Loupe Mag Power X for 4X5?

[JWMster]

Newby looking to get into LF 4X5, I'm trying to understand the LOUPE. I've had a plastic thing and YIPES! it's not what I'd like to use or depend on for more than looking at negatives. Real optical glass seems the way to go, and likely (from a survey of ebay and elsewhere ) means spending somewhere north of $50.

So here's my question - and some of what I've seen in old LOUPE threads may be differentiated between who is using 4X5 and who is using 8X10 - what's the "right" MAGNIFICATION X for 4X5 ? Let me add that I'm seeing a lot of good mfg. names have put out loupes with 3X and 4X, and up to 8X, but I've also seen "ZOOM" Loupes that do 8X up to 16X.

Suggestions welcome. Thanks!

 

[jim10219]

It's totally up to you. Some of it depends on your ground glass. Too much magnification and all you see is the bumps on the glass. Too little, and it doesn't really help with focusing. I think most people go with something around 8-10x. I use an 8x cheapo thread counter and prefer it to traditional loupes, which can cost 10x-30x more.

 

[craigclu]

I happened to own a 4X Rodenstock for darkroom duties when I got more seriously into 4X5. Perhaps I don't know the difference but it has worked perfectly for me and I find the magnification sufficient for the duty. Whatever you decide on, do a little research on proper focus. Take the lens off and be certain that you're focused on the grain side of the ground glass so that you're at that focus point when the image is projected to where the film plane will be.

 

[JPD]

I use a single element "watchmaker's" loupe and it works just fine. I'm only using the center of the lens when I check the groundglass, so aberrations in the corners don't matter for me. That said, I will probably buy a little better loupe soon.

Voigtländer had an interesting loupe in the 1920's-30's. The "Scharf-Richter", which not only aided in focusing but also had prisms inside that turned the image 180º. "Scharf-Richter" is a very clever play on words.

 

[shutterfinger]

I use a Horizon GHZ103 focusable loupe https://www.ebay.com/itm/NICE-UNUSE...462050?hash=item2ce836bb62:g:lCoAAOSw5ydci-Y7 probably not available new anymore. They were about $45 new in the late 1990's.

A thread counting loupe: https://www.ebay.com/itm/10X-30mm-F...xMAAOxyzi9SgkzO:sc:USPSFirstClass!94080!US!-1

 

[StepheKoontz]

I use a rodenstock aspherical 4X for viewing negatives and a Toyo 3.6X "long" magnifier for the ground glass like the one pictured below. The toyo would probably work OK for both.

 

[Jerevan]

Late answer, but might be of interest as a future reference if anyone is looking for other options: I started out with a 50 mm lens (which reportedly is about 5x magnification, no matter - it worked out fine). It is possible to focus it on the grain side and put a piece of tape on it to keep it where it should be.

 

[Deleted member 88956]

1+ for Toyo ground glass loupe, just about right x ratio and length helps too. There are other more expensive options from Silvestri and the likes, but all one should care about is magnification to be in a sweet spot, not glass quality, distortion correction etc. so no need for anything exotic.

 

[Maris]

A plausible theory is to use a loupe with a power higher than the planned enlargement ratio. Making a 8x10 enlargement? Then a 4x loupe is more than enough. Making a 16x20? Then a 6x loupe is better. The basic idea is to focus finer than the detail you will need.

 

[DREW WILEY]

I like the Peak 7X. It's been sold under Horseman and Nikon labels too.

 

[Deleted member 88956]

A plausible theory is to use a loupe with a power higher than the planned enlargement ratio. Making a 8x10 enlargement? Then a 4x loupe is more than enough. Making a 16x20? Then a 6x loupe is better. The basic idea is to focus finer than the detail you will need.

Focusing on ground glass has no connection to final print size.

 

[MattKing]

Focusing on ground glass has no connection to final print size.

No, but observing the resolved detail does - particularly when considerations of corner detail and depth of field come in to play.

 

[ic-racer]

I use the same 8x loupe to examine all my negatives from 8x10 to Minox.

 

[Deleted member 88956]

No, but observing the resolved detail does - particularly when considerations of corner detail and depth of field come in to play.

My point was that (possibly a personal preference) focusing on ground is not the more loupe power the better. What one considers just right for ground glass focusing it will cover all issues. I don't need high power to look into DoF, while using rather low to focus the image. That's why I see no relation. How is my final print size affect how I focus on ground glass? If we're trying to say that this print size is good for sloppy focusing and another needs more critical focusing ... that's a bit off a wall. Focus how you like it so negative fits the image to be, print small, big, whichever. Once we try fitting our focusing routine to final print size, we are diluting the principles of getting on negative what we feel we are after.

 

[Deleted member 88956]

I may have misread OP question: is it for negatives or focusing on ground glass? two entirely different scenarios and I was replying with ground glass focusing in mind.

 

[Ariston]

I bought the cheapest I could find and I don't know how it could be any better. Maybe it would be more scratch resistant or something, but I don't pay crazy money for things like that when I can simply be mindful of my stuff (yes, I'm dreadfully poor!). I do have to be sure to look through the center of the lens, but that is not difficult, and all loupes may be like that... I don't know.

 

[DREW WILEY]

A lot depends on the specific coarseness of grind and whether or not a fresnel is involved. Not all ground glass is the same, and I happen to hate fresnels because they make it difficult to focus on fine detail. But if you do use them, a somewhat lower magnification loupe might be more realistic (like 4X).