Viewfinder flare, effect of recessed windows ?

maddoc

... likes film again.
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I take a lot of photos at night in bars / at events so a flare-free VF is quite essential for me. This was one of the reasons to substitute my M6 with an MP (same 0.72x VF). Now having the M4-P for a while (the first M where Leica installed the "cheaper" VF being more prone to flare), I was astonished that flare is not a problem as it was with the M6.

Wondering why that could be, I thought about the effect of a lens hood, giving shade against light of a bright source just outside of the frame. Looking at my M4-P with recessed windows (and having a matte black top-plate), I got the idea that the frame of the small RF window works similar to a lens hood, giving some shade to the small window and thus preventing flare. The M6 has the flushed windows, where light from a broader angle can enter the RF window, thus more prone to flare.

Does it sound weird ?
 
As far as I understood from my own little online research on the matter, the difference is in internal optical construction of the finders. There is an additional optical element in RFs of classic Ms (M3 up to M4 with its siblings) that actually caused to suppress the flare. M6 original RF doesn't have that particular element (probably due to Leica efforts to keep pricing more reasonable) and according to the common wisdom that is what allowed flare in.
I have a beater M3 aside of M6 and shootign with M3 I just forgot about RF flaring altogather. My M6, on the other hand, flares quite a lot in an appropriate lighting, I consider getting it RF upgraded to a non-flaring MP finder at some later stage.
 
I've an M4, which according to theory should be relatively flare resistant. But especially indoors, when a light hits the VF/RF windows under just the right angle, the finder whites out completely.. Never had that on the HexarRF
 
pvdhaar said:
I've an M4, which according to theory should be relatively flare resistant. But especially indoors, when a light hits the VF/RF windows under just the right angle, the finder whites out completely..


That's interesting. I have never had a flare problem with my M4. In situations where my M6 was flaring, I have often pulled out the M4 and had no problem at all.
 
My M6TTL flares badly--so much so, that I've been thinking of getting rid of it and going with an M7, MP, or perhaps a Ziess Ikon. Other than the VF Flare, the M6TTL is damn near perfect, but the VF patch flare is unforgivable.

My M3 has never flared under any conditions.
 
I too find that interesting about the M4 flare. I have never had a flare problem with my M2, which I believe has the same finder as the M4? I have even tried to find a condition to make the viewfinder flare - I just make my M6 flare then pick up the M2 and point it at the same thing, never been able to get flare with this method.

You have given me an idea, regarding the recessed window though. Has anyone attemped creating a hood around the viewfinder? I'm thinking of trying silly putty or something like that to create a low profile shade around the finder.
 
like2fiddle said:
You have given me an idea, regarding the recessed window though. Has anyone attemped creating a hood around the viewfinder? I'm thinking of trying silly putty or something like that to create a low profile shade around the finder.
That was exactly what I wanted to ask but forgot to write.... :eek: I don't have an M6 / M6 TTL at the moment but how about this simple test: Cutting a frame out of some black 1mm thick plastic / card board and sticking it around the small RF window ? If the recessed windows have any effect this should do the trick.
 
Rafael said:
That's interesting. I have never had a flare problem with my M4. In situations where my M6 was flaring, I have often pulled out the M4 and had no problem at all.
I must say it doesn't happen often, but it's when light comes from one particular angle at the upper left (outside of the view in the finder itself), then it's sort of like megaflare.. It's not just the patch that's invisible, it's the complete finder that whites out..
 
pvdhaar said:
I must say it doesn't happen often, but it's when light comes from one particular angle at the upper left (outside of the view in the finder itself), then it's sort of like megaflare.. It's not just the patch that's invisible, it's the complete finder that whites out..

This sounds strange to me. Did you ever had your M serviced / cleaned ? Your problem sounds like cleaning is nessecary ...
 
None of my M's flares. I have an M2 and two M4s. Peter, I wonder if your's had a VF "fix"...
 
maddoc said:
This sounds strange to me. Did you ever had your M serviced / cleaned ? Your problem sounds like cleaning is nessecary ...
My M4 has been completely overhauled/restored by Wil v. Maanen in 2006. It's as clean as a whistle.. Heck, maybe it's just too damn clean! Or perhaps I'm just a bit too exacting of it. It only happens indoors when there's a single light in a confined particular location and I'm viewing into an almost dark area.. But the situation where it occurs is so singular that you have to work really hard to angle the camera in exactly that position.. It's not ever happened under any normal life circumstance.. So I'm not surprised many won't ever run into it in years of shooting.
 
pvdhaar said:
My M4 has been completely overhauled/restored by Wil v. Maanen in 2006. It's as clean as a whistle.. Heck, maybe it's just too damn clean!

