MM sensor or lens phenomena?

[Magnus_L_Andersson]

Advertisement (gone after registration)

Friends,

 

My MM has been in Germany for sensor cleaning three times since I recieved it as one of the first batches, but this is a posting addressing another topic related to sensor and/or lens phenomena.

 

The image 20141229-M Monochrom-1003998-unprocessed is a small crop of an image of the sky with gray clouds, taken with 35 Lux ASPH @ f/16, ISO 320. Circled in red you may see tendencies of dust spots, but the blue area does not reveal anything noticable.

 

If we now push the envolope a bit by using Nik Software (Color Efex Pro - detail extraction, high key) to extract details in this image we get the one in 20141229-M Monochrom-1003998-detailed. Now we find more spots than noticable in the unprocessed image, but more interestingly the blue area has been filled with a darker circular phenomena. Some further features are that increasing the aperture blurs the area in a similar way as the spots, and it is not due to phenomena in the sky since it reamains in other images. However, if I use another lens (90/4 Macro Elmar) this circular pattern is "replaced" by similar ones in other positions. Moreover, looking back at earlier sensor tests some of these patterns have been there all the time (even after sensor and lens cleaning), but some seem to be new and others to disappear.

 

Now we come to my question if this is a sensor and/or lens phenomena?

 

Regards,

 

Magnus Andersson

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

[wattsy]

The larger "blue" phenomenon is, I believe, lens related. Jimmy Hughes at Leica UK noticed something very similar when he was cleaning my Monochrom sensor and using my 35 Summilux FLE to inspect the sensor. Intrigued by it, he took further shots after loosening the lens in the mount and moving the lens slightly which resulted in the shadowy 'mark' changing position on the sensor. I can't remember exactly what Jimmy thought might be causing it but I think he felt it was the magnified shadow of dust in the lens or something like that.

 

Incidentally, the scratch-like line seen in the upper left is a sensor defect which has necessitated replacement in Wetzlar. One day next year I might get my camera back.

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

[Magnus_L_Andersson]

Dust/oil/corrosion on the sensors or in/on lenses end up as "defects" in our images.

 

Is this the price to be paid when pushing the technology, and it reminds me of one of the "problems" with Flextight scanner and a resolving power higher than the grains in the negatives.

 

Are we too picky and in demand of Utopia?

 

/magnus

[250swb]

Are we too picky and in demand of Utopia?

 

I'd expect somebody who was 'picky' to clean their sensor as soon as they see any dust appearing in the image. If it's important it needs doing, if not and you can make do without the camera again send it off. Being a place where people have everything done for them and can't do anything for themselves I think you have already found Utopia if Leica are still happy to clean your sensor.

 

 

 

Steve

[wattsy]

I don't think it is being picky or asking too much to have a sensor free of "corrosion" or other uncleanable surface defects. Dust and oil are a different matter altogether and I think it is disingenuous to lump them all together.