LF critical focusing ....Loupe, specs and deteriorating eyesight

Asha

Asha

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Asha
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I know the difficulties of manual focusing wearing specs using SLR's etc has been covered in another thread, however my problem relates specifically to critical focusing on the GroundGlass of LF cameras.

Increasingly I am missing focus and tbh I don't know how to overcome the issue.

I possess two loupes, a 3.6x TOYO and a 4x ( i think) Schneider but I'm wondering if a stronger magnification will be better.

Typically i will use the loupe without wearing my specs but either way i still have difficulties..

Having done some reading, some folk find a higher magnification is detrimental as it increases the size of the grain in the GG and as such can render the image soft and difficult to focus on.

The problem is the same with all my cameras regardless of Fresnel screens, lenses and overall brightness of the image on the GG

So how do you guys go on?

Is it worth trying a stronger loupe and if so, which one??
 
Can you adjust the focus on your loupe so the grain on the gg is sharp with out your glasses? That would remove one optic layer.

I've tried a 8x loupe but it's too much I found, stuck with the 4x.
 
steveo_mcg said:
Can you adjust the focus on your loupe so the grain on the gg is sharp with out your glasses? That would remove one optic layer.

I've tried a 8x loupe but it's too much I found, stuck with the 4x.
Click to expand...

Yes it’s possible to adjust the focus, like à diopter on the Schneider which helps in so far as using without specs hence I prefer that loupe to the Toyo .... nonetheless I still struggle.
 
Contact lenses for your eyeballs rather than a might be one practical solution.

I wonder if anyone makes diopter screen additions for common camera finders? That way you can use the standard finder but it's adjusted for your eyesight. Loupes could be more problematic as I assume they're handheld and that's when the error creeps in.

Are the fixed magnifiers in TLRs any easier to use? If so replicating something like that might work.
 
srichards said:
Contact lenses for your eyeballs rather than a might be one practical solution.

I wonder if anyone makes diopter screen additions for common camera finders? That way you can use the standard finder but it's adjusted for your eyesight. Loupes could be more problematic as I assume they're handheld and that's when the error creeps in.

Are the fixed magnifiers in TLRs any easier to use? If so replicating something like that might work.
Click to expand...

Contact lenses maybe a consideration at some point if I can tolerate inserting them but it’s not something I fancy if I’m honest.

It’ll be awhile before I give more thought to that option as it’s less than a year since I obtained my present specs.
 
I had a somewhat similar problem last year with my TLR focusing Asha, and got the optician to give me a number for reading specs, which didn't really solve the problem. I then went back to the optician with the TLR to show exactly what I was trying to focus on and at what distance. This resulted in a really scary pair of specs which are only in focus for slightly more than the measured distance, and can only therefore be worn for focusing and nothing else. It's not a great solution in all honesty, but it does help when focus is critical.

For 4x5 I have the Cambo Reflex viewer as shown at the link, but that's quite difficult to get used to compared to a loupe, although it has the added advantage of not needing a dark cloth. Not much use for your 10x8 though, and it didn't seem to be a good fit with Nick's Chroma when we tried it at Onich.
http://skgrimes.com/whats-new/2006-2/cambo-reflex-viewer-fitted-to-a-ebony-sv45te
 
Peter B said:
This resulted in a really scary pair of specs which are only in focus for slightly more than the measured distance, and can only therefore be worn for focusing and nothing else. It's not a great solution in all honesty, but it does help when focus is critical.
Click to expand...

When your eyesight is going (well the focusing bit) that's what you have to do.
For me my eyesight is quite good but the focusing of my eyes doesn't work any more, so I have spectacles for different distances i.e. close up, reading, watching tv and long distance.
 
I've got reflex finders for my Toyo and Horseman and I prefer them to using a loupe and darkcloth. However I think a loupe is essential if you are using complex movements and need to check focus on the outer edges of a shot. I find myself only using rise and fall and a bit of front tilt and the reflex finder is OK for that. Mind you, it isn't what you would call portable.

As far as spex go, since my cararact operatoins, I find I have to have lots of different strength glasses, 2 dioptre for reading, 1.5 for music and computer, varifocals for driving (so I can read the instruments).
 
Does your LR have a Fresnel screen, a brighter image may make it a little easier to focus. There has been another thread where people are using a cheap reading Fresnel and say it's a massive improvement.

Most loupes have adjustable focus on them, maybe pop out the ground glass holder and put a light source and negative (emulsion side up) behind it and set up your loupe to focus without your glasses, you should not need to adjust it from that unless your eyesight changes. Mark it with a bit of tipex or white marker pen. If you go down the Fresnel route then you will need to set up the loupe focus to be a couple of mm further away to look through the Fresnel. Do the same as above but with your Fresnel in-between, before you fit it to the camera.
 
I normally use contact lenses, although I'll admit to having switched to spectacles again because of the difficulty of reading without reading glasses, and my optician provided a couple of pairs of adapted-for-reading spectacles that makes near and distance easy. With that out of the way: focusing with my Rodenstock 4x loupe is simple with contact lenses. I assumed that, because I'm short sighted and focus on the RZ67 using the magnifier on the WLF with equal ease with or without specs/contact lenses, that the loupe would be the same. It isn't. I need accurate infinity correction with my eye before I can see the ground glass clearly, even with adjustments to the loupe. So it might be worth while making sure that your infinity focus with glasses is spot on.

I actually find being short sighted helps when viewing the ground glass as a whole under the cloth, as I can get close up and still focus on it. My left eye achieves focus at about 7 inches...
 
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