Crop ratio of C-Mount lens on MFT cameras?

[kenri_basar1]

<p>Hello,<br>

I know that 35mm lenses has crop factor of 2x on MFT cameras so my question is what is the crop factor of C-Mount lens on MFT bodies?</p>

<p>I am generally weak in maths (and logic) so kindly help me with simple answer.</p>

<p>Thank you in advance.</p>

<p> </p>

[Jochen_S]

<p>Sorry, "it depends" is the only correct one coming to my mind.<br>

Crop ratio refers to the 35mm stills camera format. Some C-mount lenses were made for that so you can use the crop factor 2 for a 35mm Summicron no matter if its in M or C mount.</p>

<p>Now the nasty part: C mount was used for (CC)TV cameras and small cine formats like 16mm, maybe even 8mm too. Some of these are even smaller than MFT and its not unlikely that some of the lenses for them won't render an image filling your entire sensor. - If thats the case you'll have to crop something out of your MFT image to get a rectangular result without dark corners.<br>

Bottom line: crop factor is 2, but maybe you'll have to crop further though.</p>

[kenri_basar1]

<p>Thank you @Jochen Schrey for your reply.</p>

[jamie_robertson2]

<p>It doesn't matter what type of lens you use, the 2x factor ALWAYS applies. Whatever the focal length of the lens, just double it to get the equivalent focal length in 35mm terms.</p>

[Uhooru]

<p>Jamie +1</p>

[bill_pearce2]

<p>These answers don't get to the point, I think. Yes, the difference between 4/3 and 35 mm is 2x, but the meat of this question is will a C mount lens cover a 4/3 frame.<br>

Having once used a lot of C mount lenses professionally, albeit years ago, I can't imagine that any C mount lens would be used on a 35mm camera. The chances of it covering all the frame are 0. I would be surprised if a c mount lens could cover a 4/3 sensor, and it's likely the results would have to be cropped to a square. A 16mm frame is really tiny, about the size of my thumbnail. much like the sensor in small compacts. So, if you have some C mount lenses you want to play with, more power to you, there were some really good lenses made for that format, but just have fun.</p>

[Uhooru]

<p>Ahh, my bad, I was thinking he was referring to APC mount lenses. I have a friend who uses these old cinematic lenses on her 4/3, and she loves the effect, but yes your right these lenses will not cover the full area of the M 4/3 cameras, however, if you look on eBay there is quite a trade in both adaptors for these lenses to M 4/3 or lenses where the mounts have been so modified. They tend to be very inexpensive, so it could be fun to play around.</p>

[bill_pearce2]

<p>Actually, the world of C mount lenses is a minefield. There are many fine ones, made by German manufacturers that were used on 16mm movie cameras used by journalists, but as one who shot TV newsfilm in the day, I can assure you that condition could be a challenge. Others that were not so well made were ones designed for surveillance cameras with a 1" vidicon tube that were of predictably low quality that were sold for a very low price.<br>

One of the nicest I ever used was a angeniux 10x zoom, but it was very long and skinny, and not designed for hand holding on cameras like today's m4/3.</p>

[Uhooru]

<p>"minefield" yes, and you see al lot of these made for "cctv" for around $10-20 USD. I would think a bit of research into these types of lenses would be needed, but I do know that some people are using them and enjoy very much, especially for doing video on m 4/3s cameras.</p>

[bill_pearce2]

<p>That's not much less than the price new in the box. Just remember the old saying, "There's no accounting for taste."</p>

[Uhooru]

<p>When I say using "them" I'm not referring to the CCTV stuff, I mean Angeniux, and she also has a Leica Hector and a couple other lenses I've never heard of. Yes, taste of course. She likes them because of some low light capability, but to me they make everything ugly orange when she takes video indoors. On my 4/3 I'd just rather use the lenses made for them, or larger format lenses adapted to it, such as M mount lenses.</p>

[bill_pearce2]

<p>At least she's starting with the best lenses in the format. The cctv stuff was never anything but junk. </p>