SRT 101 and old eyes

[royall_berndt]

I just shot a roll in my "new" 101, and all but two shots were badly focused. As some of you know, the 101 does

not have split-screen focusing, which I tend to rely on with MF cameras. But even a roll shot recently in a

camera with ss focus had a lot of fuzzy shots. If I don't want to be confined to auto-focus, I apparently need

diopters. My near vision has weakened recently. Do I need a diopter with a negative number or a positive?

[JDMvW]

<p>You might get a handle on what and how strong you need by taking the camera to a place that sells inexpensive reading glasses for us old folks (here, drug stores and such) and trying focusing with different strength glasses on.<br>

If you have reading glasses already, try wearing them when you are focusing and see if that helps, but I would presume the power of the lens would be similar to those glasses.<br>

If cataracts are the problem, you need to see your eye doctor.</p>

<p>They went ahead and fixed my vision when I had other eye surgery done, so now don't have to wear glasses at all. ;)</p>

[Mike Gammill]

I wear bifocals and focus best with the part of lens corrected for distance.

[john_shriver]

<p>Welcome to presbyopia!<br>

You want the right diopter to make things sharp at 1 meter distance, that's the "virtual distance" of the focusing screen in an SLR. So go to a drug store, and see what reading glasses give you the sharpest view at 1 meter. That's the diopter you want. You can just use reading glasses of that strength, or you can have an optician make you a lens of that diopter that will fit in the eyepiece.</p>

[Matthew Currie]

<p>Diopters for old Minoltas seem to be a bit scarce in the used market at least, but as far as I know all Minoltas through the Maxxums used the same rectangular diopters that snap into the finder. </p>

<p>However, you will notice that the finder also has slots in the side for slide-on accessories, and I found that the same size was used by Yashica and Contax, so another possibility might be a slide-on magnifier or diopter for one of those. I don't know what might have been available in eyepiece diopters, but I have a Yashica magnifier attachment that pops right onto my SRT-201 or my X700. </p>

<p>In addition, although Minolta and Yashica slide-ons will not fit the slightly larger Nikon rectangular eyepieces, Nikon accessories will fit on the Minolta without a problem. I just tried the DK-21M magnifying eyepiece and the DK22 threaded adapter that I have for my Digital Nikon, and they fit the SRT-201 quite nicely. The DK22 is pretty cheap, and onto that you can put any of the round diopters made to fit older (pre-HP) Nikons, such as the F, F2, F3 other than HP, and Nikkormat, which may be easier to find than a Minolta diopter. The DK21M is 1.17 power magnifying eyepiece that reduces eyepoint somewhat, but also has a slight positive diopter. </p>

[jcofer1]

<p>I believe the slide-on diopter lenses for the Nikon FG/FG-20/EM will also fit; they fit perfectly on the X570/X700 series, as well as the XD-11.</p>

[mukul_dube]

<p>A possible complication is that the strength ("power") of reading glasses that are right for you with your camera may not be the marked strength of the diopter you need. A decade back, while trying diopters on my Canon SLRs, I found that the one marked "+2" showed up as +3 when measured by my optician. This is to compensate for the negative diopter built into camera finders.</p>

[john_shriver]

<p>Yes, some (but not all) camera vendors mark their diopter lenses with one less than their true strength, as they mark them with the "effective" diopter combined with the -1 diopter of the finder system. (That the focusing screen is at a virtual distance of 1 meter makes the optics of the finder be -1 diopter. If the optics were 0 diopter, the focusing screen would be at a virtual distance of infinity.) If Minolta did this, there would be no "-1" diopter lens available.<br>

Realize also that the camera might be out of adjustment, and isn't focusing correctly. Have someone who doesn't need reading glasses test it for you, or use reading glasses yourself.</p>

[lex_jenkins]

<p>My sympathies. I just replaced the focus screen in my Nikon F3HP, returning the original K screen to duty. I preferred the E grid screen but could no longer see well enough to use it properly, and the eyepiece on my DE-3 finder is buggered so I can't install a diopter.</p>

[Alex_Es]

<p>I've found that shooting with cheap reading glasses helps if you cannot find a diopter. You might try a right angle finder or a magnifier. There are a number that can fit Minolta. Try Canon, Asahi, Olympus if you cannot find Minolta. These may require tweaking. If all else fails, cheap drug store reading glasses are the way to go. You might take your Minolta to a drug store and experiment with reading glasses and find out what strength you need.</p>

[mukul_dube]

<p>I had a special pair of glasses for my film SLRs. Right lens correct prescription for clear view through finder at 1 metre. Then my vision began to change rapidly due to cataracts and I had the lens replaced roughly every two months. My optician is not expensive.</p>

[Matthew Currie]

<p>I don't know about other right angle finders, but although the Nikon version does include considerably diopter correction, it also makes the image in the finder very small. Not very practical. The magnifier works very well, but beyond a fairly small increment you will not be able to see the whole screen at once. Nikon's flip-up magnifier, which can easily be adapted to this system using the DK-22 adapter, will make critical focus quite a bit easier, but you'll have to flip it out of the way to compose.</p>