Uneven exposure bands, top exposed properly rest underexposed

[Guest]

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Ralph,

 

I see three distinct area in the sky ... extending upwards from the near hills on the horizon ...1)distant line of hills? 2)atmospheric dust and clouds and 3)a cloud layer that becomes clear sky ... each with a different Ev. From darker to lighter as you go up. I do see banding in the middle layer ...

 

But all three layers are evident in the correctly exposed last picture on the right in post #12. Why they are exaggerated to this extent is beyond me ...

 

Obviously I must be missing something.

 

Bob

[ralphh]

There are no cloud layers - just hills then graduated sky. those layers in the sky are the issue were discussing - they're not mean to be there!

 

There appear in the pic in #12 cause it's the same photo pushed 2.5 stops

[Adam]

I have seen all kinds of effects, but the chances are slim - I don't really doubt it's a shutter issue, but worth making a few simple checks, esp as you hard other card issues that day

 

Another test for you. If it is a card / firmware fart it'll be pixel based, as where even at f16 the edge of the shutter blade will be soft.

 

Look at it at 100%. If exposure change has a razor sharp, one pixel to the next edge it's a data issue. If it's slightly feathered it's a shutter issue.

Thanks! I agree. I looked at the transitions. They are smooth. Here is a crop. I am going to switch cards and see. But I have not experienced the problem yet.

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[Adam]

Hi Adam,

I'm sorry to hear about this.

 

I suppose I'm somewhat preconditioned to lean towards shutter issues. That aside, the shutter runs vertically (I believe) so the banding in the image would be consistent with a shutter having variable speed.

 

It could be electronic, but i doubt the SD card is at fault. I would save the image on the current card as evidence (you may need it later) and change over to a different card.

 

With the shutter being the prime suspect, I would hit it with continuous operation at different shutter speeds to see whether normal operation occurs on every shot. Since I don't use LV, I have no idea whether continuous is possible in this mode, if it is I would 'hit' it here too.

 

You probably know this already, but just in case it's worth knowing that the camera keeps an error log within its internal memory, so on return (if it comes to this) Leica will be able to interrogate the log and diagnose the fault, if it is a camera issue.

 

You mention the SD card has been reliable for over a year, so I'm guessing the camera is of a similar age. Anyway 16-20k clicks should be nothing for a robust M240.

Hi Steve,

 

Thanks! I am glad your issue has been resolved. I wish you lots of enjoyment with the new camera.

 

I  also doubt that it is a card issue. One of the shots has a very tilted horizon, but the bands are parallel with the frame. That made me immediately suspect the shutter.  But it is good to check and eliminate other possibilities.  I have used the continuous mode to the max quite often (it is an M-P). Never had any problems. This was actually non continuous shooting with a tripod.  The camera is barely a year old. It had the sensor replaced already (I never found out why - I just sent it to have the sensor cleaned), but other than that it has been working great.

 

If it is the shutter, this is by no means normal wear and tear, but rather a serious malfunction. One immediate effect, I now chimp all my shots.

 

I did not know about the internal log. That is good to know. I will be contacting Leica once I return home.

[Adam]

LV may be the culprit.  Does it happen when that's off?

 

Shouldn't happen regardless - but may point to a solution.  Perhaps can be fixed in firmware

Thanks. It only happened with the EVF and thus LV. I have shot lots of time in continuous mode thus taxing the shutter but primarily without LV. The shutter never malfunctioned. I suspect it is very possible that  LV played a role here and exacerbated whatever the problem is with my camera.

 

But I would not count on any new firmware, unless it turns out to be a major flaw.

[Adam]

Adam,

 

I am bit confused .... nothing new with that state .... but in your original post exposures were 12 to 15 seconds ... in the latter post 1/12 to 1/15.

 

Are these two different times of day?

 

Consider that classic CW metering with a 75 is pretty much a large area as 1/3 of the image covers a good portion of the transition from dark cloud bank 

and distant hills to the much brighter sky.

