Best loup for ground glass focusing?

[Ralph Upchurch]

What is the best type of loup to use for focusing on ground glass? Opaque base? Clear base? What power is best?

Thanks,

Ralph

[Louie Powell]

Ralph -

get the plaid one.

Seriously, different people make different choices, and the right answer for you is what works best for you.

I've heard it said that a 4x loupe is ideal - I use a 10x. Some people use an old camera lens (reversed) - a lens from an old super-8 movie camera is supposed to work well. Other people use drug store reading glasses. An opaque base might seem to make the most sense since you are viewing a subject by transmitted light, but if you are using a dark cloth, you won't have any light coming in from the sides that would make a clear base problematical.

[Walter Calahan]

Ralph

As Louie says, get the plaid one.

Eveyone is different. What works for me, you might not like.

If you have a good camera shop near by, I recommend asking them if you can set up your system in their store so to try out a number of loupes. Boston should have one or two good camera stores with a wide selection.

Personally I find opaque best 'cause I usually don't get a very tight seal between my 8x10 camera and the darkcloth. I use a higher power loupe for my 4x5 (10x) than my 8x10 (4x).

Your results may very.

Good luck and happy shooting.

[naturephoto1]

Hi Ralph,

I have used a number of loupes over many years. For a long time I have used the Wista 7X Hood Lupe and it is probably now going to be replaced by my 4X Horizon Lupe with the black skirt in most instances.

I ran a non scientific test of a series of loupes: 3 4X, 1 5X, 1 3X, 1 7X, and 1 8X loupe that I have in a thread at APUG. You may wish to read through the following thread:

http://www.apug.org/forums/showthread.php?t=28786&highlight=focusing+lupe

Rich

[Frank Petronio]

I like the Wista 9x hood loupe these days, it is 5 inches long so your nose isn't greasing up the ground glass.

But a 4X is plenty strong enough for most work. I like the stronger mags for people because I can see their eyelashes. The opaque sleeves are best.

[Bob Salomon]

Wista makes a loupe that attaches directly to the Wista back. The loupe portion comes with both clear (for viewing prints) and opaque (for viewing groundgalles and slides on light boxes. The loupe is supported by wires that allow the loupe to move anywhere over the 4x5 ground glass and stay there without having to hold it in your hand all the time. Once it is moved to the position that you need it both hands are free. It is 5x magnification and has an adjustable eyepiece. It will go up in price at the end of Jaanuary.

[Bob Salomon]

I like the Wista 9x hood loupe these days, it is 5 inches long so your nose isn't greasing up the ground glass.

But a 4X is plenty strong enough for most work. I like the stronger mags for people because I can see their eyelashes. The opaque sleeves are best.

Frank. You mean 7x. Wista does not make a 9x.

[photographs42]

A couple of things not mentioned here.
1. The type of ground glass and whether or not you use a fresnel lens affects your ability to use stronger loupes. At some point you see the grain in the GG or the lines in the Fresnel rather than the detail in the image.
2. Another consideration is whether you need diopter adjustment or not.

Jerome

[Brian Ellis]

I greatly prefer the loupes with a square rather than a round base. The square base is much easier to use along the edges and in the corners (if they're not cut out) than the round loupes and it's the corners and edges that you'll often want to examine most closely. There aren't too many square-based loupes made, I've collected three over the years, all of which are Peak loupes. One is 8x and the other two are 4x. I prefer the 4x. I also own a Toyo loupe which stays home because it has a round base but otherwise it's an excellent loupe. I think it's something like 6x but I'm not sure, it's been a long time since I've used it.

[David A. Goldfarb]

You probably want an opaque base. The opaque base is for groundglass viewing and for transparencies on a light table. A clear or translucent base is for prints and contact sheets.

If you have a fresnel screen, usually something around 4x is best. If you have a plain screen with a fine surface you might want something more powerful. The modern Schneider and Rodenstock aspheric loupes have very low barrel/pincushion distortion, making them comfortable to use for long periods of time.

If you are using a folding viewing hood, you'll probably want a longer loupe like the Toyo 3.6x or the longer Wista or Horseman loupes. With a darkcloth, the length isn't so important.

