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Blotches on M sensor?


cossak

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please pardon for the re-post!  i could not find the original post on the thread...

 

i purchased a used M body last week - and only today made first tests with open sky as the sun finally peeked out.  

 

i see two large blotches in the (overly) saturated blue sky!  i am traumatised by my experience with the monochrom and the replacement of the sensor which took 14 months (luckily i was offered a loaner by Leica USA).  

 

have others seen anything similar to this using the M 240?    i appreciate the help in advance...

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Looks like a big dust splotch on the sensor. It might need nothing more than some gentle blowing with something like a rocket blower.  Or you can send it it for a full CLA (clean/lubricate/adjust) which might be a good idea for a used camera.

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Shoot the sky with narrowest of aperture and you should be able to see where dust is. Then you can decide whether to clean the sensor or not. Note that dust on the sensor is common and one has to learn how to deal with it. Either by cleaning (self or by professional) or by editing the picture (clone feature in Lightroom). Your dust patch looks big but easily fixable by cloning in post processing since it is in a texture less area. You would not have noticed it if there had been texture around it (like tree branches).

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please pardon for the re-post!  i could not find the original post on the thread...

 

i purchased a used M body last week - and only today made first tests with open sky as the sun finally peeked out.  

 

i see two large blotches in the (overly) saturated blue sky!  i am traumatised by my experience with the monochrom and the replacement of the sensor which took 14 months (luckily i was offered a loaner by Leica USA).  

 

have others seen anything similar to this using the M 240?    i appreciate the help in advance...

It's dirt, I often have those on my 246

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thank you all for your responses...

 

 

i am a 34 year user of M cameras...but have made the switch to digital only a few years back,  so my diagnostic abilities are not as strong as i would like.  

 

but these blemishes don't look like dust to me,  unfortunately the do look identical to the oil spotches that were on the Monochrom before it went for a sensor change...

 

i will be much relieved if the collective decision is only dust on the sensor!   

 

here is a  crop of the original image darkened to increase visibility.

 

 

i know that i can use the clone tool, use the K brush in Camera Raw etc - but one shouldn't have to, right? 

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It's dirt, I often have those on my 246

ok then...

 

what i still don't understand is why i see obvious dust specks with sharp edges,  while these large blotches are blurred...almost like foreign material on a negative would appear through the enlarger on a print - as a large discoloration with soft edges...

 

your assuredness is giving me confidence though! 

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suspect oil...

first use blower and if it it still there (highly likely as I think it is oil), then WET cleaning with Eclipse is your next step.

Avoid arctic brush as it will just smear the oil.

Albert  :)  :)  :)

If you are unsure of your technique re wet cleaning, bring it in and have a pro do it and teach you how to do it in the future.. It is not that hard but takes some supervised training...

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thank you all for your responses...

 

 

i am a 34 year user of M cameras...but have made the switch to digital only a few years back,  so my diagnostic abilities are not as strong as i would like.  

 

but these blemishes don't look like dust to me,  unfortunately the do look identical to the oil spotches that were on the Monochrom before it went for a sensor change...

 

i will be much relieved if the collective decision is only dust on the sensor!   

 

here is a  crop of the original image darkened to increase visibility.

 

 

i know that i can use the clone tool, use the K brush in Camera Raw etc - but one shouldn't have to, right? 

First you have to figure out whether it is a dust or a blotch. With narrow aperture (like f/16 or 22) the dust will be visible as a sharp object. If you still see a smeared blotch then it means it is spread over a larger area of the sensor and is not a dust. In that case blower won't work and some kind of wet cleaning may be required.

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I've never seen dust as sharp as the black dot left of centre near the top. My sensor dust is like the two blotches but much smaller.

It depends on the aperture used. I can shoot at f/1.4 or f/2 with a very dirty sensor and not see anything since dust becomes fuzzy. But the dust becomes visible and sharper with narrowing aperture. It is also a function of focal length. It is more easily visible in longer lens (at equivalent f stop).

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Perhaps its obvious, but as you are relatively new to digital, it's probably worth mentioning that such things are quite easily dealt with in post with LR.  Was actually just working on a shot that had a similar problem...

 

 

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Thank you everybody...i've just done my first wet cleaning of the sensor using the copper hill method (which unfortunately no longer exists evidently...) after a bit of effort,  and also using a sensor loupe - i was able to nearly clean the sensor...amen!   

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