Wista ground glass question.

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Soulstar89

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Hi everyone,

Happy new year!!!

I have a wista 45vx with a 150mm lens and I feel like I would like a brighter screen. I have to be directly in the centre and around 30-40cm otherwise it’s dim. I notice it more in open shade outside. The ground glass is a made with 6x9 frame and then had another piece on top with black grids. I’ve attached a picture of my ground glass.

I’ve done some research and fresnel lenses are normally placed on top of the ground glass. I really like the grid on the second glass for leveling things. I tried to unscrew the bracket holding the two glasses in place but couldn’t loosen the screws.

Is it possible to keep the two pieces of glass and just add a fresnel lens? Does fresnel glass ever come with black lines? I’ve only seen translucent lines.

This is my first 4x5 camera so I have very little experience in these things. Your guidance would be much appreciated.

I also need to find a decent dark cloth and upgrade my peak x5 lupe to a proper one.IMG_0852.jpeg
 
I would check the nature of your existing ground glass first before you do anything else, because from the photo above it looks like your ground glass already has a fresnel built in - hence the concentric rings visible against the sky there, and the image in general is far too evenly lit than you'd normally see from a phone photo of a plain ground glass. In fact I would put money on this being the case, which would explain the need to be central and at a specific distance to see it properly. If it is a plastic screen with a fresnel built in (which might also explain the need for the cover glass) it would be consistent with the sort of screen that some Wistas and Tachiharas apparently came with (again, same as Chamonix and Ebony do/did) then adding an additional fresnel might over-correct it, making it unusable except with super wides.
 
Dave thank you for sharing this. You are right it does seem to have a slight rings going around the ground glass in some Angles.


like you said wista did have a option with a combination of ground glass and fresnel. I saw an old page on b&h and the glass was 300!!

From what you have written am I correct in thinking that maybe this screen is suited for lenses more north of 150mm?

How would you recommend I tackle my slight problems? My aim is a lens setup of 90,135,210 is wanting to mix 4x5 and 6x12. Maybe even wider for 6x12.
 
I agree with Dave.

Ground glass without a fresnel lens has a very noticeable hot-spot, especially with wide angle lenses and your ground glass looks very evenly lit by comparison.

Ground glass can be plain or with grid lines and with or without markings for the use of roll film backs.

However, if the difficulty is composition, then a (right-angled) reflex viewerfinder may be a great aid. I use them regularly. They weigh next to nothing but add a bit of extra bulk.

If focus is the issue, I would have thought the x5 peak was ideal. I use a peak x4 and a long schneider x7.
 
MartyNL said:
I agree with Dave.

Ground glass without a fresnel lens has a very noticeable hot-spot, especially with wide angle lenses and your ground glass looks very evenly lit by comparison.

Ground glass can be plain or with grid lines and with or without markings for the use of roll film backs.

However, if the difficulty is composition, then a (right-angled) reflex viewerfinder may be a great aid. I use them regularly. They weigh next to nothing but add a bit of extra bulk.

If focus is the issue, I would have thought the x5 peak was ideal. I use a peak x4 and a long schneider x7.
Click to expand...

Hey Marty,

I just took off the ground glass section like you were to put a roll film back on. It definitely is the mixed ground glass with fresnel. I placed it up against a light and the rings was clear to see.

I’ll look into the right angle. Tbh I’ve been in home studio up until recently. I do feel in a very controlled environment it could help with things being the right way around.

The loupe is ok when the subject is lit well. I had zero issues when talent under a modelling light. It is made of plastic compared to actual glass though. Any advise on dark cloths?

I’m still learning and trying to find out what I works for me.

Really appreciate these forums.
 
I rarely use a dark cloth for 4x5. I only have a Linhof heavy cotton one with lead weighted seams! Pretty industrial!

I've often thought about one of the 'newer' more modern types, ultra lightweight material, waterproof, breathable, heat reflective with zip/draw cord/velcro etc.

But to be honest, I get along really well with my right-angled reflex viewerfinders. The Linhof one's have a built-in x4 magnifier and are 4-way, meaning the eye-piece can be rotated 90°, 180°, 270°, 360°.

