Vertical line in Leica M8?

[luele]

Advertisement (gone after registration)

Meaning it's risky to take these cameras on an airplane??? I can't imagine spending that much money on a camera and not take it on vacations. In fact, the only reason I got an M8 was because I hated lugging a DSLR and voluminous lenses on airplane travel.

 

Hi,

 

I had the problem several times an had written in the german forum to this subject. The first time CS told me, that this could happen during intercontinental flights because of the rays. But I had never been flying with the M8, The second time the white line problem appeared (still not flying - and not living on a high mountain - and no I am not Homer working in a atomic plant) they say it could happen because one of the 10 mio. pixels can stop working.

 

This week my M8 was at the CS because of other stripes at high isos. They changed the board (garantee) - let's have a look

 

 

luele

[Advertisement]

The Leica Q3 is available for pre-order at B&H Photo Video and Adorama

[jaapv]

There is a warning about sensor damage in both the M8 and M9 manuals. (M8 Page 125, M9 Page 165)

 

It is more of a disclaimer than a warning. However, if you are a frequent transpolar flyer you might consider an M7 and film. After all, the lymphoma, breast cancer and melanoma incidence amongst flying personell on that route is above average too, for the same reason.

 

Radiation Exposure During Commercial Airline Flights

http://ashsd.afacwa.org/docs/radbroch1.pdf

 

 

Btw, Bocaburger, it is no complete remedy to bring a DSLR, they have sensors too.....;)Although - CMos sensors, even non radiation hardened ones, like we use in our camera are certainly more resistant than CCD chips.

http://en.wikipedia.org/wiki/Radiation_hardening

[Bert N]

There is a warning about sensor damage in both the M8 and M9 manuals. (M8 Page 125, M9 Page 165)

 

They're being way too cautious here. Cosmic rays generally do not cause permanent damage in a CCD. In fact, they are sometimes used to test the performance of a CCD, in this case, to measure the CTE or charge transfer efficiency

[jaapv]

I doubt that, Bernd, given the number of vertical lines/ dead pixels reported on older M8s. Reading the article, they use the "handy defects" caused by cosmic ray strikes for measurements in that experiment. That rather proves the prevalence of such defects.

 

The charge from a cosmic hit is usually spread over more than one pixel, which makes them hard to use for a quantitative CTE analysis. This CCD has a defect that comes in very handy: Warm pixels that reach different levels in a dark exposure depending on the individual pixel and integration time. By examining the profile of warm pixels, as shown in figure , the CTE can be determined. One method would be to compare the total number of counts in the warm pixel and it's tail to the counts in the central peak. From this ratio, and the Y-coordinate of the pixel, CTE can be calculated.

[bocaburger]

It is more of a disclaimer than a warning. However, if you are a frequent transpolar flyer you might consider an M7 and film.

 

So only transpolar is deleterious? What about transcontinental or transoceanic? Even if I hadn't ever taken my M8 on a plane myself, its sensor made one long flight from the point of manufacture to Solms, and then after assembly, from Solms to New Jersey, then a flight from New Jersey to Popflash in California, and then from Tony Rose back across the country to my office. That's 4 multi-hour flights >30,000ft, and all in the cargo hold. I think I'm not alone in that my M8 racked up enough frequent flyer miles for a free 1st-class upgrade even before I opened the box, and yet knock wood I can't see any evidence of damage after numerous more flights and 3 years of use.

 

Btw, Bocaburger, it is no complete remedy to bring a DSLR, they have sensors too.....;)Although - CMos sensors, even non radiation hardened ones, like we use in our camera are certainly more resistant than CCD chips.

Radiation hardening - Wikipedia, the free encyclopedia

 

That's interesting about the CMOS vs CCD. I was only thinking about the price differential between what my DSLR cost vs the M8, in terms of the effect on my bloodpressure if one or the other became a paperweight due to cosmic radiation.

[Bert N]

I doubt that, Bernd, given the number of vertical lines/ dead pixels reported on older M8s. Reading the article, they use the "handy defects" caused by cosmic ray strikes for measurements in that experiment. That rather proves the prevalence of such defects.

 

Cosmic rays actually never interact with the sensor. They generate clouds of energetic particles when they hit air molecules 15 km above the earth. In the referenced article the cosmic ray generated charge is merely used as a source of charge for CTE measurement. Nowhere is it implied that the defects are caused by cosmic rays which can also be used to fight against terrorism...

[jaapv]

Advertisement (gone after registration)

Bottollier-Depois JF et al. Assessing exposure to cosmic radiation during long-haul flights. Radiat Res 153(5 Pt. 1):526-32; 2000.

• The lowest dose rate measured was 0.3 mrem per hour during a Paris-Buenos Aires flight.
  
• The highest rates were 0.66 mrem per hour during a Paris-Tokyo flight and 0.97 mrem per hour on the Concorde in 1996-1997.
  
• The corresponding annual effective dose, based on 700 hours of flight for subsonic aircraft and 300 hours for the Concorde, can be estimated at between 200 mrem for the least exposed routes and 500 mrem for the more exposed
  

[bocaburger]

Ok, but how many mrem does it take to fry an M8's CCD? BTW is there something peculiar about the M8's sensor that a single dead pixel produces a line? I've had dead pixels before on other cameras but they only produced a dot...much easier to deal with in post. One such camera was the Epson R-D1, which unless I'm mistaken, has a CCD not CMOS. And, it has a pixel-mapping utility in the firmware (haven't seen that on any other camera, but seems to me it should be standard equipment on every one).

[Guest mc_k]

Ok, but how many mrem does it take to fry an M8's CCD? BTW is there something peculiar about the M8's sensor that a single dead pixel produces a line? I've had dead pixels before on other cameras but they only produced a dot...much easier to deal with in post. One such camera was the Epson R-D1, which unless I'm mistaken, has a CCD not CMOS. And, it has a pixel-mapping utility in the firmware (haven't seen that on any other camera, but seems to me it should be standard equipment on every one).

 

yes, R-D1 has CCD

[adan]

So only transpolar is deleterious?

 

The Earth's magnetic field has a tendency to deflect solar wind particles into the polar areas - which is why we have "NORTHERN Lights (Aurora Borealis/Australis)" rather than "Equatorial lights".

 

File:Structure of the magnetosphere.svg - Wikipedia, the free encyclopedia

 

Also, polar flights are by definition longer flights (in distance and time), since a route over the pole is only an efficient route when between points very widely separated.

 

http://www.beloblog.com/KGW_Blogs/travel/archives/PDX%20Routes%201-07.gif

 

So, more time spent in the stratosphere, through a region with an additional dose of high-energy solar particles.