Can't focus my 85 1.8 accurately

[doug_nelson1]

It seems I can't focus any tele. I notice that my vision doesn't seem

to be up to snuff at any of the three levels of my trifocals. I need

to address this, obviously, but I don't want to deal with trifocal

specs when doing photography.

 

I'd like to have my optometrist make me a prescription I can use only

for photography. Should I shoot for 20/20 at infinity, or is there

some distance that is optimum for focusing?

[awahlster]

Doug a better option would be to get a dedicated diopter that attaches to your viewfinder then you would just tip your glasses up and use the camera alone.

 

Do a search on ebay for Canon Diopters I don't know which bodies you are using but the F-1's use a Diopter R the A series and T series will use a Diopter S they do come in different strenghts but you might just buy anyone and have a custom lens made for it might work out the best for you.

[michael_linn]

Of course you could just get an AL-1 which gives you focus confirmation by LED in the viewfinder. I know they are cheap becuse I just sold my nice working example on ebay (no reserve) with a 28mm and 135mm lens for less than $45. I won't do that again but somebody will.

[lance_dennis]

Is this on only one camera?

 

A symptom of a loose lens mount or mis-set mirror stop is the inability to focus lenses. The mildest case would be teles. It would have to be worse if the problem extended to wides also.

 

Have your camera repair guy check the lens mount and the mirror stop first.

 

-Lance

[jtk]

The truth is that SLRs are inherently inaccurate. Think about the angles involved in a split-image SLR screen Vs a rangefinder.

 

As we get older, the smartest among us start shooting autofocus or rangefinders. As you know, rangefinder accuracy is far better than SLR prism accuracy...cannot be otherwise.

 

To get real accuracy from an SLR you need to take your time and prefocus whenever possible. Not necessary with Leica/Canon/CV rangefinder