Yes, Will does a good job! Perhaps our M4s met at Will's. Mine was CLAd by him in 2006 as well :)
 
HuubL said:
Yes, Will does a good job! Perhaps our M4s met at Will's. Mine was CLAd by him in 2006 as well :)
Perhaps they'll meet again over there 35 years down the road.. he has made mine run smooth like in new condition. I'm sure it'll hold up for a couple of decades again (how's that for value for money..)..
 
HuubL said:
Yes, Will does a good job! Perhaps our M4s met at Will's. Mine was CLAd by him in 2006 as well :)
Will two M4's make a M8? ;)

Back to the original problem, maddoc mentioned cutting some plastic to improve the situation. Leicagoodies has a little thing they call the Shade which supposedly solves this problem. From what I gather, it's some kind of polarising material. I got one lying around but I haven't tried it yet.
 
Same experience as pvdharr one time since I bought them new in 198? when they first came out. Indoor shot, Single light to upper left corner outside the view. Lost the RF patch. I shielded the VF, focused, and kept going.
 
As others have posted, I believe it's the internal construction of the finders that are different, assuming there's some difference between the M4-P & later finders (perhaps someone could ask DAG or Sherry Krauter). I seriously doubt the recessed windows of the pre-M6 cameras account for any difference in flare as they aren't recessed very much @ all (in fact, they aren't recessed so much as the bodies have a rims around the VF & RF windows).

FWIW, when I had an M2, I could get it to flare in certain situations, not as bad as my M6 TTL & M7 before I had the flare fix installed (& certainly not a complete finder whiteout like pvdhaar describes), but still noticeable. With the flare fix, I find the M6 TTL & M7 to be almost, but not quite, as flare-resistant as the M2.

maddoc said:
I take a lot of photos at night in bars / at events so a flare-free VF is quite essential for me. This was one of the reasons to substitute my M6 with an MP (same 0.72x VF). Now having the M4-P for a while (the first M where Leica installed the "cheaper" VF being more prone to flare), I was astonished that flare is not a problem as it was with the M6.

Wondering why that could be, I thought about the effect of a lens hood, giving shade against light of a bright source just outside of the frame. Looking at my M4-P with recessed windows (and having a matte black top-plate), I got the idea that the frame of the small RF window works similar to a lens hood, giving some shade to the small window and thus preventing flare. The M6 has the flushed windows, where light from a broader angle can enter the RF window, thus more prone to flare.

Does it sound weird ?
 
furcafe said:
I seriously doubt the recessed windows of the pre-M6 cameras account for any difference in flare as they aren't recessed very much @ all (in fact, they aren't recessed so much as the bodies have a rims around the VF & RF windows).
This was my point about this thread. The windows are not recessed much (roughly 1 mm or so) but would it be sufficient to prevent from flare ? I observed flare with my M6 usually when a bright light source was just outside the VF frame. If the camera then was rotated (e.g. horizontal -> vertical orientation) the flare effect disappeared and the focus path became visible again. Based on this experience I thought about a possible shading effect.

Starting with the M4-2 a condenser lens was removed form the RF / VF setup and later re-inserted in the MP / M7 VF (together with some other small modifications as painting the outer prism surfaces to supress stray light effects)
 
No, I completely understand your point & am aware of the changes made in the M series RF/VF starting w/the M4-2, I was just being skeptical that the slight recess of the RF window on your M4-P makes any practical difference. ;) To use your example, if the recess made a difference re: RF patch flare, I don't see why rotating the camera should make a difference. Isn't the window recessed @ the same depth all away around?

maddoc said:
This was my point about this thread. The windows are not recessed much (roughly 1 mm or so) but would it be sufficient to prevent from flare ? I observed flare with my M6 usually when a bright light source was just outside the VF frame. If the camera then was rotated (e.g. horizontal -> vertical orientation) the flare effect disappeared and the focus path became visible again. Based on this experience I thought about a possible shading effect.

Starting with the M4-2 a condenser lens was removed form the RF / VF setup and later re-inserted in the MP / M7 VF (together with some other small modifications as painting the outer prism surfaces to supress stray light effects)
 
The flare "problem" started part way through M4-2 production, as noted above. The M4-2 and most M4-Ps have brass tops with the recessed windows. The worst flaring M I've owned was a brass M4-P, so I really don't think that the flush vs recessed window thing makes any difference.
 
Rotating the camera makes all the difference, because there is a diffractor (?) in the front face of the camera. This makes the light falling in more diffuse. But, this diffractor is made up of vertical prisms. Therefore the effect is completely different when rotated.
 
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