 

If the proportion of sky to lower area increases with CW metering then the chance of underexposure is dramatically increased. So spot metering 

would allow for a better exposure.

 

The banding to me looks normal sensor related due to underexposure ... 

 

If the exposure times were on the order of 12 seconds the relative open to close time compared to the total time open would be

so small that I doubt it would show as dramatically as it appears here even if it were stepping. Hard to imagine that from 1/12 to 1/15

of a second would require 2.55 stops in post. So at these shutter speeds looks like the values are wrong.

 

The dynamic range of your scene is huge ... without a graduated filter or multiple exposures rendering it without underexposed foreground or

overexposed sky would be difficult.

 

Sorry for the run-on ... it is confusing at best.

 

Bob

 

Hi Bob,

 

The confusion is my fault. I was tired when responding.  The exposures were 1/12 and 1/15,  it was dusk around 8 pm. The two messed up images were taken within 3 minutes. The comparison image, the one that is fine, was taken 3 seconds after the messed up one.

 

The images have a big dynamic range. But the banding, especially on the shot with the tilted horizon is not consistent with the image. If it were an issue of exposure, it should be parallel to the horizon and not to the frame. Also, all my other images, over a hundred, were fine. If the camera had problems with the metering conditions this should have happened more frequently.

 

The 2.55 processing was on the messed up image to see the noise pattern. The control image was not processed at all. In other words, in the messed up image, the camera underexposed everything but the very top by 2.5 stops. The top of the image was however exposed the same as in the control image that was taken 3 sec later. 

 

Thanks for making me clarify this!

[Adam]

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Ralph,

 

I see three distinct area in the sky ... extending upwards from the near hills on the horizon ...1)distant line of hills? 2)atmospheric dust and clouds and 3)a cloud layer that becomes clear sky ... each with a different Ev. From darker to lighter as you go up. I do see banding in the middle layer ...

 

But all three layers are evident in the correctly exposed last picture on the right in post #12. Why they are exaggerated to this extent is beyond me ...

 

Obviously I must be missing something.

 

Bob

 

Hi Bob,

 

Here is a set messed up vs control. In both cases the images were taken seconds apart. slightly different angles but still.

The second ones are the messed up ones with banding and odd under or over exposure of the rest.

 

BTW this is low tide on Cape Cod, what looks like mountains are dunes and clouds. Also focus is off on the second shot, but that was probably me.

 

I should have done this comparison from the get-go. I hope this makes the issue clearer.

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[ralphh]

Thanks fir the 100% crop.  It certainly looks like a shutter issue then - it's not a card issue

 

I was going to ask if it was extremely cold, but given the location, I suspect not.

[Guest]

Looking at the crops and with the shutter times at 1/12 to 1/15 I agree that it should be an erratic shutter ... why only 2 out of 140 

is perplexing unless it is just the beginning of a problem.

 

I do hope you have another body to use as it will probably enter the black hole known as Solm repair ... for a number of months at

least.

 

Beautiful area and if you have 100+ good photographs well worth the trip.

 

 

Bob

[jdlaing]

Looking at the crops and with the shutter times at 1/12 to 1/15 I agree that it should be an erratic shutter ... why only 2 out of 140 

is perplexing unless it is just the beginning of a problem.

 

I do hope you have another body to use as it will probably enter the black hole known as Solm repair ... for a number of months at

least.

 

Beautiful area and if you have 100+ good photographs well worth the trip.

 

 

Bob

If he sends it to Solms it will definitely go into a black hole. Solms doesn't repair cameras. :-)

[sblutter]

I'm thinking shutter bounce

[Adam]

I'm thinking shutter bounce

I never heard of shutter bounce, is it literally that?

[Guest]

If he sends it to Solms it will definitely go into a black hole. Solms doesn't repair cameras. :-)

 

Sounds like Wetzler is not that much better at times ....

 

 

Bob