TIP: Ground glass loupe for 4 x 5 field camera

[amisoll]

I needed a loupe that had a 4 inch extension for my camera. I didn't want to spend $ 45.00 US (plus tax and shipping) so neccessity is the mother of invention. I discovered that I could use a Nikon 35 MM loupe with minimal renovation. I added for 0.78 cents a 4 inch PVC pipe connector to the eyepiece of the loupe and VOILA it works perfectly. If anyone is interested I will send them a close-up photo of my wonderful invention. I also discovered that if I use Static-Free spray on my negative holders and then wipe them clean and use compressed air , my negatives are 99.9% dust free.
Solli

[Mark Straughen]

I made my home-made loupe from the viewfinder of an old video camera

[John Bartley]

Ummmm ... same here. I made mine from an old slide projector lens that I shortened and adjusted for the correct focal length.

As a related subject, another thread was just commenting on the thickness of ground glass as needed for a Calumet 4x5. When I got my first loupe (a commercially made one), I found that my photos were just slightly out of focus. I did some experimenting on a desktop covered with a glass the same thickness as my ground glass and found that the loupe wasn't focussed unless I lifted it approximately 1/2mm off the glass. I adjusted my homemade loupe on the desktop and it's bang-on when used on the camera.

Soooo ... wouldn't that indicate that the thickness of the ground glass relative to to focal length of the loupe is as important as anything else when focussing?

cheers eh?

John, who really shouldn't think out loud while typing ...

[matthew blais]

I think I mentioned this before somewhere, but I "forgot" my loupe once and in a pinch, the front lens from your Pentax analog spotmeter will work. Not long, but better than nothing.

[Alan Davenport]

Soooo ... wouldn't that indicate that the thickness of the ground glass relative to to focal length of the loupe is as important as anything else when focussing?

I'm not sure that's the case. Since we're using the loupe to focus on an actual image (the one on the groundglass) rather than a virtual image, it shouldn't make any difference whether the loupe is perfectly focused or not. The image will appear best in the loupe when it is perfectly focused on the groundglass. If you use a clear screen and focus on the virtual image, then any focus error in the loupe will translate to the photo, but not so for a frosted focusing screen. Anyway that's how I see it.

Not that any of this makes a blurry loupe desirable...

[BradS]

I rarely find a need for a loupe, preferring a pair of +3 reading glasses. However, I have used a Minolta MD Rokkor-X 45mm f/2 lens. Also makes a nice loupe for viewing negs.