Discussion in 'Hot Deals - Find a Great Deal? Share It Here.' started by iso640, Jan 14, 2013.
Computar 1 1 2 12 5 75 TV Video Camera Zoom Lens Computer Quantity Available | eBay
I think these do have vignetting when mount on m43...?
I think there's a thread in the adaptive lenses forum and the pics look pretty good. Granted, the one tested is 1.4, not 1.2 but I think the images provided look fairly impressive.
I just looked at some images on Flickr, and you're right, there is vignetting.
On another edit:
Found this video shot with this lens. Not seeing much in the way of vignetting. So, YMMV.
[ame="http://vimeo.com/26765402"]Computar 12.5-75mm f1.2 x GH2 (hacked) night demo on Vimeo[/ame]
Isn't there a video crop mode that a lot of people use on the GH2 with c-mount lenses? This may be one example.
Anyone pick up one of these yet? Impressions?
I recently picked up the Computar 12.5-75mm f1.2 from another seller.
Using a cheap c-mount to MFT adapter, the lens focuses just fine on my G3.
Focal range is good, 25mm to 150mm in 35mm terms.
Though the lens is designed for a 2/3" sensor, vignetting is pretty severe, even with ETC. I think for the video you posted, the video was taken using using letterboxing or something to reduce the vignetting. I'll try to post some samples.
I paid a lot less, so I'm planning to keep it and mess around with it. But for what he is asking, I don't think its worth it. YMMV.
If you are interested in a fixed focal length, this Navitar 75mm f1.3 is nice:
Navitar 75mm F1 3 C Mount TV Video Zoom Lens Japan Quantity Available | eBay
I offered the seller $129 shipped and he accepted. I got the lens today and it is quite nice. Very substantial piece of optics. No issues using it with a cheap c-mount to MFT adapter.
Just wanted to post this link to 2 images I took with the Computar (which I received today).
When getting close to the subject, there is crazy vignetting, looks like I was shooting down a barrel. However, from about 5 ft away, the vignetting lessens to the point of being tolerable.
Computar 12.5-75mm f/1.2 CCTV zoom lens - a set on Flickr
What focal points were those shot at? How does it hold up to the 1.2 at both ends (does stopping down help stop the vignetting at either end)?
What ever happened to the 4/3 c-mount lenses?
It's interesting that there are a few company's out there that manufacture C-mount lenses for c-mount cameras with 1⅓ " , 1.3" or 4/3 inch sensors. Even Kowa released a line of Machine Vision Lenses in c-mount, for 4/3 inch sensors, over a year ago IIRC. But I never see any retail sales of the lenses. Or anyone selling them for that matter.
Whats going on?
Oh.. and yea, and a quick fix for the lens OP mentioned is to use a 1.5 tele converter so you wont loose much speed, or one can just shoot in ETC mode.
I have a Computar lens in this FL and aperture, that looks exactly like this Navatar. I was thinking of selling it too but didn't think anyone would want to buy it for what I paid... it was $100 shipped.
Before buying the 12.5-75mm zoom, I had googled it to see if it was adaptable to mu43. I recall seeing a post on another forum where the author of this video, foster chen, mentions that he had modified the lens to reduce vignetting and that he also offered a modification service. Ekoe also offers a mod service for c mount lenses. If you check the various c-mount lens threads, many mention having to modify the lenses, especially the zooms, to get them to work with mu43 (just google "c-mount" and "hacksaw" or "dremel").
Many of the users of the c-mount zooms are film makers who are shooting video using hacked GH-2s.
I'm sure someone would buy it here is you posted it here or on ebay. 75mm f1.4 for $99 is a decent deal.
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