Cheap wide lens for my NEX3 - C mount

[David Mitchell]

Hi all,

I now have my Sony NEX-3 (thanks Hamish ), and have started ordering adaptors for different lenses, I have come across the C mount lens which is used on some Cine cameras and CCTV cameras and seems to be a common adaptor for 4/3rd cameras.

The crop factor for the NEX is 1.5 much like the Nikon D3100 I have, this usually means wide angle lenses are difficult to find due to the very small focal distance needed - eg you need an 18mm to get a wide shot.

Having a look around at some C mount lenses it seems that you can get fast wide lenses cheap, I have just found an 8mm f1.3 lens for not much - this would give me a 12mm lens if I had it on a 'full frame' camera.

I can see why for 3/4rd sensors these lenses are idea, I can focus to infinity as well on the NEX as its got no mirror in the way lol

I will show you some results once I get the adapter and lenses, I know that the image circle might be an issue, although I think its just the D mount lenses that the image circle is too small, the C mount seems to be ok I think because they are ment for the 16mm cine camera rather than the small 8mm cine cameras the D mounts are for.

p.s. Hamish - you can also get C mount Cooke lenses

 

[Hamish Gill]

Glad it arrived ok!

Yeah, many times I have thought about buying a c-mount adapter ... There are stacks of lenses out there. There is no set image circle for c-mount though as its used for all manner of things including 8mm cameras. Basically you have to be pretty clued up on the lenses to know what result you are going to get.

for example, your 8mm lens might have been intended as a telephoto lens on an 8mm camera. Normal being about 5-6mm (ish I think)

so, the image circle does matter ... A lot. You might not get an equiv of 12mm over the whole frame, instead you may get an equiv of 60mm in a tiny circle in the middle of the photo surrounded by black

 

[David Mitchell]

I have found that the 'standard' C mount lens that people are using is a 35mm f1.7 TV lens, most of the CCTV lenses are fixed but those TV lenses aren't. Seems that SLR magic sell a kit with the lens and adaptor, but I already have an adaptor coming lol

SLR Magic 35 1.7 Lens review on the Sony NEX-5 | STEVE HUFF PHOTOS

Much like my D3100, the 35mm lens will give an equivalent of around 52mm if it was a full frame camera and it seems that anything over 25mm will be useable.

I had a look at the D mount lenses but those won't really work due to the flange distance being even smaller - so I can't use my Bolex B8 lens then

Its ok though as I think I will look into getting this 35mm f1,7 lens, it doesn't really get very sharp but gives a nice effect which is good. Also if I find something around 80mm it would be good for a portrait sort of lens, its fairly soft in places which would lend itself well to portraits - you can get 3" lenses which would be perfect.

 

[Hamish Gill]

If you want to use d mount lenses with any success the only option is the Pentax Q ... They are down to about £60 body only now, I've been watching them on eBay for about a year now. When they get to £50ish, I'm goin to get one and mount the lenses off my bolex

 

[David Mitchell]

It would be interesting, although it might be cheaper for me to just get a C mount lens than to get a whole new camera lol

 

[David Mitchell]

I have a 35mm f1.7 lens coming, seems that the 25mm is ok for the 4/3rd cameras, but the NEX sensor is slightly bigger so I would need a 35mm which is fine as its the same as my D3100 difference is that I can buy 10 C mount lenses for the same cost as the single 35mm F1.8g lol although I know which one is sharper!

 

[Pete Askew]

How about a bit of card and a clear marble! It's be wide!!

 

[David Mitchell]

How about a bit of card and a clear marble! It's be wide!!

I have seen people use those peephole optics from front doors as a fisheye

The lens has yet to arrive but will do soon I guess, I think that the 35mm f1.7 is ok for my sensor, I am also looking at the 25mm f1.2 as well (most of the 25mm lenses are f1.4) the image circle might be a bit too small though but I might see anyway.