Equally, they're not everyone's cup of tea. Some feel upside down and back to front, stimulates the brain and benefits composition.

In my case, images are flipped the right way around, there's no flapping in the breeze and there are little to no light leaks and reflections.
 
Soulstar89 said:
Dave thank you for sharing this. You are right it does seem to have a slight rings going around the ground glass in some Angles.


like you said wista did have a option with a combination of ground glass and fresnel. I saw an old page on b&h and the glass was 300!!

From what you have written am I correct in thinking that maybe this screen is suited for lenses more north of 150mm?

How would you recommend I tackle my slight problems? My aim is a lens setup of 90,135,210 is wanting to mix 4x5 and 6x12. Maybe even wider for 6x12.
Click to expand...
It's likely to be the opposite; it was probably designed for lenses shorter than 150mm, simply because it's those focal lengths which benefit most from a fresnel. It would also make sense on a Wista or other field-type camera since the assumed use for these is outdoors for landscape/nature etc. However, it's hard to know since manufacturers rarely (if ever?) actually make this clear.

So assuming the fresnel is geared up to be best for wide-to-normal lenses, then with a 90/135/210 setup I'd expect it to be great for 90 and 135 but a bit weird for 210mm. BTW this is the same for the Maxwell screen I have - very even illumination for wide-to-normal lenses, but an odd sort of reverse hotspot for 240mm i.e. overcorrected for long lenses. It's just the nature of fresnel lenses, they are best at a specific focal length (which is never declared by the manufacturer) and the further away from this you go the weirder they get.

However, if you went to using a plain screen then I'd expect that it would be fine for a 210mm lens, usable but not great for 135mm, and basically unusable for 90mm. So your current setup is probably, on balance, much preferable to this, so you might be best just learning to live with it. One thing some people do is get hold of a spare focussing screen frame (the bit that unclips on a graflok back) and carry just a plain screen on the spare, to swap to for longer lenses, but finding the spare parts can be hard, and on some cameras that part doesn't unclip anyway.

If you can get your screws undone you could try other combinations of fresnel and plain screen, or combined screens, but since you rarely really know what you're going to get before buying one it's trial and error. Also sometimes brighter screens can be easier for composing but not have the same 'snap' in and out of focus - the Maxwell screen and the Hasselblad AcuteMatte screens are a bit like this, as are modern DLSR screens designed for AF lenses. There's always a big slice of personal preference involved and trade-offs.

A right angle viewer would keep your eye centred at least, but for me it would be a ball ache then having to remove it to get your loupe onto the screen for critical focus. And as soon as you tilt you'll need to be moving your head around to see the image properly anyway, so I wouldn't bother with one. I had a Cambo one for years and it never left the house except on a rigid fixed 65mm helical camera for this reason.
 
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The Wista combination screen & fresnel is actually one of the brightest available, I've been using my Wista 45DX with a similar screen etc since 1986/7. It's great with lenses from 75mm upwards, 90mm, 135mm/150mm, 210mm, 240mm,even a 300m. It's nor so good with my 65mm, but then I can't remember when I last used it, as I prefer my 75mm.

I don't have the problem @Dave_P describes with the Wista screen, if I use my 240mm Nikkor W, 300mm Nikkor M, or 360mm Tele-Xenar, lenses. Likewise, no issues with my Toyo, and screen/fresnel. That might be a peculiarity of the Maxwell screen.

Morco still had some 5x4 Beattie Intenscreens just over a t=year ago, these were probably the brightest screens available, but rather expensive, I have a 10x8 Intenscreen that came NIB with my first Agfa Ansco camera, it's easy to use.

I make focus screens, and also fit fresnels, I started while living abroad and noticing how very dim the screen on my Crown Graphic was compared to my Wista, it was over 3 stops different overall. With a new screen and then a fresnel, I got close to the Wista screen brightness.

It's worth adding that the Wista screen like a Beattie Intenscreen is in fact a fresnel, ground on the reverse side, with a protective glass cover, so not a separate ground glass screen & fresnel, that's why it's brighter. Double check the screen is fitted correctly, with the GG side towards the lens.

1735921239885.png

Looking at this diagram, it's easy to see why these screens work well with different focal length lenses.

