Zeiss Luminar Zoom 2.5 - 5 Question

[adn25fr]

Hi,
somebody ask us on the french microscopy macro/nature observation and photography forum: "le naturaliste" about this lens.
I am curious and I bought one (not too expensive) after on EB.
I test it on bellows and I wright my opinion there (sorry in french):
http://daniel.nardin.pagesperso-orange. ... uminar.htm

I think that this lens has a too long focal lenght for use with small camera. It was for the big Ultraphot stand and the optical way was longer than 160mm. It is difficult to use with 35mm camera because the bellows is too long.

I would be happy to find an other zoom for macro work.
That would be easier to use a ring and not to change of lens or to change extension.

Last day, I read that page about one unitron zoom lens with RMS mount
http://www.unitronusa.com/zoom_obj.asp
I am interested if someone has tested this lens...

Best regards
DN

[Perl]

Hi !

Yes i Think its useless on Digital cameras

Best REgards
Pär

[enricosavazzi]

...
Last day, I read that page about one unitron zoom lens with RMS mount
http://www.unitronusa.com/zoom_obj.asp
I am interested if someone has tested this lens...

Best regards
DN

Sure,

http://savazzi.freehostia.com/photograp ... enses2.htm

And something general about this type of lens:

http://savazzi.freehostia.com/photograp ... enses4.htm

Edit: The above links are materials that I wrote a few years ago, and did not update afterwards. I improved my knowledge and refined my conclusions since. However, by and large these pages are still valid.

[Perl]

Hi !

Thanks for links - Will go for another one
shall see in links what one thats fit

Best Regards
Pär

[Perl]

Hi !

Wonder witch one of this Zoom Objective
preform best in your opinion ?

Best Regards
Pär

[enricosavazzi]

Hi !

Wonder witch one of this Zoom Objective
preform best in your opinion ?

Best Regards
Pär

I only tested the Unitron in comparison to other lenses. However, they all (including the Unitron) differ from more conventional photomacrographic lenses in having a longer working distance and a correspondingly higher effective f/ratio, so their resolution simply cannot approach the best alternatives. The diffraction limits imposed by the optical design simply cannot be beaten, and this is why I did not bother with more precise tests. We should not forget that these industrial zoom lenses are designed for high resolution videocams (perhaps up to 2-4 megapixel), not camera sensors with much higher resolutions.

I believe that in many cases these zoom lenses are simple modifications of the optics used in zoom stereomicroscopes with separate optical paths (Greenough type).

[Perl]

Hi !

OK i See - Many thanks for information
and experience

Are you in Uppsala Sweden ?

Best Regards
Pär

[enricosavazzi]

Hi !

OK i See - Many thanks for information
and experience

Are you in Uppsala Sweden ?

Best Regards
Pär

Yes, of course.