RZ67 Pro II Diopter...-1.5 or -3 for portraiture?

[moodlover]

I have the standard waist-level viewfinder with the -1.5 diopter but the glass broke off the plastic cause I pushed too hard. I have superglued it back in but I dont feel too great about it knowing it could be causing a focus issue in the future.

I found a few on eBay ranging from -1.5 -2 or -3 and I was wondering which one zooms into the ground glass more? I always need sharp eyes for portraiture so I'm wondering if anyone has any advice thanks!

 

[bstark]

I think you should get the lens which matches your eyesight, since that's what these things are for. A positive-diopter correction lens would enlarge the image very slightly, but since the distance to the ground glass isn't adjustable you wouldn't be able to focus unless you actually are far-sighted. (Caveat: I may have any part of this backwards.)

If you want an enlarged image, there are "chimney" type viewfinders with built-in magnifiers.

 

[moodlover]

Thats what I read but im not sure if it matters here since I just want a much more enlarged image. I have standard 20/20 vision and I know -1.5 is the diopter most RZs come with so if I get a -2 or -3 I'm wondering if the image would be more enlarged for me

 

[williaty]

In a single-lens system like the flip-up diopters on Mamiyas, the diopter doesn't enlarge or reduce the image at all. What it does is to allow your eye to move very close to the ground glass while still being able to achieve focus. The image size is exactly the same as stuffing your face right at the top of the waistlevel finder chimney without the diopter flipped into place. Most of us are incapable of focusing our eyes on something this close to our head, so the flip up diopter gives our eyes the extra focusing throw necessary to focus on the ground glass.

Think of the diopter kind of like macro extension tubes. They allow lens to focus on something much closer than it otherwise could. However, they don't make the subject any bigger. The subject appears bigger because you stuffed the lens really close to it (thus requiring the extension tube to actually achieve focus).

 

[moodlover]

Then why do they sell -2 and -3 diopters?

 

[williaty]

Then why do they sell -2 and -3 diopters?

Because different people have different eyes.

Depending on if you're near- or far- sighted, and how severely you're near or far sighted, you'll need different amounts of diopter "help" to be able to focus on the ground glass from such a short distance (with your head right at the top of the WLF chimney). All the varying diopters do is to account for how much different people's eyesight varies from one person to the next.

 

[moodlover]

Ahh I see what youre saying, so it doesnt offer any kind of image enlargement on the ground glass and I should buy the standard -1.5?

 

[williaty]

Correct, the flip up lens offers no enlargement, it just allows your eyes to focus on something really close to your face. The assembly gets called a "flip-up magnifier" but it doesn't actually magnify anything.

IIRC, the -1.5 is the correct value for "standard" eyesight. If your optometrist has told you that your vision is 20/20 or better at both near and far distances OR if your eyesight is corrected to 20/20 with glasses that you wear while looking through the flip-up magnifier, then the -1.5 diopter is probably the right one for you. But really, you just use whichever diopter makes it easiest for your eyes to focus on the ground glass.

An easy way to experiment is to take your camera to a drug store. Almost all drug stores have a display of "reading glasses" which are simple lenses ground with solely spherical correction. They'll range from -0.5 or so all the way down to -4 diopter. Leave the flip-up magnifier out of the way and see what power of reading glasses make it easiest for you to focus on the ground glass with no eyestrain when you have your eye right at the top of the WLF chimney (right were the flip-up magnifier would otherwise be). Whatever diopter power of glasses you feel are the easiest to focus through is the same (within 0.5-sh of a diopter) as the lens you'd do best with in the flip-up.

 

[Stephen Prunier]

I have and use the standard -1.5 with my RZ. I've also started wearing my 1.50 reading glasses when looking through it. It does look sharper when I wear them. Today I plan to do a test using both methods. Personally, I don't think I'll see any differences in sharpness, but, it will remove any doubt I have. I'm not getting any older. It's just that my eye's are having trouble keeping up with me. I have the same issues with my knees and back!!!