[architorture]

love this thread!

i've been wanting something with f/1.2 forever, especially in the 55 or 58mm range. so when i saw the deal i rather impulsively went for it. can't wait to get mine.

i'd actually seen some of the previous listings by this seller and noticed the comment about using live search, but figured it was a bunch of bologna until you guys mentioned it. if it does work like it should, it'll be pretty awesome (especially since i also had a 10% off coupon from ebay).

i'll be watching this thread until mine arrives and i can add some of my own pics.

btw, that was me who snatched up the one last night (thanks to you).

(the bad thing is the live search deal is a great excuse to feed the LBA and GAS)

[Miserere]

...if it does work like it should, it'll be pretty awesome (especially since i also had a 10% off coupon from ebay).

So how much did you get it for? Did you actually have to pay anything?

[rparmar]

I think you might be my long-lost Irish brother from another photographer mother

I'll have to ask my mum about that next time I see her.

For the record I am Canadian now living in Ireland. I could be here 20 years and to the locals I'd still be a "blow-in".

And thanks for the good words! All I know is my Pentax has let me get images of stuff I only ever had floating around in my head. And let me tell you, as a poet, theorist and sound artist I have an awful lot of strange stuff floating.

This is like the Porst, and although it's a bit difficult to see, there are 8 aperture blades. And I think this guy pulled the optical formula out of his arse or copied it from the Tomioka. Either way, it's incorrect.

OK, good to know. it seemed wrong.

[John Kovarik]

Just an observation and note of appreciation to those who have contributed to this (and other threads) for greatly adding to my store of knowledge of photography, the science and the art.

Amazing how a single thread can begin to weave a wondeful (if sometimes weird) tapestry............Ha!

[Gooshin]

for the measurebators

Zenfolio | Serge Guschin | 50mm tests

cosina 55 f1.2, fa50 f1.4, super takumar 50 f1.4, super takumar 55 f1.8 and a cheapo vivtar 50 1.7

originals are downloadable, go nuts.

the rat is my #1 source of test shots, also the books are stacked diaglonaly to illustrate depth fo field increases.

i tried to focus all my shots in the book 3rd from the bottom, which also aligned with the rats eyes/ears

my own personal conclusion:

i can sell all my other 50's off, and most likely including the FA43.

that is how good i think the lens is.

[architorture]

my own personal conclusion:

i can sell all my other 50's off, and most likely including the FA43.

that is how good i think the lens is.

i only have a pentax k-55 f/1.8, and i've only had my cosina for a couple hours and only done quick snaps, but i am honestly amazed by this thing! if not for the lack of monetary value of the k-55 and the appeal of having a pentax 55mm, i agree i could sell everything else in the range (although i still want the da*55 and voigtlander 58).

on my k10d, in indoor light focus about 4feet, iso 400 i can see individual skin cells on a hand from max aperture! even better though is how amazingly smooth the transition from in-focus to out-of-focus appears - it's just a perfect blended gradient. f/2 and 2.8 are sweet too.
@ f/1.8 as above (exif should be intact):


100% crop:


the body is great too, mostly metal and very solid. the only nit-picks so far would be lack of a-setting and some purple fringing on highlights at larger apertures (to be expected with such a lens).

[sharko]

I've only had it for a day but it is a great lens though I also did notice purple fringing during the day even after stopping down to f/5.6 and it seems to have an even longer close focusing distance than the M 50 f/1.7. My FA 50 has been neglected ever since I began getting manual focus 50's and I was disapointed by it's low light auto focus ability. Pentax M 50mm f/1.7 is much sharper, 58mm Nokton has ridiculous bokeh, and this Cosina lens is faster and also has very nice out of focus highlights.

[Gooshin]

purple fringing can be post processed away

[jgredline]

Hmmm, missed this thread. I for one am very happy with Cosina. It amazes me at how useful F/1.2 really is. + it is cool....

[architorture]

so, i went out for this lens' first extended testing session yesterday. over all, i am still very positive about this beauty.

I have some observations/developing conclusions i was hoping i could get some feedback/corroboration on.

