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Using odd lenses on Micro 4/3rds cameras
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PostPosted: Tue Nov 24, 2009 10:15 am    Post subject: Reply with quote

Well, I have just finished some tests I made with Tevidons I have here and I can confirm the findings as mentioned by Sebastien (abazz). From about 25mm focal length onwards vignetting disappears, so the full set consisting of the focal lengths 10, 16, 25, 35, 50, 70, 100mm leaves out the 10+16mm versions, due to quite some vignetting (except someone likes that effect). The 25mm is borderline, so still some vignetting is visible but just in the corners (a nice useful effect at times); this disappears if the 16:9 format is being used. From 35mm onwards all vignetting has disappeared.

Tevidons are tack sharp and contrasty lenses once made in the former GDR by Carl Zeiss Jena (later sold to DOCTER OPTICS which continued making them; and still does btw.) as video lenses to protect their border safety, massively built (the first series) and in the later second series was built much lighter. They came in c-mount (rare) and a special bajonet mount to fit their vidicons. The spectral range is 400-1000nm fully achromatically (some say apochromatically) corrected (!!), so there is no focus shift, if these lenses are being used for IR photography in the 750-1000nm spectral band.

I have now found a way to convert these bajonet mount lenses to c-mount using a newly designed precision mount to make these usable for mft (micro 4/3) cameras. More about that later.


Last edited by kds315* on Tue Nov 24, 2009 12:53 pm; edited 1 time in total


PostPosted: Tue Nov 24, 2009 12:01 pm    Post subject: Reply with quote

Klaus,

Have you tried your 18-90/2 Vario Tevidon on the GH1 as well?


PostPosted: Tue Nov 24, 2009 12:55 pm    Post subject: Reply with quote

dickb wrote:
Klaus,

Have you tried your 18-90/2 Vario Tevidon on the GH1 as well?


Not yet Dick since the mount is very different, but it appears that there will apparently be some vignetting.


PostPosted: Tue Nov 24, 2009 1:30 pm    Post subject: Reply with quote

apicius9 wrote:
Excellent summary Sebastien! I was fortunate enough to get my hands on a larger lot of c-mount lenses

You're welcome, Stefan. That glorious heap of lenses in your avatar is mouth watering...

apicius9 wrote:
Sorry, I have been spending more time shopping for lenses than taking pictures recently and my job is crazy right now, but I'll try to find a few pics to upload...

Please do !

Cheers!

Abbazz


PostPosted: Tue Nov 24, 2009 1:36 pm    Post subject: Reply with quote

kds315* wrote:
Not yet Dick since the mount is very different, but it appears that there will apparently be some vignetting.

That's what I was afraid of, Klaus. I find the C-mount zooms quite disappointing regarding coverage. But the longer Tevidon primes look very interesting, if you see what I mean ...

Cheers!

Abbazz


PostPosted: Tue Nov 24, 2009 3:14 pm    Post subject: Reply with quote

Just some TEVIDON test pics taken at ugly + nasty weather fully open shot at infinity.
Full sensor format using Lumix GH1, just resized, no cropping or sharpening or contrast
enhancement applied - straight from the cam.

f=35mm


f=50mm


f=70mm


PostPosted: Wed Nov 25, 2009 12:04 am    Post subject: Reply with quote

kds315* wrote:
Just some TEVIDON test pics taken at ugly + nasty weather fully open shot at infinity.

These pictures look very promising. The corners are not very sharp on the 35mm shot, but this has to be expected at F/1.9. Vighetting, chromatic aberrations and distortion seem to be absent. Thanks for the pictures, Klaus.

Cheers!

Abbazz


PostPosted: Wed Nov 25, 2009 3:15 am    Post subject: Reply with quote

kds315* wrote:
The 25mm is borderline, so still some vignetting is visible but just in the corners (a nice useful effect at times); this disappears if the 16:9 format is being used. From 35mm onwards all vignetting has disappeared.

When you shoot in 16:9, 3:2 or 1:1 with the E-P1 (or E-P2, Panasonic G1 or GF1 for that matter), the camera is cropping the picture, that's why you can easily hide the dark corners under the rug by choosing the 16:9 aspect ratio. It is more difficult with the GH1, because it's the only M4/3rds camera that has a constant field of view in 16:9, 3:2 and 4:3. On this particular model, the oversized sensor allows for multiple aspect ratios while retaining the angle of view (meaning the image circle remains the same). Here's a page on Panasonic's website with a nice Flash animation presenting the trick:
http://panasonic.net/avc/lumix/systemcamera/gms/gh1/high_image.html

And here's a illustration from DPReview:



Cheers!

Abbazz


PostPosted: Sat Nov 28, 2009 8:15 pm    Post subject: Reply with quote

Thanks Sebastien,

I should read manuals more I guess.... Wink Wink


PostPosted: Sun Nov 29, 2009 2:45 am    Post subject: Reply with quote

The Tevidon images seem excellent considering all the circumstances.


