Leica Film M: "Boxed" flare when the Sun is in the frame - Shutter issue?

[coelacanth]

I noticed this "boxed" flare when the Sun is in the frame. I run a test roll and confirmed this is happening only when the Sun is in the frame, and not visible when it's right outside. Only observed with 1/1000 shutter speed, but not sure if this would happen at 1/500 or below as I haven't tested that.

The camera (modern MP) is not exhibiting this or other obvious shutter issues in other conditions even if it's a bright scene. I've been careful pointing the camera at the sun only for a split second and there is no visible damage or a hole on the shutter curtains.

Could it be a shutter issue? Or this is somewhat expected/could happen to an M body? The entire test roll had several sets of repeated settings to eliminate one-off issues, and all frames with sun in the shot had basically the same boxed flare. I've had many M bodies in the past but just don't remember seeing something like this, but I admit I usually don't shoot into the Sun so maybe I didn't realize this before.

Would be great if anyone can point me in the right direction.


Below are from the test roll. Smudges are on the dirty window.

The Sun right at the edge. NO issue (or at lest not visible enough)


The Sun in the frame. All shots with same framing had this boxed flare.

 

[Rob-F]

Well, that, I've never seen before. The fairly straight edges left and right suggests shutter curtain edges. The central area looks overexposed. Possibly one edge is caused by the first curtain stalling momentarily; and the other, by the second curtain behaving in a similar way, effectively giving a longer exposure in that area. And might there be a reflection off one of the curtain ends? And a screw missing from the body, admitting light? You might cover the camera with black tape to see if it goes away.

 

[splitimageview]

Maybe it's just the nature of direct sun flare with that lens. Can you put the lens on a digital of some variety and do some further test shots?

 

[santino]

Dirty window… did you shoot through a glass window? Could be the reason.

 

[coelacanth]

Rob-F,
I'm not sure if I'm seeing the exposure diff in the middle. Well, the Sun is there so it's super bright, but if you follow the Left and Right edges of that boxed flare where you don't see the lines/edges, they exposure itself looks uniform, but maybe I'm missing something. Like you said, the first thing I thought of was the shutter curtains because of the fairly straight edges.

splitimageview,
The lens is modern Elmar-M 50mm F2.8. I couldn't make this happen with the SL2-S. I don't have another film M body to test with. I've had this lens many times in the past and don't remember seeing anything like this. I tried with and without filter/hood with no meaningful differences.

santino,
Dirty window bit is (in my opinion and testing) not a part of the equation. The first two pictures were taken outdoor with nothing in between the scene and the camera.

It's been a head scratcher. I was hoping someone has seen this before, but maybe I just gotta talk to Don. Good thing is that the camera was purchased from Leica Store SF with DAG Camera's 6 months warranty. I really didn't want to be without the camera during the repair (if that's what's needed) though. Will try to determine if this is not normal or something to expect, but if anyone has seen/experienced this, please chime in.

Thanks all for your comments so far.

 

[coelacanth]

splitimageview,
I guess this could be a combination of the lens and the horizontal cloth shutter curtains so it will not manifest itself with vertical metal shutter on the SL2-S.

 

[coelacanth]

I might have found something similar:


See comments by "Andy_Shields" half way down.

I don't think the hood was the issue, but what he said later:

Check the left edge of the sun flare. Now that I'm looking at it again, it might actually be the sun reflecting off the leading edge of the second curtain.

Which may be something I was thinking above. It's basically the very strong light reflecting off of the metal edges of the curtains. His conclusion was this is something inherent, not a defect or shutter problem. I guess one can put matte paint on the metal ends of the curtains, but that's a mod at that point.

 

[Freakscene]

Flare is angle-dependant. The lenses for a Leica M project back at a quite acute angle at the edges. The edges of the shutters are not as matte as the curtains or inside of the camera. The slit in the shutter at 1/1000s is narrow. Every film Leica M I have has done this at one time or another in my experience.

 

[coelacanth]

Thank you Freakscene. Like you said, the metal edges are definitely not as matte as the the rest, and I can imagine this is causing this look in extreme condition, and I assume the lens choice can contribute to this.

 

[Rob-F]

In addition to the metal edge reflections, I see greater exposure in the central area. Possible one extra stop. So I think a complete theory should also explain why that happens.

 

[Freakscene]

In addition to the metal edge reflections, I see greater exposure in the central area. Possible one extra stop. So I think a complete theory should also explain why that happens.

The flare window is narrow because of the placement of the light source in the frame which creates a narrow flare angle in the first place. This concentrates the flare in the centre near the light source. The flare that is generated off the curtain frame edges is also directed towards the optical centre of the lens, but this additional flare is what generates the flare bleed beyond the hard line of reflection that comes directly off the frame edges.

If you get a Leica with the back open and the shutter disconnected from the drive mechanism and put the two curtains about 2.5mm apart, then put it on a tripod and move the shutter across, you can see effect projected onto paper or another surface. Just DO NOT, please, really DO NOT, whatever you do, look at the sun through the lens with the back open. You can fry your retinas.

My father put a matte finish on the shutter curtain frame edges of my M Leicas I bought while he was still young enough to do optical work, and this softened but did not remove this type of flare.

Marty

 

[EarlJam]

I got something similar about 10 years ago in a strong backlight situation, M6 TTL with either 35mm or 50mm Summicron., which I suspect was an optical issue. Since then, I've been a bit more judicious when sun is low-ish and in front of the camera. I'll typically use my left hand to shade the lens over the hood. That said, I agree with those pointing to the metal edge on the shutter curtain as a likely source for the anomaly you're seeing.