problem with a rollei T lens

[rolleistef]

Hello all,

After 6 years or so working together with my lovely Rollei T, I noticed the lens decementing, that existed as traces before, started getting really serious.
However, I was not sure wether the problem I had on photographs was due to it or to bad developping?

please let me know : you can see on the right hand side and top left corner some dark marks (actually lacking density on the negative) and i'm not too sure to what I might be caused by :



thanks in advance...

[Dan Daniel]

Just to be clear, it is the back group that is decementing? The front group- in front of the shutter blades- is an air-spaced pair.

I had an older Tessar on an MX that had some strange brown glop work its way onto the edge of the second lens element. I was able to open the front group and remove it for cleaning.

But this doesn't answer your dark areas in the shot above. I don't have any answers. The right side, with a somewhat straight line, doesn't strike me as a lens issue, more development or light leak or something. The upper left looks like vignetting but I don't know if a de-cementing lens group would cause this.

[rolleistef]

That was a good question. It's the back pair (which isn't air spaced) and there are indeed some brownish things on the lens. Maybe oil? thanks for your remarks in any case!

[f16sunshine]

You might have to try a "Brick wall shoot to see if the lens is actually effecting Image quality. Even then you may not know for sure as a Tessar is not terribly corner sharp until stopped down... which, stopping down should clean any IQ issues related to edge separation. The sample image above looks like it could be caused by a dev elopement issue or even a lens hood that twisted past proper alignment ( a problem I have often with one of my old beaten hoods on the rollei T).

[rolleistef]

right it's a development issue then...
I guess the camera will have to retire soon or later ... an Autocord seems more and more tempting!
thanks for your help anyway!!

[leicapixie]

The area is too regular for a lens problem. Possibly your roll is not sufficiently tight on "take-up" spool. Worrying about the poor quality of the Tessar? Duh! Irving Penn might have been somebody with a better lens..
Most lenses are more than sufficient for photographers.. The Tessar is one of the best. The basis of most "macro" and some"micro" Nikon lenses..Sure some of the new Leica lenses are way sharper.."Uber-sharp". You are using 6 x 6 which is 4x bigger than 35mm. You don't need all that resolution.
The backgrounds of the aspheric lenses look like shards of broken glass.
The steel spring that rest against film may be slightly weaker.. be very careful adjusting. See if with a dummy roll, the paper is tight on spool?
Could be a process hitch.

[graywolf]

I would say a developing problem. Not a light leak. Lens problems do not show as straight areas like on the right. Could be something in the light path of the taking lens, but you should be able to see that just by looking in the back of the camera. So, processing problem by elimination.