This came up yesterday in another thread but it didn't really get much attention. The question was if the 100/2 exhibited PF (or birefringence) outside with high contrast backgrounds? Others mentioned the 85 had this problem but it went away narrower than f/2.8, so I am wondering what the true story is for these gems.
The reason I ask is that I am looking for one of the 2 to fill a gap in my arsenal primarily for low light performances and occasionally as a lightweight vacation tele. I've used the 85 before for indoor performances and outdoors just goofing around, and it is a rgeat piece of glass. When I was using it outdoors I didn't notice any PF (went back to check), but I had it stopped down a little.
The 85mm will show PF at wide apertures. I notice them a little even when stopped down a bit past f/2.8. It's a bit of a let-down but it's not enough to have me worrying about it. This is one of my favorite lenses.
If you need a lens that will not show any PF then the 100mm macro is the way to go.
I will post some examples tonight or tomorrow morning.
I don't have many left, since I deleted most of them, but I believe I still have at least two pics with a high amount of PF that will serve as an example.
Not only the Canon 85mm f/1.8 has that problem, even the 85mm L I&II and the famous Carl Zeiss f/1.2 60th Anniversary all do at wide open aperture. Indeed, the problem is reduced to a minimum at 1-stop down. At about f/1.8-2.0, these faster lenses show less PF than the Canon 85 f/1.8 wide open, because of the somewhat closed aperture. Does the Canon 100mm f/2.0 have similar PF problems? Yes, it does, although form what I can tell less than the Canon 85mm f/1.8.
BTW, it is not only outdoors, it is ANY high contrast area when shot with large apertures. The 85/1.8 and 100/2.0 are great for indoor sports, but I have seen many examples posted where you have severe PF around blown or nearly blown highlights in sports images. Hockey helmets are notorious, as the bright lights create blown highlights on dark helmets, and white helmets are often problematic.
That said, this issue is easily fixed in software and should not preclude you from enjoying either of these fine lenses.
Wow: these 85mm "vs" 100mm discussions have been common of late...
I'll repeat what I've said in other threads: I owned the 85mm (f/1.8) and found it to have a high to very high level of PF...My first copy, which was a dud, was terrible in this regard. The second copy was notably better, though still too affected for my tastes (mainly candid work).
I cannot persuade you that the 100 f/2 is perfect, because it isn't. However, I experience far fewer problems with PF 1) indoors, 2) above f/2.8, and 3) wide open than I did with the 85mm. Further, the PF that I do encounter is much more easily eradicated than it was on the 85.
As an example, I was out shooting eastern VA's, uh, "lack" of autumnal spendor the other afternoon and managed to isolate a few bright yellow leaves against an overpowering sky (perhaps poor composition, but I hadn't a latter to climb in order to better my perspective!). Shot at f/3.2...not one bit of PF. Shooting some mushrooms (orange!) in a similar environment yielded very little PF wide open, as well.
The 100 f/2 does what I want it to, when I need it to: but so does the 85, for many folks. Try 'em out and keep the one that works best for you: that's what matters!
DrPablo wrote:
I have blue-yellow fringing at all apertures with my 85 f/1.8, but it's generally not a problem except with high contrast subjects.
Purple fringing is a different matter entirely. If you have a a two color fringe such as blue/yellow, or a red/cyan area near the edges of the image, that is CA, and can be fixed with many of the CA software tools. It means the colors are out of register, and one of the channels needs to be resized. CA is typically null in the middle of the frame, and gets progressively worse as you move out towards the edges. Most CA is of the red/cyan or green/magenta variety, with Olympus usually giving the rarer blue/yellow fringe.
The purple fringe here is a distinct purple edge on the edge on either leaves against skies, or against speculars by chrome, or window areas, or other strong highlight areas. It is the same in the center as it is on the edges.