Ian
 
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Because the Fresnel sheet is flat, it’s easy to forget that it is, in fact, a lens. Consequently it will focus the available light to a point. That’s where it seems brightest to you. There’s no way to ameliorate this entirely. Ye canna’ break the laws o’ Physics. If you use the rising front you’ll find that this optimum spot moves too - towards the top of the image, which is confusingly downwards on the camera.
People seem to vary very widely in their ability to see the screen in dim light. I suppose it’s like the other senses; some people have very acute hearing, for example.
A darkcloth is always useful. Not only for keeping in the darkness but for keeping rain off the camera if it’s wet, or keeping wind off the photographer if it’s chilly. Handy for wrapping fragile equipment and for sitting on cold damp ground. Some of them seem remarkably expensive so best to improvise with almost any old rag until you find what’s important to you.
A 5x loupe seems fine. Can you adjust the point of focus on the one you have? It should be focused on the ground surface of the ground glass.
 
@Ian Grant What I was saying could well be a Maxwell issue, although they are subject to the same laws of physics as other screens. I will have to compare it to the stock Chamonix screen (from memory this is a Wista-esque combo screen).

I also have no idea whether my Maxwell is a general purpose one or a wide-specific one as I bought it online for relatively cheap off some bloke on a forum (they are good but not worth the normally huge pricetag). The problem with the whole buying-a-screen affair is that the whole business is rather opaque (pun intended) when it comes to what you're actually buying and what focal length or lengths any given fresnel is set up for, and how that's going to gel or otherwise with your own preferences or expectations.
 
Dave_P said:
I also have no idea whether my Maxwell is a general purpose one or a wide-specific one as I bought it online for relatively cheap off some bloke on a forum (they are good but not worth the normally huge pricetag).
Click to expand...

I bought one of Mr Maxwell's screens and have used it successfully from 72mm to 400mm(tele)
 
Dave_P said:
It's likely to be the opposite; it was probably designed for lenses shorter than 150mm, simply because it's those focal lengths which benefit most from a fresnel. It would also make sense on a Wista or other field-type camera since the assumed use for these is outdoors for landscape/nature etc. However, it's hard to know since manufacturers rarely (if ever?) actually make this clear.

So assuming the fresnel is geared up to be best for wide-to-normal lenses, then with a 90/135/210 setup I'd expect it to be great for 90 and 135 but a bit weird for 210mm. BTW this is the same for the Maxwell screen I have - very even illumination for wide-to-normal lenses, but an odd sort of reverse hotspot for 240mm i.e. overcorrected for long lenses. It's just the nature of fresnel lenses, they are best at a specific focal length (which is never declared by the manufacturer) and the further away from this you go the weirder they get.

However, if you went to using a plain screen then I'd expect that it would be fine for a 210mm lens, usable but not great for 135mm, and basically unusable for 90mm. So your current setup is probably, on balance, much preferable to this, so you might be best just learning to live with it. One thing some people do is get hold of a spare focussing screen frame (the bit that unclips on a graflok back) and carry just a plain screen on the spare, to swap to for longer lenses, but finding the spare parts can be hard, and on some cameras that part doesn't unclip anyway.

If you can get your screws undone you could try other combinations of fresnel and plain screen, or combined screens, but since you rarely really know what you're going to get before buying one it's trial and error. Also sometimes brighter screens can be easier for composing but not have the same 'snap' in and out of focus - the Maxwell screen and the Hasselblad AcuteMatte screens are a bit like this, as are modern DLSR screens designed for AF lenses. There's always a big slice of personal preference involved and trade-offs.

A right angle viewer would keep your eye centred at least, but for me it would be a ball ache then having to remove it to get your loupe onto the screen for critical focus. And as soon as you tilt you'll need to be moving your head around to see the image properly anyway, so I wouldn't bother with one. I had a Cambo one for years and it never left the house except on a rigid fixed 65mm helical camera for this reason.
Click to expand...

I went out today to the same spot and it was miles easier to focus due to ever so slightly more open shadows.

I took three shots then went to check out some FUJINON lenses. I tried the 105mm, 125mm and 135mm. No fall off whatsoever so ever when going wider.

