Are Loupes neccesary For Focusing 5x4 (Newbie)

[markbb]

Sometimes, with a brightly lit scene, I don't bother with a loupe, but truat my eye sight (under a dark cloth). However, I would find it impossible to properly focus an entire scene when using non-parallel movements (tilt etc).

 

[DannL]

Although I'm a newbie in the usage of LF cameras with "just ground glass", I couldn't live without a magnifier (loupe). Even though I've had 20/10 vision most of my adult years, I use a loupe on my 8x10 gg, every shot. It all started when I bought a Praktica FX3 35mm, which had a built-in loupe. Then I realized that every 35mm SLR I've owned technically has a loupe built-in, over the ground glass, and with the addition of a pentaprism. Food for thought.

 

[nworth]

In my experience, not usually, but when you need one, you really need it. Generally, there is enough contrast in the scene and enough depth of focus to focus wide open, stop down, and get a good shot. When that doesn't apply, a loupe helps. A lot depends on your eyes, as well. Some people find a loupe helpful all the time. BTW, use a high quality loupe. There are a lot of bad ones out there (some of them pretty expensive) that are worse than none at all. Try it out before you buy. Look for low distortion and low color fringing.

 

[kaiyen]

Okay

So how do I know if I'm focusing on the grain of the GG or the image?

And what loupe would you all recommend? I am having a hard time finding one that is a good value (gotta face the fact that I don't have much $$ to spend on this) but is of good-enough quality. anyting for less than $50?

allan

 

[matt miller]

In those rare instances when I use a loupe, I use a Toyo-View 3.6x. It is around $45 new.

 

[DannL]

Okay

So how do I know if I'm focusing on the grain of the GG or the image?

And what loupe would you all recommend? I am having a hard time finding one that is a good value (gotta face the fact that I don't have much $$ to spend on this) but is of good-enough quality. anyting for less than $50?

allan

I use a homemade loupe made from a small telescope lens and binocular objective lens stacked on a mouthwash bottle cap as the support. Hey, what can I say . . . I'm cheap ;-)

I think the depth of the gg grain is of "no account" when focusing. I may be wrong, though. I suspect it's in the micrometers and can probably be discounted when fousing?

 

[John Kasaian]

I used an Agfa loupe (about $5) for years. It works! Some people prefer Fujis (about $40) which are longer and more handy if you happen to have a folding hood or a large nose ;-)

 

[Dave Parker]

I think the depth of the gg grain is of "no account" when focusing. I may be wrong, though. I suspect it's in the micrometers and can probably be discounted when fousing?

If the ground glass is made correctly, you are very much right, the depth of the grain will not change the focal plane

Dave Parker
Satin Snow Ground Glass

 

[Dave Parker]

The "loupe" I use the most is my 10X fingerprint magnifier, that I purchase at a police liquidation auction for less than $10 bucks, it is flatfield corrected and Zeiss glass, so has proven to be as good as anything I have ever used, including my several dollar Rodenstock loupe.

Dave

 

[John Kasaian]

Did I say Fuji? I meant Toyo--- Sorry! My current loupe is a Silvestri which is(or was) about $70 and is very nice to use, but the Agfa has high magnification which I prefer I guess because I'm used to it. You may still find some Agfa loupes floating around after the ship sank. Get one and you won't be disappointed. If you don't like using it on your gg they come in handy for evaluating negatives or as a 'back up' for a more expensive loupe (if thats the route you travel) and for $5 or so it'll be one of the cheapest LF gizmos you'll ever buy.

 

[nworth]

I've found that the Bausch and Lomb 7X Hastings Triplet magnifiers (available from Edmund Scientific in the US, among other places) are excellent. 7 to 10X is about all the magnification you can use. I also have a couple of three lens magnifiers I picked up in a variety store that work well. (They restrict you to the central part of the lenses at the highest magnification, which eliminates a lot of aberations. I think both originally came from B&L as well.) There just doesn't seem to be much relation between quality and price here. What you find in a photo store may or may not be usable or overpriced.

