[HN Gopher] Nikon makes firmware for astronauts to block cosmic ...
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Nikon makes firmware for astronauts to block cosmic rays in photos
Author : isaacfrond
Score : 110 points
Date : 2023-12-08 10:31 UTC (1 days ago)
(HTM) web link (petapixel.com)
(TXT) w3m dump (petapixel.com)
| photoGrant wrote:
| digital cameras carried on planes in the early days had cosmic
| ray issues too. So they sent them by boat. Hell. The ones today
| do. This is a weird article though. A lot of cameras compensate
| for dead pixels and cosmic rays.
|
| It should also have been designed in every camera to have unique
| file names. It's ridiculous they all don't.
| sudosysgen wrote:
| If you use a Sony A7 series camera, every month, the camera
| will take a picture upon shutting it off, which it uses to
| remove dead pixels/hot pixels - you can hear it, actually.
|
| If ever you have a pixel die or get stuck, you can also
| manually set the date a couple months ahead and turn it off -
| it will most likely be fixed when it turns back on.
| mschuster91 wrote:
| > If you use a Sony A7 series camera, every month, the camera
| will take a picture upon shutting it off
|
| So THAT is that mysterious click-clack of the shutter that
| randomly appears on my A7S2. I've been putting off sending it
| in for repair, but now I can completely avoid that. Many
| thanks!
|
| Do you happen to have a link to some documentation for it?
| sudosysgen wrote:
| As far as I know, there's no official documentation for it,
| but people noticed that it happened every month and that it
| would fix dead pixels (for example:
| https://www.4kshooters.net/2015/12/01/an-easy-trick-to-
| fix-d...)
|
| I personally used this trick twice to fix dead pixels on my
| camera, so I can attest to that.
|
| For cameras without a mechanical shutter, there is instead
| an option to do it in the menu, for example : (https://help
| guide.sony.net/ilc/2010/v1/en/contents/TP0003229...)
| kuschku wrote:
| 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.
| frostburg wrote:
| I would assume so, it's the same on my Sigma fp L.
| photoGrant wrote:
| A manual sensor clean in most cameras does this. If
| mirrorless, leave the cap on
| KennyBlanken wrote:
| Many cameras have a menu option to trigger a dark frame
| calibration. Been a thing for a long, long time.
| hef19898 wrote:
| I can do it on my Nikon D700, so yeah, quite an old
| feature. Very usefull so!
| xattt wrote:
| I trump you with my Canon 30D that also had this feature.
| sudosysgen wrote:
| It's not about dust on the sensor, it's actually software
| that maps dead pixels to fill them in every time you take a
| picture (as well as dark frame offsetting, presumably)
| photoGrant wrote:
| Again... the manual sensor clean action action does both.
| Granted I mean the manual 'automatic'
| sudosysgen wrote:
| Ah okay, I was confused on what you meant by manual
| sensor cleaning, to me that means (on a DSLR also locking
| the mirror up) and swabbing out the dust.
|
| On a Sony E-mount camera, the ultrasonic sensor cleaning
| doesn't do pixel remapping, only the date trick (or the
| menu option on electronic shutter models) works to
| trigger it manually.
| lakpan wrote:
| So, wait. The camera can fix dead pixels but only does so
| once a month? Dead pixels are dead easy to detect by the
| sensor, why don't they do it immediately? Way to ruin a bunch
| of photos between cleanups...
| yakubin wrote:
| Every photo taken shortens the life of a sensor.
| riversflow wrote:
| To add to this, with those particular cameras(it's the
| frame I shoot on), you're encouraged by the form factor
| and ergonomics to turn them off when idle to get the most
| out of the smallish battery, they boot in like 1s. A
| battery is good for ~350 shutter pulls, I don't want to
| use one of those every time I think about taking a
| picture.
|
| Also, a dead pixel is not a ruined photo, it's a minor
| inconvenience in editing at worst. And every photo I take
| on a FF is getting edited, the gorgeous RAW output is
| what I'm there for.
| sudosysgen wrote:
| That's not really true, it's only a problem for the
| shutter. The sensor doesn't really break.
| yakubin wrote:
| You're right. I misremembered. The term is "shutter
| life". Same result though.
| wtallis wrote:
| Not the same result: we're talking about taking a picture
| _without_ opening the shutter.
| yakubin wrote:
| Given that shutter sounds are produced, I'd guess the
| shutter is opened[1]:
|
| _> During this time, shutter sounds will be produced._
|
| [1]: <https://helpguide.sony.net/ilc/2010/v1/en/contents/
| TP0003229...>
| dghlsakjg wrote:
| The shutter is actually being closed. On mirrorless
| cameras the shutter is by default open so that viewfinder
| framing can be accomplished, then it quickly closes,
| opens for the photo, and ends closed before opening again
| to act as a viewfinder.
|
| In the case of a reference photo it is closing, not
| opening, taking a read of the sensor, then opening again.
| gruez wrote:
| Do mirrorless cameras even have physical shutters? Or is
| it all digital?
| yakubin wrote:
| Most do. Some, like Nikon Z8 and Z9, don't.
| sudosysgen wrote:
| Older ones do, because the readout speed of sensors was
| not fast enough. Cameras with stacked or global shutters
| generally don't, because it's no longer an advantage. In
| between, it's a choice you can make whether or not to use
| the shutter.
| dghlsakjg wrote:
| 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 HARD) for most of its life.
