Originally posted by and I dont have a katzeye myself, I bought a cheaper screen, a Nikon screen that also fit the k10d. And I have had no metering problems in any metering mode, AS long as the lens is f2.8 or faster! but if it is, no problems. if its slower, then problems will occur in any metering mode, not just spot. Especially one of my zoom lenses that is f5.6 in the long end will underexpose over 3 stops. Of course dont pay too much attention to this because I believe the katz eye is different in some of these aspects. but just to make it clear, split prism does not affect af, it is great but it can affect metering, most noticably with slow lenses.
The aperture that you're talking about here is the lens's technical maximum, right -- not the aperture at which you're actually shooting the photo right now? In other words, you're okay shooting at f/16 provided the lens can go to f/2.8 or faster when you want it to?
It's a little more troubling to me to hear that shooting with fast lenses, there's no problem with metering, while shooting with slower lenses, there is. That means the effects on metering are NOT consistent. Most of the lenses I use now are f/2.8 or better:
- Sigma 18-50 f/2.8
- Pentax DA* 50-135 f/2.8
- Pentax 35 f/2
- Pentax 50 f/1.4
But there are three lenses that I still use fairly often that are slower:
- Tamron 75-300 f/4-5.6
- Sigma 10-20 f/4-5.6
- Pentax 16-45 f/4
To make matters a bit worse, I frequently use the Tamron 75-300 with a 1.4x converter, so the effective aperture at 300mm is f/8. I'm pretty sure the Katz Eye web site suggests that the "blackout" phenomenon occurs at f/5.6.
So I have two more questions.
First, am I correct in thinking that the camera will meter more or less normally if I'm using a fast lens, but that I'll have to remember to expect a bit of a hit if I'm using one of my slower lenses? Others here have said the effect is consistent, but I'm not sure whether that meant "consistent for a particular lens," or "consistent at a particular focal length," or simply "consistent regardless of lens and focal length."
Second, should I consider the Opti-Brite treatment for the Katz Eye? The Katz Eye web site is understandably non-committal about the benefits of this treatment. They sell it as an option and of course that means they have to suggest that buying a screen without this option will give you acceptable results. But I wonder if it's not worth the extra $55. Anybody have it?
Will