Lubitel 75mm T-22 lens image circle for 4x5"?

Fulvio · May 19, 2008

Does anyone know precisely what's the image circle of a Lubitel T-22 75mm triplet lens? I know it's a medium format lens, but I was just wondering if I can get round images on 4x5" film from it or the circle is cropped on 4x5" and I need a larger format to have a perfect circle.

thanks

walter23 · May 19, 2008

I very much doubt it would cover a full 4x5" sheet given the (presumably-tessar style) design and focal length, but you'd at least get a 6cm diameter circle on sheet film. Can't hurt to try, you can probably reversibly remove the lens (just make sure you mark the focussing gears so you can get them reattached in the right register, or you'll lose proper focus through the TLR viewfinder lens).

Fulvio · May 19, 2008

yes, the point is not to have a 4x5 coverage, I want a circular image on film. I don't have a Lubitel yet, so I was asking first. Thank you

Fulvio · May 20, 2008

a friend of mine lended me one... it appears the coverage is roughly 11x11 cm... I'd say something between 10x10 and 11x11 centimeters at infinity/full open; it will not cover 4x5" neither deliver a circular image as I was hoping. I guess one needs at least a 5x7" to obtain that effect...

I did some research on the internet... it appears that this image circle size (~100-110mm) is very frequent among medium format tessar lenses in the 75-110mm focal length range...

infest · May 20, 2008

Fulvio said:
Does anyone know precisely what's the image circle of a Lubitel T-22 75mm triplet lens? I know it's a medium format lens, but I was just wondering if I can get round images on 4x5" film from it or the circle is cropped on 4x5" and I need a larger format to have a perfect circle.

thanks

It doesn't cover 4x5, (be happy) but you won't get a "perfect" circle - just a circle with smudge borders.

Tomf2468 · May 20, 2008

Put a long round lens shade on it. It will take some experiments to find just the right length, but it will give you a "mechanical" limit to the lens's coverage and form a nice circle.

Fulvio · May 20, 2008

Tomf2468 said:
Put a long round lens shade on it. It will take some experiments to find just the right length, but it will give you a "mechanical" limit to the lens's coverage and form a nice circle.

good idea.. actually I could do that with any lens, but I wanted the toy camera feeling of a cheap lens

thank you

rwyoung · May 20, 2008

Lens shade + Vaseline (petrolium jelly) smeared on the lens (or a filter if you don't want to clean the lens) perhaps

jimgalli · May 20, 2008

I have one more of the wee petzval's to sell. Here is what you can expect. The page comes up with half frame 4X5 images but if you click on the images it shows full frame 4X5 coverage. It's about 85mm and a true petzval. No aperture. Contact me off line if any interest. jimgalli at lnett dot com

walter23 · May 20, 2008

Fulvio said:
good idea.. actually I could do that with any lens, but I wanted the toy camera feeling of a cheap lens

thank you

You may be disappointed with the nice sharpness of the lubitel lens, if you want the toy camera look. Maybe it's not a Zeiss hasselblad T* lens or anything, but it's far from a crappy lens.

I guess the areas outside of the 6x6 film area might be degraded though.

Tomf2468 · May 20, 2008

My Lubitel was nice and sharp. It scratched film, each and every roll, but it was sharp!

Murray@uptowngallery · May 20, 2008

Minor point...if it's a triplet, it's not a Tessar...although the Tessar is considered a variant of a triplet, with one element split into two components.

Sam Wang has used a 'wide angle' 50 mm lens from I think some kind of Mamiya MF camera and got a nice clean round image on 4x5. I didn't find out exactly what lens...nor was it inexpensive or available to me.

makan · May 21, 2008

walter23 said:
You may be disappointed with the nice sharpness of the lubitel lens, if you want the toy camera look. Maybe it's not a Zeiss hasselblad T* lens or anything, but it's far from a crappy lens.

I guess the areas outside of the 6x6 film area might be degraded though.

That's exact. Having the camera saved from hands of a not knowledgeable amateur I always wondered at it quality/simplicity ratio.

makan · May 21, 2008

Tomf2468 said:
My Lubitel was nice and sharp. It scratched film, each and every roll, but it was sharp!

Why did you let the camera scratch all your films? The offending part is usually not difficult to find and a little friendly talk can make wonders

makan · May 21, 2008

Tomf2468 said:
Put a long round lens shade on it. It will take some experiments to find just the right length, but it will give you a "mechanical" limit to the lens's coverage and form a nice circle.

Not true, sorry. If you make it long enough to make "a nice circle" (sharp edges?) it will be too long and will give just a small image circle (otherwise its dimension would be colossal). If you make it short, it won't give you "a nice circle" then. Try to put a finger in front of you lens - when you finally can see it sharp (provided the lens is focused at infinity) it will be too far from you. Closer it won't be sharp. The same is valid for a rounded lens shade.

Fulvio · May 21, 2008

it's fine, my purpose is not having a sharp round edge, I want the image to fade away gradually

makan · May 21, 2008

Fulvio said:
it's fine, my purpose is not having a sharp round edge, I want the image to fade away gradually

good, then use it as is.

Lubitel 75mm T-22 lens image circle for 4x5"?

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