ovredal73 wrote:
Dear Leon, I actually have a Pentax K - EOS sitting around, but I am surprised that it is possible to switch between these different adapters...? It could then actually be any of these...?
I had to look up flange on wikipedia to figure out what you mean by that word, but from what I can understand, almost all adapters will have a flange...?
If you look at the first image on the railway wheel here, all adapters have this kind of flange...? Am I completely misunderstanding?
The flange we are speaking of is on the inside circumference of the adapter, right next to the M42 threads. They put it there to push the aperture pin in on M42 mount lenses.
Ah, now I understand, and the fotodiox I linked to earlier then seems to have this kind of internal flange. Am I right? Not a big deal to get rid of, but as you say - more work.
EDIT: No sorry - looked at the wrong one - the fotodiox does not have the flange. Will get that then. Or maybe a backup Pentax adapter.... Hmmm.....
Well wont keep you anymore - thanks, Paul and Leon!
You cannot trust the photos. I have ordered ones that look unflanged and received flanged.
The thickness is irrelevant, because you'll be sanding the shim to reach infinity anyway. Well, if it is thinner it just means less sanding of the shim, I guess.
apras wrote:
how about the 50mm 1.2 rokkor? as good as the 58mm??
It is not easily converted in the manner described in my howto.
Also, the only thing proven by the article that Leon posted the link to is that the sample of the 50/1.2 tested was minutely sharper than the sample of the 58/1.2 tested. I believe this is simply a matter of sample variation. The bokeh on the 58 is undoubtedly better (on all samples )
I have done the second convertion of the Rokkor with metal ring - so it is even possible to get past infinity focus and still do not hit the mirror on 5D.
Ok, for the info here is sort of quick test of Rokkor/Zeiss/Canon/Russian Helios 40-2 on Canon 5D
ovredal73 wrote:
Dim.ka - good to hear that your metal ring version does not hit the 5D mirror
The version of lens makes no difference. They all protrude beyond the mount the same amount. Mechanically they are all identical, except for the focusing ring.
I would be very wary of assuming that you will have the same results as Dim.ka.
Thanks for the warning, I will be careful, of course. I will sand down very patiently to find the right distance.
However it must be possible to assume that some basic physical factors are the same, when the camera and the lens are the same? I mean; both items (rokkor metal version and my 5D) have originally been produced precisely in thousands of copies to fit perfectly with a variety of lens/camera combinations?
Well Paul, the methodology of that test wasn't half bad, so I don't see why we should disregard the results (which comes across as a little unecessarily defensive).
Nowadays nothing is general concensus because no one can ever test a big enough amount of samples for anything to be universally representative (a bad CZ21 can be trumped by a good EF 16-35II but *generally* we believe all CZ21 are better than all 16-35, no?), but realistically at a certain point in time we gotta take someone's words for it, and I'm grateful there are people out there who are willing to use their own time to "test" and freely publish results for the benefit of the community as a whole.
And I won't be disappointed or skeptical if the Rokkor 50/1.2 came out "slightly sharper" (my words used in last post) than it's old brother 58/1.2. It came out later with a different design, with better spherical abberation correction (less "glow" for wide open shots), and 50mm lenses are sharp, 58mm may be different. Nikkors or Zuikos or Pentaxes are not much different, later versions often are slightly better resolving, evolutionarily, I don't see why it shouldn't apply to Minolta.
My 58/1.2 is perfectly usuable wide open and with proper processing it can show very respectable amount of details even wide open, even if it has a bit "glowing" I like the look, in this package there are 3 cropped full size JPEGs I shot with my 58/1.2 and properly processed (denoised, curved and appopriately sharpened), since they are just test shots there's nothing artistic though:
http://www.sendspace.com/file/d132gw
Regarding Dim.ka's odd mirror clearance on 5D, I think he has a magical 5D whose mirror is either ultra short or ultra receded that's all.
Sorry, I seem to be a bit slow to realize all the issues with this rokkor/5D relationship. Is it expected that I will have to shave my mirror before this combo will work? I really dont understand this; either every copy of the same lens will clear or it won´t. I cannot grasp that there will be sample variation as to how deep the lens protrudes (or variation in the 5D mirror position) I mean - this is fine machinery.
Edited by ovredal73 on May 07, 2008 at 07:05 PM GMT
Think about it, it's *gotta* be the camera. Optics/glass = precision science, that's why a lens' tolerances are much tighter than that of a mirror box in a DSLR don't you agree?
And people have tried the *same* lens on different 5D bodies, some clear, some won't. So is it the lens or the bodies? Easy conclusion.
Crazy. But I accept it if you say it is so. I would think the 5D should be as precisely manufactured as anything else.
I will just have to cross my fingers for when my time comes - in a couple of weeks...
Think about it. This is a result of a cost/benefit analysis by Canon in the design of the 5D. If Canon designs the mirror assembly to allow for larger variances it probably saves considerable cost over a 1 series body. Not only are the parts likely cheaper, but there will be less QC rejects for out of spec bodies. As long as the range of the variance still allows for all Canon EF mount lenses to work properly, everyone is happy....that is until some crazy 'alt' lens fanatics at FM come along Don't forget the 5D was designed as the 'budget' FF body.
