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C Mount Zoom Lenses--anyone?

wjlapier

Member
I'm curious if anyone has tried any C mount zoom lenses on their G1 yet? I came across a f/1.2 zoom lens by Fujinon that I thought of trying, but I figured I'd ask here first. The idea of a constant 1.2 aperture in a zoom is intriguing to me.

There are alot of C-mount zooms out there that would cover the wide end to mild tele at fast apertures and constant through the range. But some look like the rear would have to be machined a bit.
 

LizaWitz

New member
I know there's some issue with some lenses not providing enough field of view to cover the sensor. (Wait, I think I just used the wrong term.)

Hopefully there's a rule of thumb for being able to tell which lenses will and which won't? Though I think it depends on what the focal length (wrong term again?) of the camera they were designed for?
 
R

Ranger 9

Guest
Well, Miss Minelli, I haven't personally tried it yet. But in terms of a rule of thumb, I think it depends on the image format. Most of the wilder, wider-range zoom lenses such as that Fujinon were probably designed for video cameras, and those come in sizes designated somewhat arbitrarily as 1/3-inch, 2/3-inch, and 1-inch.

According to a chart I found on a RED camera forum (and linked somewhere in another thread) lenses designed for 1-inch video should cover at least most of the G1's sensor; 2/3 and 1/3 are quite a bit smaller and I suspect you wouldn't get much coverage out of them.

Another potential quirk: At work I used to use a broadcast-quality video camera as part of an image-capture setup. This was a JVC KY-210B, which was considered quite a nice little camera in its day. It came with an impressive Fujinon zoom lens. The instruction manual for the lens stated that the back-focus distances of video cameras are NOT standardized, so when installing the lens for the first time, you had to align it to that specific camera body via a set-screw-secured adjustment collar on the lens. Presumably you might have to do a similar procedure to mount a broadcast lens on your G1 and get it to focus to infinity.

Another unanswered question: Is a zoom lens designed to give good results on the relatively undemanding format of 525-line, standard-definition video really going to be sharp enough when used on a 12-megapixel G1? This point would make me cautious about shelling out big bucks on a broadcast zoom lens unless I had a chance to try it out first.
 

Jonas

Active member
I'm curious if anyone has tried any C mount zoom lenses on their G1 yet?
There are several threads with samples from C-mount lenses around the forum. You can search for c-mount I gather? From memory I think you have a look at the thread named "Superfast..." something.

I have a c-mount Pentax 25/1.4 supposed to cover 1" and it doesn't really reach the corners and the borders and corners are also somewhat smeared. A fun little toy though; very small and pretty sharp in the center.
 

wjlapier

Member
There are several threads with samples from C-mount lenses around the forum. You can search for c-mount I gather? From memory I think you have a look at the thread named "Superfast..." something.

I have a c-mount Pentax 25/1.4 supposed to cover 1" and it doesn't really reach the corners and the borders and corners are also somewhat smeared. A fun little toy though; very small and pretty sharp in the center.
I'm aware of the c-mount pictures and most various type PRIME lenses, but I was asking about ZOOMS, not PRIMES!! I very capable of using the search feature--thank-you ;)

I'll take the plunge for the sake of the c-mount crew and buy one ( not the Fujinon ), and report back eventually :salute:
 
I have a c-mount Pentax 25/1.4 supposed to cover 1" and it doesn't really reach the corners and the borders and corners are also somewhat smeared
According to a Schneider table, 1" CCTV lenses cover a diameter of 16mm while the MFT sensor needs 22.5mm. Most lenses cover slightly more than nominal, but the difference between 1" CCTV abd MFT is too big for most lenses. Here an extract of the table. I do not know how to make a better presentation on the forum, I hope it is readable.

mm WidthxHeight---Diameter
--- ------ ------ --------
MFT 18.0x13.55 ----- 22.5
_1" 12.8x09.60 ----- 16.0
 
I'm aware of the c-mount pictures and most various type PRIME lenses, but I was asking about ZOOMS, not PRIMES!! I very capable of using the search feature--thank-you ;)

I'll take the plunge for the sake of the c-mount crew and buy one ( not the Fujinon ), and report back eventually :salute:
I have been looking at various 16mm cine zoom lenses but they only seem to cover 16mm (if any data are published) and are very heavy and bulky compared to 4/3 lenses. 35mm cine zoom lenses would cover the whole field but be even heavier, bulkier (and very expensive).

None of them would have AF on the G1.

On top of that, they will not have image stabilization and would thus be really usable only on a tripod. What sort of lens are you looking for?

It will be interesting to hear about your experience.
 

wjlapier

Member
I have been looking at various 16mm cine zoom lenses but they only seem to cover 16mm (if any data are published) and are very heavy and bulky compared to 4/3 lenses. 35mm cine zoom lenses would cover the whole field but be even heavier, bulkier (and very expensive).

None of them would have AF on the G1.

On top of that, they will not have image stabilization and would thus be really usable only on a tripod. What sort of lens are you looking for?

