Front Element Separation

[jamusu]

I have a couple of pro-tessar lenses with front element separation that I have yet to use. Are these lenses usable. Will they have a negative impact on the quality of my pictures.

Jamusu.

 

[jamusu]

Anyone???

Jamusu.

 

[3Dfan]

Your question is not exactly clear to me. Perhaps if you rephrase the question and define exactly what you mean by "front element separation" an answer would be offered. Do you mean it uses front cell focusing? Or are you saying the front element is damaged?

 

[jamusu]

The front element/lense has a rainbow look to it. It has been said that the cement that was made to glue the lense causes this to happen in some lenses.

Jamusu.

 

[elekm]

In general, front-element separation won't have an impact on sharpness, but it could make the lens more prone to flare and lowered contrast.

Separation seems to be common with the Pro-Tessars for the Contaflex (these are the Contaflex accessory lenses, right?).

I think you'll find that if you're careful and avoid those flare situations, your photos will be fine.

 

[jamusu]

Yes it is for the contaflex. Should I purchase some lens hoods?

Jamusu.

 

[Dan Fromm]

Before you spend more money, try the attachments out.

I suggest this because I have a Kodak 25-15 adapter for the 25/1.4 Cine Ektar II that has the same rainbow effect. The effect is called Newton's rings and is due to interference between two surfaces. The adapter's Newton's rings are visible on my Beaulieu's ground glass and film shot with the lens plus adapter has captured them.

If you can see your Pro-Tessars' Newton's rings through your Contaflex's viewfinder, the Pro-Tessars are unusable.

Mike, there are separations and then there are separations.

 

[Mark Layne]

Zeiss did not use Canada Balsam on these lenses but some epoxy type adhesive which is almost impossible to repair when separated. If the separation is on the outside edge chances are they will work just fine
Mark

 

[epatsellis]

In the past, I know Rick Oleson had suggested that a small drop of light oil, wicked in from the edge of the element, (at only one edge of teh seperation, to allow air to escape) and given a little bit of time to seep in via cappilary action will work, I never believed it, until I tried it on a lens I had and was going to throw away or try to get $20 on ebay. done carefully, it works and reduces the visibility, and flaring effects, perfectly.

erie

 

[lens_hacker]

I've used "Index Matching Fluid", like what you use for an oil immersion microscope lens, to repair separated elements. In my case, the elements had "completely separated" and were almost opaque. Took the cemented pair out, cleaned them with 99% Isopropyl Alchohol, and used a drop of the IMF. Without the oil, the elements showed Newton's Rings. Five years later, the Canon 135/3.5 RF lens is still crystal clear.