 

[noseoil]

I use the toyo loupe and am very happy with it. Nice to have a rubber edge to rest on the glass and a longer tube so my hat doesn't bump the camera. A friend uses the cheap 3x reading glasses from a drugstore. I tried them, and found that I felt like I needed dramamine for motion sickness when using them, so the loupe is best for me. If you are young enough, you can just use your eyes, as they focus well from near to far without any help. tim

 

[Early Riser]

I've used and owned most of the loupes out there, from the little cheap agfa loupe that was ubiquitous when I was a photo student, to fabric magnifiers, schneider 4x, rodenstock 4x (too bulky), rodenstock 8x (too tiny and short), mamiya zoom 4x-12x (colossal! and $$$$), the toyo 3x (very nice, tall good head to GG clearance) and currently the horseman 7x (great head to GG clearance). My pick are the last 2 for GG work.

I don't care how good one's eyes are, you're simply not going to be able to focus as well and as consistently than someone using a loupe. There is one risk though when using a loupe, you have to be careful not to lean on the camera back (GG) when using the loupe as you will physically move the apparent plane of focus.

 

[jbbooks]

"If you have a Crown Graphic that won't take sharp pictures, the first thing to check is the assembly of the ground glass - fresnel lens underneath with etched side facing out (i.e. to the back of the camera), GG on top with etched side facing in (towards the front of the camera). It's more than possible someone has put the fresnel on top of the GG."

"What is the Proper Placement of the Fresnel? One subject which comes up often is the correct position of the fresnel lens. In years past, several arrangements have been used, including placing the fresnel behind the ground glass, in front of the ground glass, and incorporated into a ground glass made of plastic. However, there is only one correct arrangement. The ground glass surface should face the camera lens, and the fresnel is placed behind it, on the outside of the camera, toward the photographer. The textured surface of the fresnel should be placed against the ground glass."--Ron Wisner

 

[Dave Parker]

"If you have a Crown Graphic that won't take sharp pictures, the first thing to check is the assembly of the ground glass - fresnel lens underneath with etched side facing out (i.e. to the back of the camera), GG on top with etched side facing in (towards the front of the camera). It's more than possible someone has put the fresnel on top of the GG."

"What is the Proper Placement of the Fresnel? One subject which comes up often is the correct position of the fresnel lens. In years past, several arrangements have been used, including placing the fresnel behind the ground glass, in front of the ground glass, and incorporated into a ground glass made of plastic. However, there is only one correct arrangement. The ground glass surface should face the camera lens, and the fresnel is placed behind it, on the outside of the camera, toward the photographer. The textured surface of the fresnel should be placed against the ground glass."--Ron Wisner

Thanks for this, but there are many of us, that disagree with Ron's assesment of the proper placement of the fresnel, in the graflex cameras the fresnel was placed in front of the ground glass on the lens side, and the bosses machined into the backs of the graflex cameras bear this truth out, so the disscussion of fresnel placement still is a long winded and controversial subject.

Dave Parker
Satin Snow Ground Glass
Focus on the Picture, Not on the Glass

 

[David H. Bebbington]

"If you have a Crown Graphic that won't take sharp pictures, the first thing to check is the assembly of the ground glass - fresnel lens underneath with etched side facing out (i.e. to the back of the camera), GG on top with etched side facing in (towards the front of the camera). It's more than possible someone has put the fresnel on top of the GG."

"What is the Proper Placement of the Fresnel? One subject which comes up often is the correct position of the fresnel lens. In years past, several arrangements have been used, including placing the fresnel behind the ground glass, in front of the ground glass, and incorporated into a ground glass made of plastic. However, there is only one correct arrangement. The ground glass surface should face the camera lens, and the fresnel is placed behind it, on the outside of the camera, toward the photographer. The textured surface of the fresnel should be placed against the ground glass."--Ron Wisner

I should make it clear that the arrangement I am talking about applies only to Graphic cameras - in any 4x5" other camera that I own or have owned, the fresnel lens should be placed "normally", i.e. GG closer to the lens, ground surface facing towards the lens, and with any fresnel lens on top of this, i.e on the outside, and with the fresnel rings facing inwards towards the GG.

Moreover, Ron Wisner's remarks would seem to apply to the THEORETICALLY correct ideal placement of a fresnel lens - if you're MAKING cameras, you can of course please yourself which approach to take, if you have a ready-made camera, you must put the fresnel where the maker intended.