It will be interesting to hear about your experience.
I think we are in uncharted territory so it is about someone's experience. What lens covers the sensor is still not entirely clear I don' think. I have a Canon 50/1.8 TV lens in c-mount. Doesn't need to be machined and covers the sensor completely at all ratios. The Canon is a c-mount, but has a larger rear element than the 25mm Switar I have, which does vignette.

The zooms got me to thinking for a couple of reasons. Some are selling for next to nothing and have very fast apertures across the whole range. It's hard to tell from pictures their size, but if using my Nikon RFer 135 ( 270/3.5 on the G1 ) is any indication it's possible to handhold. I like the primes, especially their tiny size and image quality. But for me it's about having fun with all the alt lenses on the G1.

We'll see.
 

Jonas

Active member
I'm aware of the c-mount pictures and most various type PRIME lenses, but I was asking about ZOOMS, not PRIMES!! I very capable of using the search feature--thank-you ;)

I'll take the plunge for the sake of the c-mount crew and buy one ( not the Fujinon ), and report back eventually :salute:
Well, I swear the word zoom wasn't there when I read your post. :eek:

And that's was also the reason nobody had replied; they don't like to be unfriendly. Well, I don't mind that - and so I also made a fool of myself.

sorry, and Good luck!
 
I think we are in uncharted territory so it is about someone's experience. What lens covers the sensor is still not entirely clear I don' think.
The zooms got me to thinking for a couple of reasons. Some are selling for next to nothing and have very fast apertures across the whole range. It's hard to tell from pictures their size
I agree we are in uncharted territory, am curious to hear about your experience.
I just won another, newer 25mm 1.4 Xenon that I want to use while the older one is given TLC. I wonder if I got infected by your idea of a c-mount zoom, I shall have another look on ebay
 

wjlapier

Member
I agree we are in uncharted territory, am curious to hear about your experience.
I just won another, newer 25mm 1.4 Xenon that I want to use while the older one is given TLC. I wonder if I got infected by your idea of a c-mount zoom, I shall have another look on ebay

I've bought too many lenses lately so I will offer one of my sources to you for the future. foto-hobby from Poland. I've bought lots of stuff from him/her in the past and shipping was about 10 days to US. Items were as described and the person seems to have alot of stuff you don't see often. Prices are sometimes high for some things. They accept offers sometimes so it's maybe a way to pay a little less.

As for the infection--it's those guys like butterdada and vivek that are not helping my wallet :) It's all fun though. OK, I think I'll buy that zoom lens I was looking at and call it quits for a while :rolleyes:

Robert--you got your lathe fired up? ;)
 

wjlapier

Member
Well, I swear the word zoom wasn't there when I read your post. :eek:

And that's was also the reason nobody had replied; they don't like to be unfriendly. Well, I don't mind that - and so I also made a fool of myself.

sorry, and Good luck!
No problem! Seems we are getting somewhere and hopefully we will have more information and experience to share.

Bill
 
I've bought too many lenses lately so I will offer one of my sources to you for the future. foto-hobby from Poland.
Thank you for the tip. I have bought occasionally from him. Once everything went well (35-70mm/4 Elmar R), another time a lens was quite in dire state. His descriptions are rather short and he does not show many meaningful pictures of the glass
 

wjlapier

Member
Thank you for the tip. I have bought occasionally from him. Once everything went well (35-70mm/4 Elmar R), another time a lens was quite in dire state. His descriptions are rather short and he does not show many meaningful pictures of the glass
Sorry to hear about that, Peter. That's too bad--I hope I don't run into that problem in the future. The feedback is pretty good--usually people's complaints are about the time it takes to get their item. I guess I take his word when he says mint glass. But you're right, short descriptions and usually not enough good photos.

Just curious, how long does it take to get a package from Poland?
 
I'm curious if anyone has tried any C mount zoom lenses on their G1 yet?




On the camera : Kern Macro Switar 26mm/1.1
Front, left to right: Vario-Switar 18-86mm/2.5 - Switar 25mm/1.4 - Yvar 75mm/2.8


I got the 16-86mm/2.5 Vario Switar as part of an ebay set that I bought mainly for the 26mm/1.1 Macro Switar. It mounts without machining on the G1. I did not really want it, but I was still curious to see what it could do. I was astonished at the result.




Full size picture @ 86mm /f/2.5



Crop of the same picture, slightly sharpened
 

woodmancy

Subscriber Member
I'm curious if anyone has tried any C mount zoom lenses on their G1 yet? I came across a f/1.2 zoom lens by Fujinon that I thought of trying, but I figured I'd ask here first. The idea of a constant 1.2 aperture in a zoom is intriguing to me.

There are alot of C-mount zooms out there that would cover the wide end to mild tele at fast apertures and constant through the range. But some look like the rear would have to be machined a bit.
I started this thread http://forum.getdpi.com/forum/showthread.php?t=7676 about my Canon 17-102 c-mount zoom - - a bit frivolous, but I'm having fun with the lens! This shot is at F2


Keith
 
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pentacon6

New member
Just to remind you all. Small coverage zoom lens has an alternative usage. It is micro photographic. Just reverse the lens and you should find the lens can produce extreme magnification power. A single 10 points letter can boost to full screen. Amazing!
 
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