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kilimanjaro1996
25-Oct-2009, 19:57
Hello,

I bought a Kodak Aero Ektar 7" f/2.5 in San Jose photo fair on Saturday, and tested out with some color Polaroids. Apart from the yellowish tint people talk about, there is a general softness/fuzziness over the whole photo. It's as if someone smeared some serious vaseline on the lens, even though the front and back surfaces are clear and clean.

I dissembled the elements, and found that the cemented pair in the front group has something wrong. I'm talking about the cemented element 2 and 3 in this Biotar design, if element 1 is towards the object and element 7 is towards the film. There are some fuzziness between the two elements, so is it balsam fault?

Are there anyway to fix it other than hunting for another front group or new Aero Ektar? On the other hand, this particular fault does create a specific visual quality.

Thanks,
Zheng

kilimanjaro1996
25-Oct-2009, 20:12
Just a quick scan of the Fuji FP100C instant film:

John Cahill
25-Oct-2009, 20:51
Just a quick scan of the Fuji FP100C instant film:
******
One approach which sometimes works was advised to me by an old-line repairman. That is to place the lens in a cold oven. Then, very gradually, over a couple of hours, to gently raise the temperature to about 325 degrees. Leave it that way for an hour or so, then gradually relower the temp the same way. He told me this will SOMETIMES re-cement the Canada Balsam cementing the elements together.
I was advised to do this with an Enlarging Anastigmat. Although it did not solve the problem; neither did it do anything untoward that I can see.

Daniel_Buck
25-Oct-2009, 23:29
It could be (if it's been serviced) that the elements were not put back in the right order? My Aero Ektar produces a very soft look, probably at least twice as much as yours, and I get very strange highlights! It was serviced before I got it, and I suspect that the elements were not put back in the correct order. It gives me results like this, I focused on the pine needles on the christmas tree (they are in focus at the middle of the image) but the highlights from the lights go crazy!

When shooting a scene with no super bright highlights (like the photograph you posted) it just has a very blury soft layer over the sharp image, like a soft-focus effect.

http://404photography.net/wip/4x5/radioactive_christmas_01.jpg

Bosaiya
26-Oct-2009, 04:40
It could be (if it's been serviced) that the elements were not put back in the right order? My Aero Ektar produces a very soft look, probably at least twice as much as yours, and I get very strange highlights! It was serviced before I got it, and I suspect that the elements were not put back in the correct order. It gives me results like this, I focused on the pine needles on the christmas tree (they are in focus at the middle of the image) but the highlights from the lights go crazy!



WOW!

kilimanjaro1996
27-Oct-2009, 20:23
Daniel: thanks for the suggestion. I will double-check the assembly of elements.

John: I will use this method as the last resort. :-)