PostPosted: Mon Nov 30, 2009 1:46 am    Post subject: Reply with quote

Thanks so much for this thread. Wow!!!

Jules


PostPosted: Mon Nov 30, 2009 1:57 pm    Post subject: Reply with quote

lulalake wrote:
Thanks so much for this thread. Wow!!!

You're welcome, Jules.

Here are a few more pictures from the less visited areas of Bandar Seri Begawan taken with the Cooke Kinic, the wow lens which has instantly gained the rank of favorite of the moment on my E-P1, eclipsing every other lens:























Cooke Kinic slideshow: http://abbazz.zenfolio.com/p980496762/slideshow

Cheers!

Abbazz


PostPosted: Mon Nov 30, 2009 2:05 pm    Post subject: Reply with quote

Thank you for the new pictures.
The more I browse in this thread, the more do I want a Micro 4/3, too.
Might be useful as back-up body for vacaciones, too. Good excuse to get one... one day.

Klaus


PostPosted: Mon Nov 30, 2009 2:10 pm    Post subject: Reply with quote

exaklaus wrote:
Thank you for the new pictures.
The more I browse in this thread, the more do I want a Micro 4/3, too.
Might be useful as back-up body for vacaciones, too. Good excuse to get one... one day.

Thank you for the kind comments, Klaus.

You know resistance is futile Wink ...

Cheers!

Abbazz


PostPosted: Mon Nov 30, 2009 2:47 pm    Post subject: Reply with quote

Great pictures indeed, thanks Sebastien!

That Kinic indeed shines whenever somthing is right centraly located in the middle of an image
so that swirly fuzzyness enhances that; with landscape shots or architectural etc., "flat"
subjects it is a different situation and I prefer more the rendering a Tevidon for instance will
give with high sharpnesss + contrast and flatfield over the whole image. I get a bit burnt out
if I see too many swirly images after another.... Wink


PostPosted: Mon Nov 30, 2009 3:01 pm    Post subject: Reply with quote

Not really an "odd" lens, but the famous slim CZJ Biotar 1.5 7,5cm (75mm) red T on Lumix GH1, shot fully open:













and I also had the Kinic with me, perfect for that subject:





PostPosted: Mon Nov 30, 2009 11:39 pm    Post subject: Reply with quote

kds315* wrote:
Not really an "odd" lens, but the famous slim CZJ Biotar 1.5 7,5cm (75mm) red T on Lumix GH1, shot fully open

Thank you Klaus for these refreshingly straight images. You know how to make the old Biotar sing.

Cheers!

Abbazz


PostPosted: Tue Dec 01, 2009 12:05 am    Post subject: Reply with quote

Thanks Sebastien, well it is the one (my 2nd) I have for sale here on the forum and the proof that it delivers!!


PostPosted: Wed Dec 02, 2009 1:08 pm    Post subject: Reply with quote

Abbazz wrote:

You know resistance is futile Wink ...

Cheers!

Abbazz


I know...
Klaus


PostPosted: Mon Jan 18, 2010 3:34 pm    Post subject: Reply with quote

Here are some of my favorite shots from my 1week old C-mount gear.
GF1, Angenieux 25mm f0.95 (crop to 50mm in M43)

[img]http://farm5.static.flickr.com/4001/4278684253_84b3b168de.jpg
stealth street photography[/img]


my new playmobil photography model


indoor shot of cookie monster ride at shopping mall


colleague at cafe


flora shots near workplace....would love to shot more flora but need to find time[img][/img]


PostPosted: Mon Jan 18, 2010 3:37 pm    Post subject: Reply with quote

eooojj wrote:
Here are some of my favorite shots from my 1week old C-mount gear.
GF1, Angenieux 25mm f0.95 (crop to 50mm in M43)

[img]http://farm5.static.flickr.com/4001/4278684253_84b3b168de.jpg
stealth street photography[/img]


my new playmobil photography model


indoor shot of cookie monster ride at shopping mall


colleague at cafe


flora shots near workplace....would love to shot more flora but need to find time[img][/img]


A reply to make your pictures visible (anti-spam measure; a new user's first post can never contain pictures).

Welcome to this forum, BTW!


PostPosted: Mon Jan 18, 2010 3:39 pm    Post subject: Reply with quote

Hi Spotmatic,
Thanks, thats ingenious and very kind of you.
I feel so welcomed already! Smile
Thanks again.
Cheers,
Ed Forrest


PostPosted: Mon Jan 18, 2010 3:40 pm    Post subject: Reply with quote


stealth street photography


PostPosted: Mon Jan 18, 2010 3:46 pm    Post subject: Reply with quote

Now that I have a GF1, I need to start looking into all these weird lenses Smile Obviously, I'd kill for a nice f0.95 lens... if I could ever come across one... I am eyeing a Robot/CZJ Biotar 40/2 though. Anybody try one of those?


PostPosted: Mon Jan 18, 2010 6:11 pm    Post subject: Reply with quote

I decided in favor of the Schneider 1.9/40mm Xenon for Robot, which is supposed to be the better lens