 

[carsten]

I print huge enlargements and to have a razor sharp negative is not an option, so I always use a loupe. 99% of my work is done using a 4x Schneider loupe (or an old 4x folding magnifier originally intended to check the threads of a fabric). In critical focusing situations I have a Linhof/Schneider 8x.
I really don't like the GG with Fresnel screen. I have it on my Technika 4x5. It makes focusing more difficult.

 

[Jim Noel]

I always use a loupe.
As far as a dark cloth is concerned, use a black T-shirt. The neck of Large, or X-Large fits around the camera back and it blocks light not only from above, but also that reflected from the ground. Small, light weight and cheap.
Jim

 

[jbbooks]

From the comments following my earlier one:

“Thanks for this, but there are many of us, that disagree with Ron's assesment of the proper placement of the fresnel, in the graflex cameras the fresnel was placed in front of the ground glass on the lens side, and the bosses machined into the backs of the graflex cameras bear this truth out, so the disscussion of fresnel placement still is a long winded and controversial subject.”

and, the other, with my emphasis added,

“I should make it clear that the arrangement I am talking about applies only to Graphic cameras - in any 4x5" other camera that I own or have owned, the fresnel lens should be placed "normally", i.e. GG closer to the lens, ground surface facing towards the lens, and with any fresnel lens on top of this, i.e on the outside, and with the fresnel rings facing inwards towards the GG. Moreover, Ron Wisner's remarks would seem to apply to the THEORETICALLY correct ideal placement of a fresnel lens - if you're MAKING cameras, you can of course please yourself which approach to take, if you have a ready-made camera, you must put the fresnel where the maker intended.”

Not being aware that Graflex intended otherwise, I posted a partial quote from Wisner that seemed sufficient to address the issue. After reading your comments, I tried to ascertain why the Graphic should be any different from any other view camera using a ground glass. I looked long enough to satisfy myself that your description of the method for installing the surfaces in the Graphics is the consensus view. Unfortunately, however, I was not able to find anything definitive concerning the installation with Graflex as an original source. Everything I found was second or third hand, the most authoritative source(s) being someone claiming experience in the repair of Graphics.

Nevertheless, I would like to point out that there does not seem to be any difference between what you describe as the “normal” way and what you describe as Wisner’s “theoretical” way to install the surfaces. Comparing the two, they are the same. The question, then, seems to be why the Graphic way is different from the “normal” or “theoretical” which you, apparently, justify by its construction. The way you, the consensus, would arrange the surfaces has two problems. First, it requires one to think that the Fresnel works better with its surfaces turned around. Why? If the Fresnel surface works better with its ribbed surface away from the lens (which is counter-intuitive), why not always have it that way? If not, why change it? Why only reverse it on a Graphic? Second, since what you describe as the “normal” way and Wisner’s theoretical way are the same, what is the reason for reversing them in the Graphic? If Wisner is correct and the distance from the lens to the film plane must be the same as the distance from the lens to the diffusion surface (the rough side of the ground glass) and you are correct (that the Graphic is built differently than Wisner chose to build his cameras), then a couple of measurements ought to confirm this. In fact, when I measure the distance from the lens to the filmholder septum and the distance from the lens to the first glass surface of the Graphic, they are the same.

In other words, there is nothing about the construction of the Graphic, mine, anyway, that prevents you from installing the GG and the Fresnel in the normal way while having the distance from the diffusion surface of the GG to the lens identical to the distance of the film septum of the filmholder to the lens, which is Wisner’s prime requirement.

Placing the GG in closest to the lens, with the rough side toward the lens and the Fresnel on the outside of the GG, furthest from the lens, with the ribbed side toward the GG leaves the film to lens and the diffusion surface to the lens distances identical and conforms to both the “normal” method of installation and all of Wisner’s theoretical requirements. Why, then, are we to conclude that Graflex required it to be done any differently? What is the basis for the “consensus” opinion that it should be done as you describe with the Fresnel in front turned backwards with the smooth side towards the lens and with the GG in back at a distance that is different from the distance of the lens to the film septum?[/I]

The article I quoted from can be found here, http://www.wisner.com/viewing.htm.

