Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Nikon makes firmware for astronauts to block cosmic rays in photos

petapixel.com

Post reply on HN
Print view View original

61–70 of 70 posts

Re: Nikon makes firmware for astronauts to block cosmic rays in photos

#61

Post by dghlsakjg »

caseyohara wrote: post #57
dghlsakjg wrote: post #50

Earlier quoted context omitted.

Yeah, but that’s like saying your mechanic shouldn’t take test drives because every mile driven shortens the life of the car. The shutter, which is replaceable, is normally rated, for 200k-1mm actuations MTBF. Even taking a reference photo every day won’t truly impact shutter life. Anecdotally: I have a 20 year old Canon 1D that is 50% over it’s rated shutter life, and that camera was used for photojournalism (used H…

Most (all?) mirrorless cameras these days have an electronic shutter too, so it's not like it would put any extra miles on the mechanical shutter.

You need to have perfect dark to take the reference image, so even on the mirrorless ones you end up having to close the mechanical shutter to get it done.

Re: Nikon makes firmware for astronauts to block cosmic rays in photos

#62

Post by mikewarot »

gsich wrote: post #60
mikewarot wrote: post #56

Earlier quoted context omitted.

The D5100 creates a new folder when it wraps.

Yes. On camera it's not an issue. The issue comes when you want to store more than 10000 pictures (or even a subset who happen to have the same numbering) in the same folder. But I already wrote that subfolders don't count. To quote Ken Rockwell: >File numbers have three programmable letters (good), but then an underscore and only 4 digits, so it only can make 10,000 shots before file names repeat. At 120 FPS it's tr…

Many file systems struggle with a large number of files in a single folder. It's a relatively new problem to have.

A few lines of python or a shell script are required to rename them on import

I can see how it is annoying, though. It is, after all, the first of the 2 biggest problems of computer science:

  Naming
  Cache invalidation
  Off by one errors

Re: Nikon makes firmware for astronauts to block cosmic rays in photos

#64

Post by gsich »

mikewarot wrote: post #62
gsich wrote: post #60

Earlier quoted context omitted.

Yes. On camera it's not an issue. The issue comes when you want to store more than 10000 pictures (or even a subset who happen to have the same numbering) in the same folder. But I already wrote that subfolders don't count. To quote Ken Rockwell: >File numbers have three programmable letters (good), but then an underscore and only 4 digits, so it only can make 10,000 shots before file names repeat. At 120 FPS it's tr…

Many file systems struggle with a large number of files in a single folder. It's a relatively new problem to have. A few lines of python or a shell script are required to rename them on import I can see how it is annoying, though. It is, after all, the first of the 2 biggest problems of computer science: Naming Cache invalidation Off by one errors

10000 is not many. It's not even a power of 2 so there is no technical reason for that number. The fact that Nikon (according to the article) is able to provide a fixed firmware is proof enough.

Re: Nikon makes firmware for astronauts to block cosmic rays in photos

#65

Post by strogonoff »

frostburg wrote: post #18
kuschku wrote: post #13

Earlier quoted context omitted.

Funny, on the FX30 it's actually exposed as a setting with a proper description. Maybe because the FX30 lacks the physical shutter, and instead relies on you putting a lens cao on? If so, I'd expect the A9iii to have the message too.

I would assume so, it's the same on my Sigma fp L.

Does fp L automatically offset raw values in DNG/CinemaDNG files in accordance with the latest dark frame, or is it only applied to JPEG output?

Re: Nikon makes firmware for astronauts to block cosmic rays in photos

#66

Post by mikewarot »

gsich wrote: post #64
mikewarot wrote: post #62

Earlier quoted context omitted.

Many file systems struggle with a large number of files in a single folder. It's a relatively new problem to have. A few lines of python or a shell script are required to rename them on import I can see how it is annoying, though. It is, after all, the first of the 2 biggest problems of computer science: Naming Cache invalidation Off by one errors

10000 is not many. It's not even a power of 2 so there is no technical reason for that number. The fact that Nikon (according to the article) is able to provide a fixed firmware is proof enough.

If you put more than 10,000 files in a single folder on a host system, you may have trouble, depending on the file system. Here's a good example of why from [1]

  This isn't really a very big deal with newer filesystems such as XFS and ext4, but on older or misconfigured filesystems it can be a serious problem.

  With older Linux filesystems such as ext3, a directory is just an unordered list of files.

  That it is unordered is important, because it means that the only way for the system to find a file in a directory is to search it from the beginning to the end.

  If a directory contains 3,000 files, it will take an average of 1,500 comparisons to find a random file in the directory. But if the directory contains 300,000 files, it will take an average of 150,000 comparisons to find a random file in that directory.

  In either case, if the directory entry is not already cached in RAM, it must be loaded from disk, which would add a significant amount of time to the file access, proportionate to the size of the directory. Obviously a small dentry can be loaded faster than a large one.

  Thus, it is much faster when you use a more hierarchical directory structure to separate large numbers of files into unique directories.
[1] https://serverfault.com/questions/736872/why-there-shouldnt-...

Re: Nikon makes firmware for astronauts to block cosmic rays in photos

#67

Post by gsich »

mikewarot wrote: post #66
gsich wrote: post #64

Earlier quoted context omitted.

10000 is not many. It's not even a power of 2 so there is no technical reason for that number. The fact that Nikon (according to the article) is able to provide a fixed firmware is proof enough.

If you put more than 10,000 files in a single folder on a host system, you may have trouble, depending on the file system. Here's a good example of why from [1] This isn't really a very big deal with newer filesystems such as XFS and ext4, but on older or misconfigured filesystems it can be a serious problem. With older Linux filesystems such as ext3, a directory is just an unordered list of files. That it is unorder…

So not a problem. See XFS and ext4 as you wrote. I don't care about legacy filesystems. Neither should Nikon. Besides, even if Nikon stores them in different folders, they could keep the numbering. Not reset it to 0. Best of all worlds.

Also, this issue could also arise even with 2 pictures you want to store in the same folder. (Although renaming is easier ofc then)

Re: Nikon makes firmware for astronauts to block cosmic rays in photos

#69

Post by frostburg »

strogonoff wrote: post #65
frostburg wrote: post #18

Earlier quoted context omitted.

I would assume so, it's the same on my Sigma fp L.

Does fp L automatically offset raw values in DNG/CinemaDNG files in accordance with the latest dark frame, or is it only applied to JPEG output?

Sorry, I only saw this question now. It does get applied to raws but I think in a non-destructive way (this is also true of Nikon cameras, if you look at the untouched, non demosaicized image you can spot the hot pixels).

Re: Nikon makes firmware for astronauts to block cosmic rays in photos

#70

Post by strogonoff »

frostburg wrote: post #69
strogonoff wrote: post #65

Earlier quoted context omitted.

Does fp L automatically offset raw values in DNG/CinemaDNG files in accordance with the latest dark frame, or is it only applied to JPEG output?

Sorry, I only saw this question now. It does get applied to raws but I think in a non-destructive way (this is also true of Nikon cameras, if you look at the untouched, non demosaicized image you can spot the hot pixels).

Thanks for the info.

I think if you can see hot pixels when looking at the raw before demosaicing then the dark frame is not applied (which makes sense, since a DNG is supposed to be more or less a sensor snapshot).

If you do not see them after you processed the raw, I think that would just be your software filtering outliers as best it can, since it would have no way of knowing about the dark frame. I doubt it embeds the dark frame in every DNG, would take up extra space and I am not sure the format even supports that, so likely it just keeps the latest dark frame in memory and applies as part of internal pipeline.

Post reply on HN