To loupe or not to loupe?

[kev curry]

Can anyone explain what the fuss is with selecting a loupe - what brand, what X magnification or why use one at all? I learned how to focus the view camera after reading
Ken Rockwells site where he explains how to make a little paper dial that goes around the focusing knob of my Tachihara - the dial calculates the distance between the near/far objects in the scene that are to be in focus, then the dial is used to find the midway point between the two objects and hey presto the optimum fstop is selected from the dial for shotting the scene - beautifully simple and can be done easily by eye in 30sec's!
I have never had to use my home made loupe, even when shotting close-ups I find I get sharp pictures - 'things dont seem to be so critical to use a loupe'! I must be missing something here but what?
Thanks
kev

[David A. Goldfarb]

I remember attending an exhibition of an architectural photographer who never used a loupe, and you could tell from the prints. Usually people shoot LF because they want more control over the process, and using a loupe is one way, whether your goal is for everything to be sharp or for most everything to be unsharp. If you use very narrow selective focus, it's even more important to use a loupe so you don't miss the target.

As for the debate about which loupe and how much magnification--well, too much magnification and the fresnel and the glass get in the way of seeing the projected image. Too much distortion and you invite eye fatigue. Some loupes are better in the corners and some are better with wide lenses.

Try focusing without a loupe, and then checking with a loupe, and see if you choose a different focus point with the loupe. If you do, then it will make a difference. If you don't, then maybe it doesn't matter for the kind of subjects you shoot.

[Ted Harris]

I remember attending an exhibition of an architectural photographer who never used a loupe, and you could tell from the prints.

Well said. I look at a lot of negatives and transprencies shot by others; look at them and scan them with a high end scanner. More frequently than I would have imagined 10 years ago whne I look at a highresolution scan I am looking at a not quite focused image or at best not perfectly focused image .... an image that just will not hold up to printing any larger than 8x10 or 11x14 and even then the lack of focus is sometimes noticible. This even applies to some very well known photographers. In fact, I was working with some 35mm slides from a very very well known National Geographic photorapher the other day and was amazed at the number of them that were not critically focused. With regard to LF the whole point is that I am certain taht most if not all of those not-quite-focused images I look at were produced without using a loupe and it really doesn't matter if you have perfect eyesight, are near sighted, etc. ... your focus will improve when you use some sort of magnifyng device.

Since the human eye is the weakesr link in the focusing system why not give it some help?

[Donald Qualls]

I'm nearsighted enough that I can see the ground glass about as well with my naked eye (looking over my glasses) as I can with my glasses and 8x loupe. Part of the problem is that my loupe (a very inexpensive one) isn't designed to compensate for the thickness of the glass, so it doesn't focus perfectly on the ground surface when in contact with the smooth side. The other problem is there's so much distortion from the simple monocle lens that only the very center is in focus even when the image is in focus; it's actually easier to use reversed, with the cup surrounding my eye, but that's really only practical for inspecting negatives, because of the need for a free hand to hold the loupe (it's a little large to capture with my facial muscles as a jeweler would do when examining a diamond).

Some time I hope to get a better loupe -- preferable one that will either clip to my glasses or that I can hold with my brow and cheek -- and a Satin Snow ground glass; the combination should improve my focusing a bit...

[Vaughn]

<snip> it really doesn't matter if you have perfect eyesight, are near sighted, etc. ... your focus will improve when you use some sort of magnifyng device.

Since the human eye is the weakesr link in the focusing system why not give it some help?

Unless you are very near-sighted yourself, you have no idea of how us near-sighted people see close-up w/o our glasses. You are just guessing...you have no idea of what it is like looking at something, in focus and sharp, at 3 to 4 inches from your eyes.

To use a loupe, I am using two seperate optical systems -- my glasses and the loupe...and there is a good chance that the loupe is not designed to give maximum performance with glasses (placement of the loupe relative to the eye is much different, for example). The focus with a loupe w/ glasses could easily be inferior compared to not using it (for near-sighted people w/o glasses).

Vaughn

[Colin Robertson]

When starting off I assumed the 'loupe cult' to be BS. Then I noticed that at 20x16 some prints weren't criticaly sharp. So, I bought a cheap loupe to test . . .
First I would focus naked eye, til I was SURE I had nailed focus. Then I'd loupe it. 50% of the time I had to make some minor tweak. Shocking. So now I carry a Silvestri 6X (I think) loupe. It is fabulously clear and sharp. If I shoot chrome, it costs £2.20 a sheet, plus £2.50 to process- that's a total of £4.70 (or nearly 10 US dollars) every time I click the shutter. Why risk that shot to save 30 seconds??
OKay- 90mm lens, f22, you'll have lots of dof, and it'll probably save your ass. But 360mm lens, f5.5, at 10 feet? There's NO dof. Why guess focus? Use a loupe.

PS No. I'm not a loupe salesman

[RDKirk]

Unless you are very near-sighted yourself, you have no idea of how us near-sighted people see close-up w/o our glasses. You are just guessing...you have no idea of what it is like looking at something, in focus and sharp, at 3 to 4 inches from your eyes.

LOLBWYNAY

A loupe does the same thing for a normal eye's lens that a "close-up filter" does for a normal camera lens. But the myopic eye is like a normal lens with an extension tube, so what he sees through a loupe is exactly what we hyper-myopic folk see "normally."

If a person with normal vision can focus as close as 10 inches, a 2x loupe gets him optically as close as 5 inches. What he sees is exactly the same as a myopic person who can see without glasses down to 5 inches.

Personally, my own hypermyopia gets me down to 3 inches. But to use a loupe, I have to use my glases--in fact, the lower portion of my bifocals--to first correct my vision to "normal" then the loupe allows me to focus to the same magnification that I could have seen without any external lenses at all.

Optical principles are optical principles.

[kev curry]

Colin Im glad your weathers good! Im sitting waiting to see if theres going to be a little weather window tonight for a shot Im trying to get of Lock Arklet with Ben Ime and Ben Vorlich as the back drop! I went the other night just before dusk and the light was extraordinary! I managed to set up and compose two shots, inspite of being eaten alive by 'the midges' but something wasnt right the shutter speed was to high, something was nagging me all the way home, but I new I had metered correctly! As I later discovered, during the horror of being eaten I some how managed to set the ISO of the meter to 3200 instead of 320......think that places the shadows on zone0! Bummer.
Once I get a van on the road and make my much awaited trip to Skye for an extended break I can easily take a Calmac -criminally expensive ferry- from Uig and discover your beautiful Island with rock shoes and a 5x4!

cheers
kev

[kev curry]

The point made in the last sentence is very good. It's a point that's made over and over again by John Sexton in his workshops. If you don't have the basics right (such as focus in the case of this thread) then don't worry about the minutiae of cameras, lenses, tripods, etc. that are discussed so often in this forum, they're totally irrelevant to you.

I really do take this on board!
Ps: I really admire the work of John Sexton!
Cheers
kev

[Nick_3536]

The smaller the format the more I find I need something. Loupe,line tester something. With 8x10 it's less of an issue for me. But that's my eye sight at the moment.

I tend to do most of the focussing without then I fine focus with.

How much added weight/hassle is using one? It's not like you are hauling an ultra light setup to begin with. It's also not like you're rapid firing the camera either.