Silvestri makes a tilting loupe for getting into the corners of the groundglass with a wide lens.

Another important thing when focusing is to be sure to spend enough time under the darkcloth in low light conditions or when using a slower lens to allow your eyes to adjust to the brightness of the groundglass.

[Matus Kalisky]

Well, what I can comment - I have a PEAK 8x loupe with rectangular base which sels new for around $30 and would NOT recomend it because of 2 reasons:

1) You have to look exactly along the optical axis to get a sharp focus (this may have something to do with rather high enlargement factor and small height) - otherwise you will get distorted image

2) The loupe is sharp only in the center - so the rectagular design which I thought will be usefull to focus the corners is useless.

But is light - only 1.9 oz. (54 g) and small.

I would now go for a longer loupe - either rodenstock/schneider/fuji 4x or a loupe designed for the ground glass usage like toyo 3.6x or horseman 6x (~ $150 !), wista 5x, Silvestri tilting loupe 6x

I have tested the rodenstock 4x (at local lab on the light table) and it is beautifully sharp all over.

I also find 8x enlargement a bit too much on the ground glass of my Tachihara - I do see the grain of the fresnel.

I would like to hear also some comments on Toyo , Horsemann, Wista, Silvestri... Toyo is rather chaep - fixed focus (my eyes ares still OK) - but the comments are sometimes positive, sometimes negative. The horsemann is costly, but the users seem to like it... What about Wista or SIlvestri?

Matus

[Dave Parker]

I use a 10x fingerprint loupe that I purchased for about $2 at a sale, it is a highly corrected lens that is flatfield for finger print exam by police. It works very good, I found it at a liquidation sale for a police dept that hand changed everything over to digital, it is as good as any of the expensive loupes that are sold for focusing and slide review.

Dave Parker
Satin Snow Ground Glass

[Alan Davenport]

When I got my first LF camera, I focused using a 5X-10X eyeglass loupe; i.e., one that clipped onto the frame of my eyeglasses. I got excellent focus, but what a nuisance trying to keep the loupe focused on the groundglass image.

Now, I use a 4X loupe that I bought on the bay. I still get excellent focus.

The thing to realize here, is that a better loupe will not help you achieve better focus. When you magnify the groundglass image through a loupe, you also magnify the circle of confusion; this is what allows you to discern the point of correct focus. A cheaper loupe may not render the magnified GG as sharply, but it will still let you see the best focus. A higher quality loupe might be more enjoyable to look through, but it won't help you focus any better.

As for loupe magnification, most people seem to prefer something from 4X to 6X. More than that, and you start seeing more of the grain in the groundglass and/or fresnel lines. Note that seeing these artifacts won't affect the ability to focus, but they tend to make what you're seeing more confusing, sort of a point of diminishing returns.

Get the plaid one.

[Gordon Moat]

With all the comments about plaid loupes, it almost surprises me there are no loupe sleeves on the market. My TOYO 3.6x is a simple enough tube shape that it could easily take a fashionable sleeve. Unfortunately, I don't like plaid (nor suede) . . . guess I will have to stick with black.
:D :cool:

Ciao!

Gordon Moat
A G Studio (http://www.allgstudio.com)

[Arne Croell]

I was trained as a mineralogist, so I use one of my folding triplet loupes preferred in the field by geologists, similar to the ones shown here: http://www.amateurgeologist.com/shop/equipment_loupes.html
I use an 8x one (an older Zeiss Jena), a 10x (Eschenbach) works too, at least with my Bosscreen ground glass. I have tried loupes with a base like the Schneider and Emo ones, but always come back to the one I carry around in my pocket anyway. Since I don't put it on the ground glass there is also no danger I'll change the ground glass position, and it is also much easier to tilt when checking the corners. A matter of personal preference.....

[Lazybones]

I would like to hear also some comments on...Horseman

I use the Horseman 6x loupe; my camera in a Toyo 45AII with focusing hood. This combo lets me focus without a dark-cloth most of the time. The eye-cup design helps a lot. It feels very solid in construction. I agree that it's not cheap, but it does work well for me... But yes, I do find myself wanting to see into the corners a bit more!