1) my lens (at least) appears to focus past infinity. when focused at the infinity stop distant objects are not sharp. if i focus bracket towards closer focus, one of those shots will be very much improved. this is based on multiple tests, one of which was on a tripod (2s self timer, cable release, on stone paving) with a scene 1 mile away (and same shot taken with and compared to pentax k-55mm f/1.8).

2) it is not really f/1.2!? this is only based on one unscientific test i did aperture bracketing and changing shutter speed to keep exposure constant (this was to compare in-focus to out-of-focus rendering, etc.). from f5.6 --> f2 the overall exposure stays even, but then @ f1.2 the scene was much darker (2/3rds + ev comp needed in processing to make it even, actually). i am pretty sure the light level did not change, and the shutter speed in the exif is 1-stop different. f2 - f1.2 should be 1 1/3 stops difference, but this particular sequence would indicate that the largest aperture on the lens only lets in as much light as f/1.8 (if my math is right).

3) focuses backwards compared to all my other lenses. not a big deal, but a little annoying.

anybody noticed these things, too? if you really think pics are necessary, i can upload them, it's just it is a pain to post them in the thread as links to the original.

[jgredline]

I have not noticed anything that you have noticed. But then again I am only concerned about the images I get. I am not a pixel peeping measurabator and I am very happy with my lens.

[Gooshin]

the glass element is some 5mm if not wider than a 1.4 lens, the rear element is physicaly the largest i have hed in my hand

now i should try to test this...

[thePiRaTE!!]

so, i went out for this lens' first extended testing session yesterday. over all, i am still very positive about this beauty.

I have some observations/developing conclusions i was hoping i could get some feedback/corroboration on.

1) my lens (at least) appears to focus past infinity. when focused at the infinity stop distant objects are not sharp. if i focus bracket towards closer focus, one of those shots will be very much improved. this is based on multiple tests, one of which was on a tripod (2s self timer, cable release, on stone paving) with a scene 1 mile away (and same shot taken with and compared to pentax k-55mm f/1.8).

2) it is not really f/1.2!? this is only based on one unscientific test i did aperture bracketing and changing shutter speed to keep exposure constant (this was to compare in-focus to out-of-focus rendering, etc.). from f5.6 --> f2 the overall exposure stays even, but then @ f1.2 the scene was much darker (2/3rds + ev comp needed in processing to make it even, actually). i am pretty sure the light level did not change, and the shutter speed in the exif is 1-stop different. f2 - f1.2 should be 1 1/3 stops difference, but this particular sequence would indicate that the largest aperture on the lens only lets in as much light as f/1.8 (if my math is right).

3) focuses backwards compared to all my other lenses. not a big deal, but a little annoying.

anybody noticed these things, too? if you really think pics are necessary, i can upload them, it's just it is a pain to post them in the thread as links to the original.

I can comment on 1) the infinity focus issue.

I initially found on my VL125/2.5 the same result, and was at first diappointed. I noted the same effect with the 180/4 to a much lesser degree.

Then, my first copy of the T*25 Distagon wouldn't go far enough to get to infinity properly and I realized it could be worse, heh.

In the end, I speculate that lenses designed for use across various cameras that might have mild variations in registration distances, might over correct for infinity to make sure they get there across the mount - just a guess, but I'm rather grateful for it on the VL after my T* experience.

I also noted that manually focusing makes this trait more obvious. In an age of AF, it isn't as noticeable. My former Sigma 15/2.8 mildly over corrected, but at least it was marked to show you had passed infinity. I've tested all my lenses to be sure that the end of the throw was indeed its sharpest infinity point and its a mixed bag. The VL125 was the most over-corrected, the Zeisses all seem lined up right at the end, as is my FA31. I have a shadow of a doubt with the 58... I usually test this as infinity gets farther away... I haven't decided if I just torture myself with that one yet, lol.

[architorture]

I have not noticed anything that you have noticed. But then again I am only concerned about the images I get. I am not a pixel peeping measurabator and I am very happy with my lens.

no need for name calling! i am also concerned about the images i get, and if my images focused at infinity are a blurry mess, i am that much more concerned

[architorture]

it could be worse, heh.

i agree it is much better for the lens to go too far than not be able to get there.