GH1 test with C-mount Zoom Lens - So far so good!!

G

gmoe

Well-known member
Hey guys I've started a new blog to help folks out who are GH1 users and to document my tests, discoveries, and experiments.

You can check out the first tests I'm doing here with a c-mount zoom lens.

http://www.componentgeek.com/
 
Good article but I can't find where you mention which C Mount lens you have?

What's the focal range of your TV zoom lens, and what speed? Looking forward to seeing footage.
 
Thanks commanderspike. There's some footage already posted on the blog with tests using compressor as pull down as well as neoscene. Thought it would be valuable info. for those who are interested to use tv and cine zoom lenses on the GH1.

I'll be posting pics and the name of the lens shortly.
 
Strange that you don't mention which c-mount lens you're using. What's the point of directing people to a test of something but you don't tell them what you're testing?
 
Sorry I've been thrown into doing Pegasus II testing and had meant to reveal the lens in my blog.


It is the..Angenieux Zoom Lens F2.2 17-68mm in C-mount. The tests were done with both a Type L2 / Type L3 zoom.
 
Long delayed but just thought I'd add my two cents on some c-mount zooms particularly the Angenieux zooms

http://www.componentgeek.com

I'm still doing some early testing but I got my Schneider-Kreuznach Variogon 1:2/18-90 C-Mount from the shop. Here's some casual footage I shot on vacation. Will be posting some more test on this lens later this week.

http://vimeo.com/6463987
 
gmoe,

what adapter do you use? do you have to machining the back of your lenses to have an infinite focus?

so, in your personal experience, what c-mount lens you recomend
 
what adapter do you use? do you have to machining the back of your lenses to have an infinite focus?

so, in your personal experience, what c-mount lens you recomend
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So far I've been testing C-mount Zooms-


The Schneider-Kreuznach Variogon 1:2/18-90 can achieve infinity focus, for longer reach you start to see some softness if you are shooting subjects off to the distance. For the shorter focal range it seems to retain a nice bit of sharpness and a nice bokeh. This lens does not need machining.

The Angenieux Zoom Lens Type L2 or Type L3 F2.2 17-68mm does not have infinity focus, it's just a little hair off- for landscapes this is probably not the lens for you but for shallow DOF stuff this works nicely. My lenses are currently being over hauled and I could get infinity focus but then it would sacrifice my close range focus. I wouldn't machine the back of the Angenieux's.

The Kodak Cine Ektars are wonderful lenses and some here on the forum already have them and shoot with them. They don't need machining and have a wonderful bokeh. Those who I've talked to who were familiar with the manufacturing process of Kodak Cine Ektars say that Kodak was trying to compete with the german glass manufacturers so they really out did themselves at the time and made some really nice glass. These lenses have jumped up in price unfortunately because of the GH1. Wollensak cine lenses are also nice but because of the small size are a little hard to focus with. These lenses are of course better for fun still photos. The cine ektars are great to focus with. When I get my prime set back I'll be posting some samples.


Also, the Computar 25mm F/1.3 if you can find it is a really good lens. Mine is currently being machined. You can pop a cheap wide angle adapter on this lens and get some real nice results. This lens and ektars above 25mm fill the image sensor of the GH1. The other zoom lenses I've mentioned must have the 2x digital zoom engaged to avoid the "peephole effect" as most have posted here on the forum.

I also have a few Fujinon and Computar TV lens zooms that are f/1.2. They definitely need machining and have that TV lens look but as of now are limited to use for macro work and do not have infinity focus.

I'm also considering taking a look at Senko particularly the Senko 25mm F/.95. There are a few G1 users who have gotten great results with this lens although it is a little shy from filling the sensor, it is similar to the Navitar 25mm .95 but a little cheaper in price.
 
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gmoe, big thanks for your information..

i do have a computar 12.5mm f/1.3, after read all your story, i will machining mine..

it's nice to have a camera that you can play with so many lens variety..

lookin more for your story
 
Gmoe,

It might be worth mentioning to your readers that Extended Optical Zoom is just windowing the sensor, effectively lowering the number of pixels used to create the image by about 75%.
 
Extended Optical Zoom only works with still photos as well; if you're wanting to use it in video it doesn't work, only "digital zoom" works, and it results in a massive reduction in resolution.
 
It might be worth mentioning to your readers that Extended Optical Zoom is just windowing the sensor, effectively lowering the number of pixels used to create the image by about 75%.
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Thanks for that fine tuning will make that adjustment and post this for my readers.

Extended Optical Zoom only works with still photos as well; if you're wanting to use it in video it doesn't work, only "digital zoom" works, and it results in a massive reduction in resolution.
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Correct Barry, I had meant digital zoom working in creative motion picture mode.

I totally hear and technically understand the resolution loss issues with the 2x digital zoom engaged on the GH1 but with the right lighting and with a stabilizer, the degradation in 2x digital zoom seems to hit more on the higher focal ranges from my initial testing with the Angenieux and Schneider zooms, at the lower focal ranges I'm still getting some very nice usable footage with these lenses. So despite the resolution loss, I think it's really just a kick to get these old lenses working and getting some nice footage with these older lenses.
 
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