focusing loupes

[Bob Haight]

I have been reading earlier answers on this topic. My question is are loupes suc h as a 6x for slide review good to use to focus on the groundglass or are loupes specially designed for focus better to use. Also, is a longer loupe helpful suc h as the one Toyo makes.

[John Burke]

Bob -

I've actually found that my ground glass viewing requirements are somewhat less stringent than my slide viewing ones. That is, a pretty basic loupe serves me we ll in the field for my 8x10's g.g., although I do like nicer optics for viewing on the lightbox. I think I paid $10 for a super-basic 8x loupe that I use on the view camera, and it's plenty for the job. Obviously, your mileage may vary, and maybe my laxity is a contributing factor to my not being a professional photogr apher, so...

[Brian Ellis]

When you use a loupe on a ground glass, you're using it solely to magnify the image. You aren't checking color balance or hue or anything else that you might be checking when viewing slides on a light table. Since you're using it only as a magnifying glass, you don't need any particularly great optics. In fact many people use magnifying glasses sold at drug stores instead of loupes, others use old 50 mm camera lenses, I think that almost anything that will magnify the image without creating weird effects will do.

[Eugene]

Bob, when you use a high power loupe, the grain in the groundglass and/or the rings in a Fresnel screen are magnified to the point that they become distracting. A 4X loupe is strong enough to use for focusing on a groundglass, and still function correctly. The Toyo long loupe is designed to be used with the folding focusing hood on the Toyo field cameras. It's long design enables reaching into the hood. It has rubber protective rings at both ends to prevent scratching the groundglass and/or eyeglasses. it is just under 4X power and does not allow for diopter adjustment. The Wista loupe has diopter focusing capability. It's smaller than the Toyo and in the same price range, but it does not have the rubber protectors.

[Noshir Patel]

I would add that there is one big requirement for a focusing loupe: A neck cord. I like the silvestri tilting loupe, but I rarely use the tilt feature (meant to view corners and edges for wide angle lenses), so I'm not sure it was worth the money.

[neil poulsen]

I used a makeshift loupe based on a magnifier. It seemed OK until I purchased a Calumet 4x loupe. The Calumet (I think originally made by Rodenstock) works great for gg focusing. It's like the image just jumps out at you when it's being used for the gg. The Calumet also works well for 35mm slides, but it's a little too small for 2 1/4.

I wouldn't be without one.

[Julio Fernandez]

Bob: I have tried several loupes on my Technika 4X5 and my observations are: 1) On a groundglass of good quality a 10X loupe does not overemphasize the texture of the glass to the point when it becomes obtrusive. If the glass were coarse I can see it would become obtrusive. If your 4X5 screen is too coarse for a 10X loupe I would replace it for a finer one. 2) I found that with a good 6X loupe, (Horseman) images which in the GG appeared sharp were not on film. Moving to a 10X I found that the slightest amount of focusing movement could be clearly detected allowing very fine focusing and yielding sharp images on film. 3) In careful inspection of images on the light box, the better loupe, in this case one made for or by Leitz showed better contrast and sharper images. 4)Much better than drugstore lenses are prescription lenses formulated by your optician for optimum magnification for the size of the screen you will be viewing. With sugh prescription glasses you can view the screen at the maximum magnification which still allows you to view the entire screen. This is helpful for studying the composiion on the GG. Also, the results are fantastic in as much the visual accuity is excellent, however, that magnification (3.5X) was too low for me to rely on these glasses alone; If I do not use the loupe for fine focusing, the images on film were unsharp. 5) Things are different on 8X10 because on 8X10 the image on the GG is already magnified 2X that on 4X5 using standard lenses in both cases. Thus, the magnification required of the loupe is inversely proportional to the camera format. Accordingly, on 8X10, a 6X loupe should be adequate and even a 4X loupe may be OK. On 4X5 I am using a Silvestry 10X which I find extremely sharp and long enough to keep my nose away from the GG. The Horseman 6X is the longest loupe I know. Their 7X is about the length of the silvestry. It is a good loupe but I prefer the 10X Silvestry. Loupe lengh is important in cold humid weather to prevent fogging of the GG. 6) Good loupes have flat fields throughout the whole image so that squares stay square to the edge of the field; also, their fields are wider. One problem with some loupes is that their field is so small that you lose yourself in the GG. 7) Mamiya also makes very good loupes of various magnifications. 8) Modern loupes being made by Schneider, Rodenstock, Silvestry and Mamiya have flat and usually wider fields, and those for GG viewing are longer than the old fashioned loupes which some manufacturers still make. I remember an old Linhof 8X loupe which was only about 15mm long. For GG viewing it posed a strategic problem: what to do with the nose, bend or amputate. Good viewing!

[John Kasaian]

Bob, FWIW, I started with an ordinary Agfa 8x loupe, the kind just about every camera shop has on hand. I think it cost $6 when I bought it. It works! I plan on getting a Silvestri tilting loupe as soon as B+H gets them in stock because when you have to position your camera in a awkward angle, focusing can get to be a pain in the neck-- -literally. The Silvestri also has a cord and while I have never misplaced my Agfa in the field, I like the security of a neck cord and If I can hang the thing around my neck I figure I'll have one less thing to put in my pockets(I guess its also a status symbol of sorts, like having black fingernails from amidol.) Also, B+H prices are only a few bucks more than the Toyo, so why not go with the tilting feature? If the Italians can produce a loupe even remotely similar to Sophia Loren, I'M THERE!

[Bob Salomon]

:I remember an old Linhof 8X loupe which was only about 15mm long>

Still avaiable.

[Steve Gangi]

I tried a cheap 8X slide loupe for a while and didn't like it. There was too much magnification and too much image distortion. Now I use a Toyo 4X magnifier and am much more satisfied. It gives a nice sharp image, and is large enough so I won't lose it.