 

[kswatapug]

I used to think I could focus without the benefit of a loupe, but after checking my SWAGs often enough, it was clear to me that I wasn't nearly as sharp-sighted as I had thought. Mine's a 10X Schneider. If I had to do it over, I'd probably go with a 4X.

FWIW dustym, there is a model BLACKJACKET(TM) designed for SLR style cameras. It has two necks, one for the lens and one for the tripod-mounted camera. It's intended market was for the d****l crowd, who, in spite of all the gadgetry, at least share the age old need of shading the camera back in bright conditions so they can see what they are up to.

 

[Dan Fromm]

From the comments following my earlier one:

<snip>
In fact, when I measure the distance from the lens to the filmholder septum and the distance from the lens to the first glass surface of the Graphic, they are the same.

In other words, there is nothing about the construction of the Graphic, mine, anyway, that prevents you from installing the GG and the Fresnel in the normal way while having the distance from the diffusion surface of the GG to the lens identical to the distance of the film septum of the filmholder to the lens, which is Wisner’s prime requirement.

<snip>Why, then, are we to conclude that Graflex required it to be done any differently? What is the basis for the “consensus” opinion that it should be done as you describe with the Fresnel in front turned backwards with the smooth side towards the lens and with the GG in back at a distance that is different from the distance of the lens to the film septum?[/I]

The article I quoted from can be found here, http://www.wisner.com/viewing.htm.

Look, the fresnel was an option with Graphics. Graflex Inc. sold cameras with fresnel and without fresnel. I have a pair of 2x3 Graphics with Graflok backs. One's focusing panel has a fresnel, the other's doesn't. The two focusing panels have the same casting number. In the one with fresnel, the fresnel sits on the lens side of the focusing panel, grooved side facing the film; the GG sits on the film side of the fresnel, ground side facing the lens. In the one with no fresnel, the GG sits on the focusing panel, ground side facing the lens.

In both focusing panels, the fresnel + GG and GG alone, respectively, sit on bosses that are part of the casting. The bosses in the focusing panel with fresnel are LOWER than the ones in the focusing panel without. This puts the GG in the right place, with compensation for the fresnel's thickness and refractive index. If I simply removed the fresnel and put the GG back on the bosses, I'd misfocus every time. If I put a fresnel in front of the GG in my focusing panel with HIGH bosses, I'd misfocus consistently but in the opposite direction.

Yes, its confusing. Graflex made two different parts with the same casting number. If you don't understand my explanation, ask again. Tersely. And before you ask again, please reread Dave's answer.

 

[Dave Parker]

Well, I ain't tooting my horn here at all, but I do happen to have a bit of information on the function and design of camera backs, and I disagree with Wisner and many others on this particular subject of fresnels, not if they should be used, some like them and some don't, but in the design of the camera back determines what is "Normal" Ron Wisner took it upon himself to proclaim what is "normal" which in many instances might not be right, What determines right is the nature of the mounting position for the particular camera and how it was designed, secondary is the skill in which the person has that is mounting the fresnel, if you have the capibilites to mount the fresnel on the lens side of the glass, then this may be the "normal" but understand, the only reason the fresnel is used, is to increase light transmission, which can in certain instances enhance the image you are focusing on.

Dave

 

[BradS]

I have and often use a pair of 3.0 power reading glasses. They cost me all of $9.95 at Walmart. They serve the purpose and the user interface is much more friendly than that of the fancy loupe that I have and rarely use.

 

[BradS]

Oh, hey guys....incidently, the conversation seems to have been derailed. I mean all this talk about the fresnel lens placement is interesting and all but....perhaps it deserves its own thread?

 

[sanking]

Are loupes necessary for precision work with view cameras?

No.

Depends a lot of format, plane of focus, and depth of field.

I usually use a loupe with 5X7, especially if most of the subject is on a fairly narrow plane of focus. I rarely ever use a loupe for ULF. With ULF I find it much more important to look at the whole screen when focusing in order to determine the best point of focus in order to obtain maximum depth of field.

Sandy

In those rare instances when I use a loupe, I use a Toyo-View 3.6x. It is around $45 new.