| sudosysgen wrote:
| Sometime dead pixels are not a fully on-off affair, so
| taking a dark frame is really needed, and you don't want to
| be doing that too often because then the camera is not
| usable then.
|
| It sucks, but it is what it is, and it's not too difficult
| to batch remove dead pixels - if you even notice them.
| yakubin wrote:
| Does it affect RAW photos or only JPEGs?
| sudosysgen wrote:
| It affects RAW photos, too. You also have similar artifacts
| sometime from on-sensor phase detection pixels.
| CarVac wrote:
| It's just them performing dark frame subtraction at short
| shutter speeds too, not just long ones.
| somemirth wrote:
| It's a poorly written and badly explained article. The first
| comment does a great job of explaining why, and how the new
| "firmware" actually works
| Pixie_Dust wrote:
| > It's a poorly written and badly explained article ..
|
| And the title is erroneous. The firmware used the noise
| reduction circuits to disguise the effects of cosmic rays on
| the sensor.
| jakeinspace wrote:
| Hey, us embedded programmers never get credit. It's nice once
| in a while to steal some from EEs.
| KennyBlanken wrote:
| The noise reduction they're referring to is dark frame
| subtraction used for thermal noise and defective hot pixel
| removal (the latter is what the ISS has to worry about.) Numerous
| cameras from other companies allow for forcing that on at any
| speed via menu options, not just slower shutter speeds.
|
| I had this feature available on an early 2010's Olympus. They
| called it "Noise Reduction" (not "noise filter", that's
| different) and it could be set to off, normal, or "on." On makes
| it behave like this "special" Nikon firmware, always performing
| the dark frame subtraction. "Normal" applies some logic based on
| shutter speed and ISO, and off turns it off completely. Manual
| dark-frame calibration was also available via the menus.
|
| I'm not sure why Nikon is tooting their horn so loudly about
| adding (only for people in the ISS) what's been available to
| earthbound users of other camera systems via a menu item for a
| decade?
| hef19898 wrote:
| I guess the difference is some better algorithms to identify
| cosmic ray issues and the like, as oppossed to simple noise
| reduction.
| wdfx wrote:
| Exactly - if you think about the automatic dead/hot pixel
| removal, the camera is going to assume these errors are
| always in the same location on the image, and maintain a
| mapping of where they are.
|
| If instead in space these errors are caused by cosmic rays
| and can affect any part of the image randomly, and for a
| limited time only, then this requires a different algorithm,
| otherwise the camera will eventually be painting out the
| entire image as different areas get affected.
|
| That all said, I know nothing of the details of these camera
| firmwares, and they may be doing other things instead. But, I
| suspect it is not as simple as some comments in this thread
| suggest... because nothing ever is.
| malfist wrote:
| Dark frame subtraction cannot remove cosmic rays. It removes
| things the camera sees in the dark at the time of dark frame
| capture.
|
| This is things like dead pixels, hot pixels and amp glow.
|
| If a cosmic ray was removed by a dark frame, two cosmic rays
| would have had to happen, one during dark frame and one during
| the actual capture. They'd have had to be the same intensity
| and hit the same pixels. This is probably never going to
| happen.
|
| As for who this is for? You and I may benefit too with less
| cosmic ray noise in our photos. We still see them, though we
| have a lot more information in our photos. You can see them too
| if you take dark frames yourself. Even if you put your camera
| in the freezer to avoid most other noises you'll see them
| davidmurdoch wrote:
| What's the freezer thing about?
| dekhn wrote:
| there are several sources of pixel noise, some of which are
| temperature dependent. Making the sensor cold reduces the
| temperature-dependent pixel noise background.
| davidmurdoch wrote:
| So less sensor noise, but all your lenses are foggy now.
| Haha
| malfist wrote:
| Well, for dark frames the lense cap is on. The idea is
| that you're taking a totally black photo.
|
| Freezer, along with being cold is also a big metal box
| that will help deflect some rays
| causi wrote:
| I wish there was good software for hot pixel removal in normal
| digital cameras. Sure you can photoshop pictures one by one, but
| if you have the same set of bad pixels on every shot and need to
| remove them in batches? Nothing will do that as far as I know.
| lm28469 wrote:
| I'm pretty sure you can do that in photoshop batch actions for
| a good 15 years
| terramex wrote:
| I once used astrophotography tool DeepSkyStacker for that.
|
| Loaded all my photos as light frames, prepared and loaded a
| dark frame, turned off alignement, post-processing etc and
| turned on "Create a calibrated file for each light frame". It
| subtracted given dark frame from every photo and exported them
| to 16-bit TIFFs.
|
| It can be used from command line if you want to automate it
| more or make custom GUI. Windows only unfortunately, but it is
| open source.
| sudosysgen wrote:
| If you use Lightroom, make a 1 pixel patch around the hot
| pixels, and then copy/paste the edits. Basically every other
| image editing software is also going to allow a similar
| workflow.
| gsich wrote:
| Nikon should fix file numbering in general.
| mikewarot wrote:
| The file numbering system is unique enough that you're not
| going to have the same file and folder name together, and you
| can set the prefix, iirc.
|
| My photos are in /photos/yyyy/yyyymmdd/nikon1xx/dscnxxxx.jpg
| and I've been using this system since 1997
| ISL wrote:
| I wish every manufacturer had an option for unique, nonrepeating,
| filenames!
| COGlory wrote:
| We do a very similar thing for X-Ray rejection from electron
| microscope cameras.
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