My other loupe is a Schneider 6X Aspheric. In my opinion, it seems a little on the delicate side for field use, so this one stays at home on the light-box. I have no complaints regarding its use in this role.

[Capocheny]

I use the Horseman 6x loupe;

Lazybones,

You have GREAT taste in loupes!

Same one I use. :)

Alternatively, a folding linen loupe is also nice... small and very compact. :)

Cheers

[Dave Parker]

I have found over the years, loupes are very personal choices, they all achieve the same end, but each and every single one of us are going to find one that fits us, I don't know what I can recommend or others can recommend is going to be the answer to your question, if your in an area that has an equipment store, your best bet is to look through as many as possible.

Happy Holidays.

Dave

[John Kasaian]

You got a lot of good answers. If what you're using now isn't cutting the mustard, experiment. What works for you is what matters. For years I used a 8x Agfa loupe without thinking anything of it---it worked. Now I use a Silvestri but it could just as easily been a Toyo, Rodenstock, Wista or Horseman (or a linen tester, for that matter!) Don't stress over it as long as you're able to focus the gg. If OTOH someone has asked you what you what for Christmas or something and you figure a new loupe is what you'd like, ask 'em how much they paid for their shoes. Never ask for a Christmas present (especially a loupe) thats going to cost more than a new pair of shoes---my 2-cents ;)

[Eric James]

After hunting high and low for strong reading glasses for ground glass evaluation I was only able to find +3 glasses "over the counter". Not finding this pair adequate I had a pair of +5 prescription reading glasses made - these worked well for most compositions but I still needed the aid of a 4x loupe fairly often.

I recently had a pair of +7 prescription reading glasses made; these allow me to get within 4 or 5cm of the GG. When your eyes are viewing an object as close as this your inter-pupillary distance decrease significantly; if you have specialty glasses like this made you should have the optician measure your pupil-to-pupil distance when your eyes have converged on the close object. The resulting prescription will allow you to view the object through both eyes; if pupil convergence isn't compensated, the brain only sees through the dominant eye.

My prescription was delayed because the lab balked at making the glasses - the technician thought that a mistake had been made, either in the optician's prescription, or in the genetic disposition of the customer who required such a screwed up pair of glasses. The optician defended her work and placed the blame with my maker.

I still carry a Canon 4x loupe but these +7 glasses are great for those who hate to fumble around with a loupe when crouched over under the cloth.

The Canon 4x loupe is a nice but expensive solution ($100US). The base is plastic so the glass won't scratch or break if you have a heavy-handed moment while focusing. It comes with a removable neck strap and case. It also makes an excellent loupe for evaluating 35mm slides. One real test of the right tool for the job is: would you replace it if it where lost of broken? I did:(

[Maris Rusis]

I still have all the focussing loupes I purchased but I no longer use them on the ground glass of my Tachiharas. Now I use 3.5 dioptre reading glasses that have been fitted with a neck cord. The glasses offer me several advantages:

They fold flat and fit in a top pocket so they are ready at hand but never feel like a painful lump against the body.

They cost $2 at the local bargain store. Loss or breakage is not a tragedy.

Focussing accuracy is already better than the unaided eye can see.

All the ground glass can be scanned quickly to keep track of what is happening everywhere on it. Loupes would enable me to focus accurately at a point but something else would be out. Fix that and something else is out. It can take a long time to focus everything with a magnifier that sees only a tiny piece of the screen at any one time.

Both hands are free. I need two hands to unlock the focussing track, turn the focussing knob, release and lock swing , shift, and tilt controls and hold onto the focussing cloth on a breezy day. Actually I need five hands so dedicating one just for holding a loupe against the ground glass really slows me down.

Light does not wait.

[Doug Dolde]

Toyo 3.6

[Michael Kadillak]

For 4x5 and 5x7 the inexpensive Toyo is all you need. All you need to do is unintentionally forget to put it in your vest and you will find that it is not always a critical accessory.

For 8x10 and larger there is absolutely no need for any focusing aid unless you are photographing in very dim lighting conditions or with the widest of wide angle lenses. Most of the time the ground glass is sufficiently large to just use your naked eyes with or without your reading glasses.

Cheers!