Focusing Using a Loupe

[Harold_4074]

I would guess that the subtlety arises from the eye's ability to compensate for objects at different distances.

Precisely.

Even at somewhat advanced age (like mine...) the eye still has some accommodation ability. The trick is to learn how to focus the loupe with your eyes at "infinity focus", that is, totally relaxed. If you can do this, you will be able to "feel" when the camera is focused, because the image will be sharp and the eye relaxed. It is, however, easy to mess this up in the heat of the moment.

The next best thing is to learn to focus the camera while moving your head very slightly from side to side; the camera image will move in relation to the image of the groundglass unless the two are in the same plane so that the parallax disappears.

I have three or four loupes of different ilk, but find the best of them all is a no-name 35mm camera lens, used backwards---I think it is a 35mm, but a 28 would probably be even better. There is no skirt, of course, which forces me to get the groundglass sharp first, before bringing the aerial image into its plane.

[rdenney]

why is this so complicated
shorter skirt or longer skirt
whatever
done

it seems too much words too much gear to much review not enough doing

its just a magnifying lens
focus

Well, Mr. Sun, nobody can accuse you of using too many words, heh.

Rick "who finds two few words usually more confusing than too many" Denney

[rdenney]

I never realized focusing with a loupe was this complicated. For over 15 years I've put the loupe against the viewing screen, put my eye to the loupe, and adjusted focus until the appropriate point(s) (usually near and far) of the subject appeared sharpest. Always seemed pretty simple.

It did to me, too, when I'd been doing it for 15 years. Assuming that provides an estimate of your age, I would submit that in another 15 years, it might not seem so easy. The first thing I had to do when I moved back into large format recently was upgrade my loupes. The shift to trifocals and the general loss of the ability to focus my eyes over a wide range suddenly brought the problems with that process into, um, sharp focus.

Rick "who has, on occasion, also successfully used a cheap 35mm lens as a loupe" Denney

[Jack Dahlgren]

Rick "who has, on occasion, also successfully used a cheap 35mm lens as a loupe" Denney

Cheap enlarging lenses work too and may be less bulky.

[cowanw]

Rick "who finds two few words usually more confusing than too many" Denney

Actually when there are only two fewer words, I can pretty much fill in the blanks. But, in truth, the tendancy of many (often politicians for example) to use far to many words to say too little is confusing, As it is meant to be.

to obfuscate
too often
is two more
to,too,two's
Regards
Bill

[rdenney]

Actually when there are only two fewer words, I can pretty much fill in the blanks. But, in truth, the tendancy of many (often politicians for example) to use far to many words to say too little is confusing, As it is meant to be.

Then there was the guy who wrote the mathematical statistics book I had in grad school. I had to read every paragraph 15 times to get any sense of what the author was saying. It seemed to be written to people who knew as much as the author, which makes one wonder why he bothered to write a textbook in the first place. The reason it was so dense seemed to be that the author wrote to impress himself, rather than to illuminate.

Skilled writers can obfuscate with brevity if that is their intention. That's why the language includes both "brief" and "succinct". Succinct clarity is a rare talent not often possessed by those who attempt it. Politicians who use verbosity to obfuscate are showing incompetence in addition to deceit, but so are some who confuse simplicity with being simplistic.

Rick "whose many words are offered in good faith" Denney

[Bob Kerner]

Wow. This has thread taken a life of its own!
Glad I didn't ask about Scheimpflug

Thanks again for everyone's help.

[sun of sand]

Succinct clarity is a rare talent

evidently not
read the internet and you see the word printed almost as often as
lol

[archer]

My grandfather was a politician and when I became the COB of the Professional Archers Association and had to address the national meeting I remembered the quote he used to help me with my first address. "be concise, be succinct, be honest and be seated!"
Denise Libby