Damaged element but still works!

[JHannon]

Hello All,

I recently took a chance and bought an "AS IS" Zeiss Distagon 50mm f 4 lens for the Rolleiflex SL66 at KEH. The lens was described as having a damaged element and the price was around $100 so I bought it. Rollei SL66 lenses are hard to come by, especially the wide angles.

I received it yesterday and the second element (the lens has 7 elements) from the front has a 1/4" bubble at the edge. Not even covering the aperture. I don't know how it got there the lens case looks perfect.

Anyway, I ran a roll of film through it of the rear of my house ranging from full f4 to f22. On the light table with the 10X loupe, I see a slight blurr bottom right edge at F4 and it seems to go away at f5.6 and through f22.

Any other tests I can do and do I have a good user lens here?

I am just happy to finally have another lens other than the 80mm...

Thanks for your advice,
John

 

[David A. Goldfarb]

Yeah, there are some great deals like that to be had. Mine was a Canon FD 400/4.5 SSC that was mechanically perfect with case and four drop-in filters, but it had a serious fungus infestation. $125 for the lens plus $80 for a cleaning, and it's got some etching on the glass, but it's still takes darn good pictures.

 

[Jeremy]

Always been a fan of KEH.

 

[Gerald Koch]

Anyway, I ran a roll of film through it of the rear of my house ranging from full f4 to f22. On the light table with the 10X loupe, I see a slight blurr bottom right edge at F4 and it seems to go away at f5.6 and through f22.

One of the laws of optics states the all portions of a lens image all portions of an image. Therefore, if you were to see any effect of the bubble it would be that of an overall degradation of the image and not in specific portion.

Years ago when it was difficult to produce large amounts of optical glass it was perfectly permissible to sell lenses with a bubble or two.

 

[JHannon]

One of the laws of optics states the all portions of a lens image all portions of an image. Therefore, if you were to see any effect of the bubble it would be that of an overall degradation of the image and not in specific portion.

Years ago when it was difficult to produce large amounts of optical glass it was perfectly permissible to sell lenses with a bubble or two.

Thanks for your response. This seems more like impact damage than a bubble in the glass. The lens case shows no sign of dents, etc. Stopped down, I see no distortion but at full aperture I see a blurr lower right corner.

I just did not know how a wide lens reacts to this type of problem. I guess I will just use it and see how it goes.

Thanks,
John

 

[Mongo]

Any other tests I can do and do I have a good user lens here?

I think you've done all of the testing that you need to do John. Shoot with the lens at f/5.6 or smaller and you'll probably be fine. You might want, when the opportunity presents itself, to try some shots with a bright light source to see if you get more flare or not. It's hard to predict these things (especially without actually handling the lens), but my guess is you got the best deal you're ever going to get on a Rollei lens. Congratulations!

(By the way, I have a process lens that I use for LF...it's got edge separation the whole way around the front element that impinges onto the image when the lens is wide open (f/8). Stopping down to f/11, I've never seen any effect at all from the separation, even with the sun near the corner of the image. I'd think a front lens problem would be likelier to cause a problem than a 2nd lens imperfection.)

Be well.
Dave