Reversed-Element Tessar as a Soft Focus Lens (?)

[leighmarrin]

Several years ago I picked up a Graflex non-auto Series D 3x4 reflex that has an uncoated B&L 6 3/8" f4.5 barrel lens on it. The front cell was a little hazy, so I took it apart and cleaned it. Several years later I finally got around to using it, and was surprised how fuzzy and flarey the results were.

I finally figured out that I'd reversed the rear element of the front cell. With it correctly positioned, it's nicely sharp.

So here's a quickly done example of the effects of the correctly positioned versus reversed element on a 4x5 press camera, at f11, focused at about two feet:
[IMG][/IMG]

[Larry H-L]

I reversed the front element of a 50mm Russian-clone Tessar and now use it as a soft-focus lens on a dSLR. Results are more pronounced than what you show, but perhaps that is because the 50mm is a faster lens?

[Jim Galli]

Tried this yesterday with a worthless Velostigmat 6 3/8" Enlarging tessar. Easily accomplished but difficult in the extreme to judge a focus and seems a bit too smeared to be useful to me. I ended up re-assembling the lens with the right orientation and leaving an extra 1/8th inch gap between the 2 front cells ala Velostigmat fuzz-u-lator. That seems to me to be a richer trade off.

BTW, I could not have produced the images above with the Velo, so maybe there's something to Brand differences, ie. B&L instead of Wolly Velo. I have a nice 5X7 B&L at home that I'll tamper with for another try.

[Eric Rose]

I think there is a difference between the soft focus look and just plain out of focus.

[leighmarrin]

More element-flipping with the same B&L 6 3/8" series Ic barrel lens, this time at f8 focused at about five feet.

I probably should have used an easily-recognizable test object, but I sorta like the mysterious fuzz... FWIW, this flarey-thing is an unusual electric-floral-sculpture hanging inside a storefront display window. The ends of the flower are small lights alternating with small shiny spheres.

Photos were taken at dusk, with only a little natural sunlight. The right-hand photo has the reversed element, and like the lantern shots, also has a small relatively sharp center.

[IMG][/IMG]

[leighmarrin]

And here's the reversed element with the lens wide open at f4.5 --Contrast was lower, so after scanning I increased it, and also decreased brightness a bit.

[IMG][/IMG]

Highlights away from the center appear to now have two or three "prongs". (Umm.. perhaps I could have got a similar effect with one of the many special-effects filters from the old Spiratone catalog or a vaselined UV filter, but this is "funner".)

[Paul Fitzgerald]

Thanks for posting this, I just received a B&L Aero-Tessar 600 f/6 and will try this out after I get it mounted.

[leighmarrin]

Paul, I'd be interested in your results, including the non-modifed ones. What sort of camera and lensboard is required for a 600mm Aero-Tessar?

[Paul Fitzgerald]

Hi there, the Aero-Tessar is one large lens, it needs at least an 8x8 board and at 24" it needs an Ansco 5A double extension studio camera OR some Air Force monster. It's 5 1/2" across the barrel and each cell weighs 5+ lbs, it's in a phenolic resin fiberglass barrel (really tight threads) and there is no provision for a mounting flange or iris assembly. Mounting it and installing an aperture was interesting.

The image is tessar sharp with less contrast being uncoated, nice choice if you can use it. Modified it's only slightly less drastic than the f/4.5 and adjustable by f/stop.

This conversion can be done to a B&L 8x10 Tessar 1C but not to the 11X14 or 14X17, the cells are crimped.

I was wondering how Hurrell did the photo below, this might not be the exact answer but it's really close.