Correct focus?

[polypal]

Many of us use reading glasses to correct our aging eyesight.

Some of us also use glasses with our Hasselblad camera.

To my surprise the diopter value for reading is not the correct one when using a prism or the magnifier in the WLF.

My reading glasses have a + diopter correction while I use -1 diopter with my camera.
The different diopter value is caused by the smaller distance from the eyepiece to the focusing screen.
I found the correct value using a calibrated chimney finder.

Hasselblad finder with adjustable diopter.



The only correct use of glasses is with the focusing screen at reading distance, of course without the use of the magnifier.

Owners of the PME45 and the PME90 are lucky, they can adjust the eyepiece for correct focus.

Hasselblad offers a range of correction lenses for older prisms.
The situation for WLF is not so good, only one diopter value still available for that finder.

Contact the moderator if you have trouble finding a correct diopter lens.

 

[gradasso]

Focusing

"Owners of the PME45 and the PME90 are lucky, they can adjust the eyepiece for correct focus."

Right, Polypal, but the same possibility is offered from the old 90° p.prism HC4 (52086) that I use habitually.
The optical system of this finder is awful (on its frame I read the mark "Hensoldt Wetzlar" - nothing to do with Leitz,I fear), but I often prefer to work with camera handhold at eye level, an habit from using 35 mm.
I agree totally with you about glasses and their use and limits. But if we were more young we perhaps should go around shooting with our cellular telephone!
Cordially Ale

 

[wbulte]

"
The optical system of this finder is awful (on its frame I read the mark "Hensoldt Wetzlar" - nothing to do with Leitz,I fear), but I often prefer to work with camera handhold at eye level, an habit from using 35 mm.
I agree totally with you about glasses and their use and limits. But if we were more young we perhaps should go around shooting with our cellular telephone!
Cordially Ale

Hensoldt is not a shabby firm by any means, as quite a lot of game has found to their disadvantage (Hensoldt built rifle scopes, maybe they still do, dunno).

As for camera phones: iPhone is on its way to be the most-used 'camera' on a number of photosites (Flickr etc).

Ah well, whatever makes them tick, I see my iPhone as a last-resort camera myself..

Wilko

 

[terrydent]

Any reading glasses I might use are +2, +2.25. A Hasselblad diopter that is correct for me is -2 or -3. Aren't all reading glasses +?

I think the last series of prism finder eyepiece go from +2 to -2 which is a big help. I do have a clip on diopter that increases the range to -4.5 for those prisms.

Terry

 

[polypal]

Hello Terry,

In your case the difference between reading glasses and the correct diopter for Hasselblad is even larger than with me.

A correct diopter is a great help to focus.
For some strange reason the human eye seems able to adapt incorrect diopter values.
This requires a lot of effort and is not recommended.

The diopter range for the PME 45 and the PME 90 can be extended by fitting a suitable lens.
The range can be extended both for larger positive or negative values.


Paul

 

[pierre506]

It's a good tool to help focus~