Home

Please support mflenses.com if you need any graphic related work order it from us, click on above banner to order!

SearchSearch MemberlistMemberlist RegisterRegister ProfileProfile Log in to check your private messagesLog in to check your private messages Log inLog in

CZJ Pancolar 1.8/50 with a deep scratch on the front lens
View previous topic :: View next topic  


PostPosted: Sun Dec 27, 2020 2:20 pm    Post subject: CZJ Pancolar 1.8/50 with a deep scratch on the front lens Reply with quote

As it is relatively well known, front lens defaults may have a very subtle impact on lens' performance. I remember an impressive report years ago by someone showing tes shots taken with a lens with literally broken front glass: it still worked pretty fine, the main difference was in flare resistance, some contrast fall and bokeh shape.

Personnaly I already had an experience with Jupiter-8 full of fungus and still a very good performer. Here is another confirmation of the "glass resilience", a Carl Zeiss Jena Pancolar 1.8/50 with a deep circular scratch on the front glass which looks pretty scaring.



I did not have an opportunity to check it against the shining sun, as there is no sun in these days. Otherwise I could not see any perceptible flaws in its perfomance. In the dull light of these days the scratched lens renders as well as another, perfectly preserved copy of Pancolar.

#1


#2


#3


PostPosted: Sun Dec 27, 2020 3:46 pm    Post subject: Reply with quote

That subtle impact ,would show starting from f8 ....


PostPosted: Sun Dec 27, 2020 3:59 pm    Post subject: Reply with quote

Which model Pancolar ? I think I have a mint one with parts missing from the aperture mechanism.


PostPosted: Sun Dec 27, 2020 4:34 pm    Post subject: Reply with quote

Good point, Kiddo. I tested it up to f5.6 but did not think to close the iris more.

Lloydy, this is a "zebra" version from 1969 or 1970.


PostPosted: Sun Dec 27, 2020 5:09 pm    Post subject: Reply with quote

At some angles with strong light source(s) just out frame you'll see flare. My experience with small nick front element of 1.8/85.


PostPosted: Sun Dec 27, 2020 5:33 pm    Post subject: Re: CZJ Pancolar 1.8/50 with a deep scratch on the front len Reply with quote

alex ph wrote:

... a lens with literally broken front glass: it still worked pretty fine, the main difference was in flare resistance, some contrast fall and bokeh shape.





If you paint the scratch or the chipped part of the lens with black paint, the flare will go away. This is an old trick that I believe is not very much known these days.


PostPosted: Sun Dec 27, 2020 5:36 pm    Post subject: Reply with quote

Definitely, both flare and black paint are very interesting points. I should catch up a sunny day and test all that.


PostPosted: Sun Dec 27, 2020 7:17 pm    Post subject: Reply with quote

out of focus highlights "bokeh balls" is the other place to look at effects.


PostPosted: Sun Dec 27, 2020 7:32 pm    Post subject: Reply with quote

The bokeh would be interesting to test, as the scratch is rather thin and long.

Here and here are a couple of interesting articles (accompanied with test shots) exploring the cracked front glass issue.

UPD: Ha-ha, and there is a similar funny story about de-bugging an expensive lens.


PostPosted: Sun Dec 27, 2020 8:10 pm    Post subject: Reply with quote

My experience with black paint was not so good. Can be zones in shadows in the film (Old times).

A years the pancolar 50 is not expensive, perhaps you can buy another in good shape


PostPosted: Sun Dec 27, 2020 8:41 pm    Post subject: Reply with quote

Thank you for your piece of experience, papasito. I already have two or three Pancolars in their different iterations. This copy was just offered at a very reduced price due to the scratch, and my curiosity was stronger than the strict reason.


PostPosted: Mon Dec 28, 2020 9:12 am    Post subject: Reply with quote

What size sensor did you use, Alex?


PostPosted: Mon Dec 28, 2020 10:38 am    Post subject: Reply with quote

That was a Sony APS-C.


PostPosted: Mon Dec 28, 2020 12:05 pm    Post subject: Reply with quote

alex ph wrote:
That was a Sony APS-C.


I just wondered if the light from the damaged area of glass would be outside the sensor.


PostPosted: Mon Dec 28, 2020 12:12 pm    Post subject: Reply with quote

You might be right! So, the programme for a sunny day in spring is getting more and more precise: Sony FF + stray light + patched background (for OOF shapes) + f8 and narrower + black marker.


PostPosted: Mon Dec 28, 2020 4:05 pm    Post subject: Reply with quote

Aps-c uses part of the image circle, but all of the front element surface unless aperture diaphragm is closed.