Aero Ektar please help

[photojournalism]

Hello!
Is the front element of Aero Ektar (cemented doublet and spaced lens) producing any image?
Thanks.

[Jim Noel]

Take off the rear element and try to focus the front and then you will have your answer.

[photojournalism]

Thanks, it works!!!
If serious, I have no Aero Ektar, just going to buy it. So need to know how the front element works. As I understand this is a tele lens, so the rear group should be a negative and front group should be a solo lens. But may be I'm wrong.

[Dan Fromm]

Not a tele lens. A more or less symmetrical double Gauss type. Why do you think it is a tele?

Oh, and by the way, the 7"/2.5 Aero Ektar's flange focal distance is a bit shorter than focal length. This is normal for double Gauss types, which are often a bit telephoto. But tele lenses in the conventional sense they are not.

[photojournalism]

Thanks! I found Aero Ektar description and scheme. It's really close to double gauss.

[dystopia]

can anyone who has a ektar 2.5 let me know if the lens is meant to have a rear element? as mine doesnt seem to have one.. (i havent tested it yet still waiting on a jolo board to come). thanks

[Corran]

Uh yes the AE should have a rear element!!

[EdSawyer]

definitely has a rear cell behind the aperture, yes.

[Wayne Aho]

The rear element on the 7"/2.5 will show a little bit of yellow/brown coloring. The rear glass contains radioactive thorium, and will be about 2-3 millirem on contact. Store it away from the kids.

[dystopia]

thanks for all your responses! - so you guys actually have this lens? thank you all again for letting me know.

i purchased the lens from ebay and they never said anything about this on the listing..so that pisses me off! it for my graflex i even have a jolo mount in the post. though it was bit odd as i have never seen a lens without a rear element expositing the aperture blades. hmm! dammit.

that scares me it doesnt have the rear element on also.. exposing more radiation!? gahhh - scared (dont have anything to test it either - thats stay far away as possible from me).

[Corran]

Return it!! Sounds like you're missing the element with radiation anyway.

[dystopia]

Return it!! Sounds like you're missing the element with radiation anyway.

thanks! yeah definitely returning it! btw can you remove the rear element from one lens to another or is it impossible to do that? (as i might be able to get a worse condition lens) and switch the back element.

[Corran]

I've had many AE's here, and only one was I ever able to take off the front and rear elements. They get bound up because of the aluminum or something and just won't unscrew without a lot of work.

[Dan Fromm]

though it was bit odd as i have never seen a lens without a rear element expositing the aperture blades.

There are such lenses. 200/4 Micro Nikkor AI/AIS, for one. I have one.

But as others have already told you, 7"/2.5 Aero Ektars have rear cells. I'm sorry you were stung, go after the seller.

[dystopia]

I've had many AE's here, and only one was I ever able to take off the front and rear elements. They get bound up because of the aluminum or something and just won't unscrew without a lot of work.


There are such lenses. 200/4 Micro Nikkor AI/AIS, for one. I have one.

But as others have already told you, 7"/2.5 Aero Ektars have rear cells. I'm sorry you were stung, go after the seller.

thanks for the information guys very helpful, helped a ton! will be on here more. cheers