The Fuji X-Pro1, which I've pre-ordered, needs screw-on diopter adjustment eyepieces. I'd like to order them now before the camera comes but can't figure out if I need the + or the -
Here's my dilemma -- logic and the empirical evidence are clashing and I wonder if you all can figure out what's going on.
Logic implies I need a + diopter eyepiece. I use the camera with my glasses on so my nearsightedness and astigmatism should be corrected by the glasses. Presbyopia makes it difficult to see things close up even with my glasses, so a + diopter should make the VF seems father away and easier to see.
Experience says I need a - diopter adjustment. Most of the VF diopter adjustments I have (X100, NEX EVF, GH2, etc.) have no calibration marks at all -- I can't tell if I'm dialing in + or -. However the two that give a clue as to direction (Olympus m43 VF-2, and E-5) say I'm dialing in a slight -
Could the Olympus viewfinder marks be reversed? Is my logic reversed? Any insights would be appreciated.
Not sure if this helps, but I'm slightly nearsighted, but have presbyopia as well. I need a -2 diopter, so this suggests that a '-' adjustment what is helpful for presbyopia. How strong is the issue since the viewfinder may not be neutral. For example I believe that my OM2 is a -1 without a diopter, so you may need a bit of trial and error. I'd suggest having gone through this, that to start, underestimate the strength required a bit, your eye's seem to able to handle a bit of undercorrection better than an overcorrection. I started with a -3 and I couldn't see a thing, -1 was a bit weak, but usable.
You can figure out which way is - and which way is + by quickly scrolling from one extreme to the other and feeling how your eye tries to compensate for the shift.
Once you've figured out which way is which on the X100, it might be worth finding someone with normal, perfect eyesight and have them adjust the diopter so that they can clearly read the viewfinder info. Then look through the viewfinder with your glasses on. Can you read the viewfinder information clearly? If not, adjust the diopter until you can, and note which way you turned it. If it feels like your eye is straining because the readout is too close, then your logic indicating a + diopter would seem to be correct.
I suggest the X100 because it would appear that its viewfinder configuration is very similar to the new XP1. However, it's obviously not the same because the XP1 doesn't have built-in diopter adjustment, for whatever reason (I am curious why Fuji couldn't include it).
I just tried my Canon 1DIV. Without glasses on, it's set towards the - side. With my glasses on, the diopter is at about the default 'normal' setting. I'm also somewhat nearsighted, so this would be the logical conclusion, that it's necessary to move the diopter in the + direction to compensate for my - diopter glasses. But I don't seem to have presbyopia issues yet. I can still see clearly with glasses down to about one foot. How close can you focus with your glasses on? Around 3 feet? My guess, based on my SLRs, is that camera viewfinders are optimized for about this distance range.
I haven't used an X100 so I'm not sure what it's like. With the Leica M9 the viewfinder feels like there is a lot of depth, in that the scene I'm viewing doesn't feel like my eye is focusing much differently than when viewed straight on. It feels like I'm viewing 'through' the viewfinder, rather than looking at an image projected onto a focusing screen. When I read the M9's exposure information, I can feel that my eye focuses much closer. With my SLRs, the image I see on the focusing screen feels like it's the same distance as the exposure readout information. My suspicion is that the X100 is complicated because it's a hybrid of the two. In OVF mode, you should be able to view through the viewfinder and see the scene clearly with your glasses, though the exposure info might not be perfectly clear. When you use it in EVF mode, then it will be much like an SLR where you're viewing everything at one set distance. This is where your presbyopia might be an issue and therefore the need for a diopter.
As a side note, I recently had the chance to try a number of Leica's diopters in-store on my M9 and found that I was best served with the -1 strength (I don't wear glasses for photography). The M9 viewfinder is set at -0.5 diopters, so I guess my eyesight is natively around -1.5. Trying the options in-store was helpful because I learned that there were a range of diopters I could have used with acceptable results, meaning at least for me, there wasn't one option that was extraordinarily better than its neighbours (in half diopter increments). For fun I also tried some + diopters and it was immediately obvious that the - direction was what I needed. The + diopters didn't make the viewfinder look farther away, just completely out of focus for my eyesight.
