C-mounts: Anyone know about these obscure ones?

[raydeng]

I don't want to add to the c-mount madness, but I'm seriously considering these lenses, but can't find *anything* about these lenses.

Can anyone weigh in on (1) coverage; (2) if it can fit the Hawkpeng adapter and (3) does it need to be modified to reach infinity?

Please don't post (1) snide remarks (if you're a c-mount pro) or (2) the google spreadsheet doc, which I've perused many times.

The lenses in question are:

1. Cosmicar 12mm f1.2
2. Cosina TV 12.5mm f1.4 (I saw this on the c-mount blog but can't find anything about it)
3. Soligor 25mm f1.1
4. Kern Switar 16mm 1.8

I mostly want a wide fast prime (like everyone else) that has decent coverage. I've seen some samples of the Kern Switar 16mm 1.8, and it seems as if the coverage is decent (for a c-mount wide), but still vignettes significantly for my tastes.

Any input would help. Thanks so much for the wealth of information, GetDPI community!

 

[laptoprob]

I don't think anything wider than 25mm will give full m4/3 coverage. Some 25's do, others don't. Or to some extent. My Pentax Cosmicar 25 vignettes slightly, but I use it on 2/3 image ratio. That solves the problem.
My Meopta Largor 12,5 gives almost a full circle. But it is fast, so if I want it for low light, I can crop a rectangle if needed.

 

[RichA]

I don't want to add to the c-mount madness, but I'm seriously considering these lenses, but can't find *anything* about these lenses.

Can anyone weigh in on (1) coverage; (2) if it can fit the Hawkpeng adapter and (3) does it need to be modified to reach infinity?

Please don't post (1) snide remarks (if you're a c-mount pro) or (2) the google spreadsheet doc, which I've perused many times.

The lenses in question are:

1. Cosmicar 12mm f1.2
2. Cosina TV 12.5mm f1.4 (I saw this on the c-mount blog but can't find anything about it)

Likely the same as the 12.5mm f1.4 Cosmicar, some hard (actual cut-off) vignetting on the periphery which means once cropped, the image is that of a 14-16mm lens.
IMO, you are better off going for a newer lens, because the coatings will make a difference, especially wide open.

 

[Photomorgana]

I only had experience with Switar 16/1.8 and the coverage is not very good, sorry. When I was trying to fix the focusing issue I had with my copy, I broke the helicoid and now I have the lens in constant extreme macro position (around 2" I think). The good thing is that you don't have the vignetting problems when lens is in macro position. Yes I can't go to infinity, but I can't say it was usable anyway, since manual focusing was tought to see due to the large vignetting.
Generally stay away from c-mounts that are wider than 25mm, just like Laptoprob said.

 

[wjlapier]

I think to go fast and wide, and full coverage, one need to look at arri lenses in 35mm format. Spendy, but might be better than trying all the c-mounts that vignette. I'm no longer chasing the c-mounts, and if I knew then what I know now, I might have gone the arri route instead--35mm not 16mm.

 

[petermcwerner]

I think to go fast and wide, and full coverage, one need to look at arri lenses in 35mm format. Spendy, but might be better than trying all the c-mounts that vignette. I'm no longer chasing the c-mounts, and if I knew then what I know now, I might have gone the arri route instead--35mm not 16mm.

I totally agree, but be careful of their condition when you buy on ebay. Let me add that one can find some great 35mm cine lenses in Cameflex mount that are usually less pricey than in Arri mount. The problem is the m43 adapter. I do not know of any existing Cameflex adapter and had one custom made. See examples in this thread of mine: Kinoptik 25mm/2.0 on the G1.

I would gladly buy a few more Cameflex adapters, because changing lenses on mine is quite bothersome.

 

[kds315]

I have Cameflex adapters made for m 4/3.

Contact me if interested.