As I already mentioned, I’ve slapped the little Cosmicar/Pentax 25mm f/1.4 C-mount lens onto my E-P1 again — and what can I say, I’m as thrilled again by this lens as I was the first, the second, the third and all consecutive times I used it. On the E-P1, it’s simply magical!
There’s something about the colours the way the lens renders them combined with the way the E-P1 reproduces them that make this special combination so unique. From all the lenses I’ve used on the E-P1, this is the one I enjoy the most — and yes, its optical imperfections have a good deal to do with that!
But before I lose myself in ongoing ravings about this little, inexpensive gem, let pictures speak! 
Olympus E-P1 + Cosmicar/Pentax 25/1.4 @ f/1.4, 1/100 sec, ISO 250
Olympus E-P1 + Cosmicar/Pentax 25/1.4 @ f/2, 1/320 sec, ISO 200
Olympus E-P1 + Cosmicar/Pentax 25/1.4 @ f/1.4, 1/125 sec, ISO 200
Olympus E-P1 + Cosmicar/Pentax 25/1.4 @ f/1.4, 1/125 sec, ISO 200
Olympus E-P1 + Cosmicar/Pentax 25/1.4 @ f/1.4, 1/100 sec, ISO 1250
Olympus E-P1 + Cosmicar/Pentax 25/1.4 @ f/1.4, 1/200 sec, ISO 200
Olympus E-P1 + Cosmicar/Pentax 25/1.4 @ f/1.4, 1/1250 sec, ISO 200
July 8th, 2011, 9:52 pm | 
You must be having fun reigniting my lust for lenses, aren’t you?
-Chris Gampat
Editor in Chief
The Phoblographer
PS: I’m a big fan
Haha
I’m just paying back the online community for what they did to me 😉
P.S.: Thanks for the huge compliment!
Always a pleasure good sir.
Nice pics, nice lens! (I have one 😉 You wouldn’t happen to know the front thread size for attaching a filter? Thank you.
Thanks! I only use it every so often, but it’s always great fun! The filter thread diameter is 27mm – I know because mine came with a polarizer filter attached, which I’ve never used so far. Should try it next time. Are you using yours on an MFT camera, too?
Yes, the Panasonic GH2. I do almost exclusively video, so these manual lenses are great. It has really nice color-rendition, as you said, it’s sharp and I love how smooth focus and aperture works. And now thanks to you I can finally buy a stepup ring to attach a filter..! Do you have the silver one as well?
Silver? I wasn’t aware there was also a silver version. No, mine is black, it’s essentially the one you can get new from B&H, only a few years older.
http://www.flickr.com/photos/astroman-photo/3731981452/in/set-72157621629205806/