02-04-2014, 09:12 PM
Hello. Just joined but have often looked around. Love the lens tests and of course the forum. I am a long time Olympus user in California who is transitioning to mostly micro-4/3 at this time. I'm using my 4/3 lenses on the OM-D cameras (got the -5 and the -1) and even some old Zuikos. Gotta say these cameras are the creme de la creme. I'm also building a collection of m.Zuiko lenses for use without any adapter. As of now I have the little 12-50 which came bundled with the E-M5, and when I bought the E-M1 I also purchased the 12-40 on the rebate deal and sprang also for the 75 F/1.8 Both these lenses are extremely well done.
Now my question concerns the 75 F/1.8 It is a truly luscious lens, beautiful and smooth to operate. I haven't done much with it thus far but I did do some star images, star tests at F/2 and the results leave me a bit at a loss. Most everything about the results are fantastic - sharpness across the field, NO Coma, great resolution etc. However, there is a lot of chromatic aberation - purple mostly but some blue fringing around bright stars. The tests herein show very little CA. I also tested the 12-40 at 40mm and see virtually no CA with that zoom, which is in line with the tests results here.
So I am wondering - do I perhaps have a bad sample of the lens? I think I might be able to swap it for another as I bought direct from Olympus and they always treat me well. But I don't want to send it in just yet.
I wonder if I could post the test image, might someone here give a look and an opinion? I can say that the CA I saw with the 75 is on a par with my old Zuiko 90/2 macro in the same test and actually worse than an old 50/1.8 MC Japan lens but that one had abundant COMA so is fairly useless for this application.
I attached a crop of about half the 75mm image here [ATTACHMENT NOT FOUND] which should show the CA pretty well. I also attached a tighter crop from the 12-40 at 40mm [ATTACHMENT NOT FOUND] showing appx the same area and little to no CA.
I'd be very interested in any comments and, of course, especially be interested in any interest from the lens testing folks.
In any case, glad to be here and will talk later.
Now my question concerns the 75 F/1.8 It is a truly luscious lens, beautiful and smooth to operate. I haven't done much with it thus far but I did do some star images, star tests at F/2 and the results leave me a bit at a loss. Most everything about the results are fantastic - sharpness across the field, NO Coma, great resolution etc. However, there is a lot of chromatic aberation - purple mostly but some blue fringing around bright stars. The tests herein show very little CA. I also tested the 12-40 at 40mm and see virtually no CA with that zoom, which is in line with the tests results here.
So I am wondering - do I perhaps have a bad sample of the lens? I think I might be able to swap it for another as I bought direct from Olympus and they always treat me well. But I don't want to send it in just yet.
I wonder if I could post the test image, might someone here give a look and an opinion? I can say that the CA I saw with the 75 is on a par with my old Zuiko 90/2 macro in the same test and actually worse than an old 50/1.8 MC Japan lens but that one had abundant COMA so is fairly useless for this application.
I attached a crop of about half the 75mm image here [ATTACHMENT NOT FOUND] which should show the CA pretty well. I also attached a tighter crop from the 12-40 at 40mm [ATTACHMENT NOT FOUND] showing appx the same area and little to no CA.
I'd be very interested in any comments and, of course, especially be interested in any interest from the lens testing folks.
In any case, glad to be here and will talk later.