The point of focus in the above image:


The edge of our storage barn. A study in depth of field/bokeh. Same lens, wide open, NEX 7 at ISO 100.

[ZoneV]

On my ultra large format camera I have something like 48mm f/0.38 relative to 24x36mm imaging - at the moment.
So this puts my Mitakon 50mm f:0.95 to shame in terms of DOF.

[ZoneV]

[luisalegria]

Its not a weird lens, its just very shallow dof due to a long focal length.
The kicker though is that this shallow dof is achieved on a "normal" field of view, an 8x10 projected image, for which 300mm is "normal".

Thats part of the magic of large format. An f/4.5 Tessar like he's got (that what it probably is), on large format, has narrower dof for a similarly framed subject than a 50mm f/1 on 35mm/FF.

[luisalegria]

Good luck Marcus.
You have great samples.

Show us your version when you can.

[kds315*]

Quite interesting, wonder if I should build something the like myself, always a nice challenge for an engineer

[visualopsins]

Use process lens inside nested boxes. Project a nice big like 24x36" ground glass...

[cooltouch]

I have a 300mm f/5.6 Tessar that I bought at an astronomy swap meet years ago. Never done anything with it. The seller told me it was from a paint comparitor. Okay. More recently I've found plans and examples of "copyscopes" made from this optic. Apparently it makes a good wide-field telescope.

I snagged this image of the Tessar off the 'net:


If you google "copyscope" you'll get lots of hits. After you do, be sure to click on the option that searchs for "copyscope" only and not "copyscape" also.

Here's one site that I've known about for years. When I finally get around to building mine, I'm going to use it as a resource:

http://www.dma1.org/~wagner/copyscop.htm

Here's a really nice copyscope somebody built using the same Tessar I have:

https://www.cloudynights.com/articles/cat/articles/carl-zeiss-300mm-f56-s-tessar-rft-r3044

[iangreenhalgh1]

[alex ph]

Thank you, fellows, for your input. The whole discussion with your precisions gives a better sense to the article and gives some inventor's adrenaline.

Several years ago I was tempted to put a Sony Nex on the back of a MF camera to get a "vintage" look of the shots. Some of you wrote that you already did a thing of the kind. I did not advance much in the project later, after having tried some tests shots. They showed to me that the old lens did not shoot "vintage", it gave an "ordinary", good quality look to the image, if you make an imaginary correction of the undesired stray light effects produced by such "freelensing".

The idea to abandon one-sensor system and to use the matte screen as the second sensor to enlarge the DOF seems to give quite a different option. You explain well that a special glass is needed and probably a shift adapter is required even with the digital camera installed on the center axis.

I do not have an old MF camera now by the hand. But much later, in a sunny shiny day, I wish to try it, just to have an idea, with its ordinary matte glass and Nex equipped with a rather wide and close focusing lens. Something like Sigma Mini-Wide 28? Too curious about what may come out from the center of the matte glass.

Markus, Michael, thank you for your samples. Very interesting. Please, fellows, share more of your examples that give a better idea of the performance of your experimental equipment.

[tb_a]

Sometimes I also like this vintage look produced by these old LF cameras more than 100 years ago.
However, it's possible with much lesser effort to reach a similar goal with present day equipment and without LF camera:



A FF DSLR with a 85mm/F1.4 lens and a little bit of post processing. That's all.

What do you think about?

[luisalegria]

That's a good shot, and it is of course a fine lens.

[luisalegria]

What the fellow did is a supersized version of these things -

http://www.letus35.com/dof-adapter/

https://beastgrip.com/products/beastgrip-dof-adapter

The same idea - they mount 35mm lenses to project their images on a groundglass, which are then recorded by a camera with a small sensor (iphone, etc.) or dedicated videocameras.

Because these things have small sensors and so very short FL lenses, they can't do shallow DOF.
So this is a workaround.

The complications -
- Dirt, imperfections in the groundglass, which is difficult to make perfectly smooth and with no grain - this sort of thing will show up very well indeed as the camera lens will be focused on the glass itself. So the sophisticated versions (the letus ones for instance) have a vibrating or rotating groundglass, to make the image smoother.
- Close focus but with enough of a wide angle to take in the whole groundglass. Most of these things incorporate a close focus filter.
- Reversed image. Some of these have prism to rectify the image.

[tb_a]

[jamaeolus]

Somehow I missed the article the OP is referring to.

Lovely shots.

[kds315*]

[kds315*]

[alex ph]

Stumbled upon another attempt of this kind, this time technically based on re-using of digital scanner. Even though the resulting image is closer to Lomography, mentioned in one of the neighbour posts, rather than to a "real" LF emulsion.

[jamaeolus]

I hope to try something similar. Using a computerized motion controller as a way to get stitchable tiles using my a7rii in lieu of an (expensive) digital back. I'll have to fab some device analogous to a dark slide.

[alex ph]

That sounds really intriguing. I am aware that this is the kind of projects that does not realize from one day to another. Please share your results as long as you arrive to get some!

[visualopsins]

Yes! Not from nodal point photos stitched together. From rig that moves camera x-y inside say 4x8' grid. A LF sensor, if you will...