I picked up the 135mm 5.6. Back home the 135mm has a much bigger spread of the brightness compared to my 150mm. Weird.

Today shows I need to shoot and practice more.

Appreciate the input
 
Ian Grant said:
The Wista combination screen & fresnel is actually one of the brightest available, I've been using my Wista 45DX with a similar screen etc since 1986/7. It's great with lenses from 75mm upwards, 90mm, 135mm/150mm, 210mm, 240mm,even a 300m. It's nor so good with my 65mm, but then I can't remember when I last used it, as I prefer my 75mm.

I don't have the problem @Dave_P describes with the Wista screen, if I use my 240mm Nikkor W, 300mm Nikkor M, or 360mm Tele-Xenar, lenses. Likewise, no issues with my Toyo, and screen/fresnel. That might be a peculiarity of the Maxwell screen.

Morco still had some 5x4 Beattie Intenscreens just over a t=year ago, these were probably the brightest screens available, but rather expensive, I have a 10x8 Intenscreen that came NIB with my first Agfa Ansco camera, it's easy to use.

I make focus screens, and also fit fresnels, I started while living abroad and noticing how very dim the screen on my Crown Graphic was compared to my Wista, it was over 3 stops different overall. With a new screen and then a fresnel, I got close to the Wista screen brightness.

It's worth adding that the Wista screen like a Beattie Intenscreen is in fact a fresnel, ground on the reverse side, with a protective glass cover, so not a separate ground glass screen & fresnel, that's why it's brighter. Double check the screen is fitted correctly, with the GG side towards the lens.

View attachment 5030

Looking at this diagram, it's easy to see why these screens work well with different focal length lenses.

Ian
Click to expand...
Cheers for sharing this.

My mamiya rz67 focusing screen is very much like the Beattie screen with the micro prism in centre.

If I ever decide to change I’ll drop you a message.
 
David M said:
Because the Fresnel sheet is flat, it’s easy to forget that it is, in fact, a lens. Consequently it will focus the available light to a point. That’s where it seems brightest to you. There’s no way to ameliorate this entirely. Ye canna’ break the laws o’ Physics. If you use the rising front you’ll find that this optimum spot moves too - towards the top of the image, which is confusingly downwards on the camera.
People seem to vary very widely in their ability to see the screen in dim light. I suppose it’s like the other senses; some people have very acute hearing, for example.
A darkcloth is always useful. Not only for keeping in the darkness but for keeping rain off the camera if it’s wet, or keeping wind off the photographer if it’s chilly. Handy for wrapping fragile equipment and for sitting on cold damp ground. Some of them seem remarkably expensive so best to improvise with almost any old rag until you find what’s important to you.
A 5x loupe seems fine. Can you adjust the point of focus on the one you have? It should be focused on the ground surface of the ground glass.
Click to expand...
Hey David,

My peak lupe is the plastic one for viewing negs on a light box. Im going to pickup a etone dark coth. I encountered your example of having equipment a place to rest today. Need to get better. Only way is shoot more. Lol
 
Soulstar89 said:
I went out today to the same spot and it was miles easier to focus due to ever so slightly more open shadows.

I took three shots then went to check out some FUJINON lenses. I tried the 105mm, 125mm and 135mm. No fall off whatsoever so ever when going wider.

I picked up the 135mm 5.6. Back home the 135mm has a much bigger spread of the brightness compared to my 150mm. Weird.

Today shows I need to shoot and practice more.

Appreciate the input
Click to expand...

Just curious, was the 105mm the f5.6 or f8?
 
MartyNL said:
Just curious, was the 105mm the f5.6 or f8?
Click to expand...
It was the f8 nsw. The lens has a 250mm image circle and 77 filter thread. Wasn’t much difference in brightness to my 135mm I picked up tbh. Heavy lens though. My wista couldn’t hold it’s position unless I locked the knob at full rise lol.
 
Soulstar89 said:
It was the f8 nsw. The lens has a 250mm image circle and 77 filter thread. Wasn’t much difference in brightness to my 135mm I picked up tbh. Heavy lens though. My wista couldn’t hold it’s position unless I locked the knob at full rise lol.
Click to expand...
Hi, I could be interested in that lens, could you PM me the details, please?
 
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