Hot pixel hell!

[pilarcg]

Help! I just got the sony A7Riii and to my horror i discovered hot pixels in all my long exposure images, frantically started reaching online and after digging around i found a solution (remap camera sensor by temporary changing the date on camera) it worked to some degree but i still have some hot pixels all over my images. I do a lot of daytime long exposures and NR in camera is not an option for me. Anyone heard of this issue before or do you know if this is with sony in general or maybe i got a bad copy? I'm regretting selling all my nikon gear.

 

[Astrophotographer 10]

Help! I just got the sony A7Riii and to my horror i discovered hot pixels in all my long exposure images, frantically started reaching online and after digging around i found a solution (remap camera sensor by temporary changing the date on camera) it worked to some degree but i still have some hot pixels all over my images. I do a lot of daytime long exposures and NR in camera is not an option for me. Anyone heard of this issue before or do you know if this is with sony in general or maybe i got a bad copy? I'm regretting selling all my nikon gear.

Can you post a sample image with all the settings you used?

Greg.

 

[pilarcg]

These are throughout the entire image.

 

[AstroDan]

Most sensors will show hot pixels after exposing for a few minutes, especially if it is warm. Take a few dark frames at the same temperature, average them, and subtract them from the image - it will clean up the hot pixels.

 

[Astrophotographer 10]

Most sensors will show hot pixels after exposing for a few minutes, especially if it is warm. Take a few dark frames at the same temperature, average them, and subtract them from the image - it will clean up the hot pixels.

Yes good advice, that should do it. The A7r2/3 is a bit noisy in the shadows in long exposures that is true.

Darks will probably clean up a lot of it but some may remain as I believe there is a random element to this noise. So some software clean up may still be required. Simply using LR noise colour noise reduction gets rid of most of it.

Greg.

 

[pilarcg]

thank you, i'll have to find out how to do that (average them, and subtract them from the image) never had problems with hot pixels to this degree with my nikon D750. It just really sucks i have to do this extra step to all my long exposures if it even works.

 

[RGBCMYK]

Is there a reason that you are not using the long exposure noise reduction? Of course creating dark frames is another choice but you will need to do one or the other. I never shot Nikon long exposures before but always had to with both Canon and Sony cameras. I did like the Canon method that allowed you to fill the buffer before the required dark frame capture.

 

[DenImage]

If you're unhappy with the camera due to a possible manufacturing fault, send it back for replacement. Simple really, so I don't see any reason for panicking.

Den

 

[No account anymore]

If in-camera long exposure noise reduction is not an option to you, just take one "dark frame" (lens cap on, same exposure as the long exposure you use for capturing the frame, taken at the same temperature), and subtract this dark frame from the image file with Photoshop. Astrophotographers have used this "dark frame" technique to remove hot pixels for tens of years.

Anoher great technique is splitting the exposure in shorter exposures, say five files, instead of one longer. When summing the image data (Photoshop > Statistics) you get the same result as one single exposure, and also smoothed out noise, better fine detail, and more than a stop added dynamic range! Really nice, insn't it?

If there is a problem, you can be sure there are very good workarounds! The camera is like it is (great, but can't do everything perfect), so just work with it, not against it.

 

[No account anymore]

If you're unhappy with the camera due to a possible manufacturing fault, send it back for replacement. Simple really, so I don't see any reason for panicking.

Why all those "advices" for returning cameras that are not faulty?

I would relly call such an action for "panicking"!

 

[pilarcg]

I don’t want to use NR in camera because I mostly do 3 minute long exposures...that will take it to 6mins! I have patience but not for that long for a single shot...

 

[pilarcg]

Thank you I’ll have to try this I guess. I know it’s not perfect but for the money this camera cost and because of the kind of photography I do (long exposures) I didn’t expect this issue to have such an impact in my work flow to try to work around this issue.

 

[DenImage]

If you're unhappy with the camera due to a possible manufacturing fault, send it back for replacement. Simple really, so I don't see any reason for panicking.

Why all those "advices" for returning cameras that are not faulty?

I would relly call such an action for "panicking"!

The OP started this thread with "Hot Pixel Hell!", and wrote in his post:

"Help! I just got the sony A7Riii and to my horror i discovered hot pixels in all my long exposure images, frantically started reaching online...I'm regretting selling all my nikon gear"

IMO, my response is reasonable.

Den

 

[Velocity of Sound]

I don't know if this makes it any better, but my understanding is that the second "noise reduction" exposure isn't actually capturing the scene, but just blackness. In other words, take your initial three-minute shot, and once it's done, you can move on and/or reposition the camera. Granted, the camera is still not usable for the next three minutes, but perhaps that makes it a bit better than feeling like the camera has to sit on the tripod for a full six minutes?

Can I offer a sort of joke response? Instead of returning your ARIII, buy a second one so that you can swap between the two and keep shooting with the ready camera while the other one is working on the noise reduction exposure

 

[pippo27]

hi,

I do a lot of daytime long exposures and NR in camera is not an option for me.

I don't know if this will be acceptable to you, but some raw converters can deal with hot/dead pixels (either with heuristic techniques or with black frame subtraction) during postprocessing, essentially automatically.

 

[dMw_Ben]

I don’t want to use NR in camera because I mostly do 3 minute long exposures...that will take it to 6mins! I have patience but not for that long for a single shot...

All the long exposure NR does is take a dark frame and subtract it from the photo you just took.

It does the same thing as if you took an extra dark photo yourself and averaged the two in lightroom later. It just does that bit for you at the time.

Use the long exposure NR, spend the 3 minutes enjoying the world around you. Breathe in, breathe out, and so on...

 

[No account anymore]

Why not first check if his results are normal for the A7rIII? Long exposure noise is not an unknown issue.

 

[DenImage]

Why not first check if his results are normal for the A7rIII? Long exposure noise is not an unknown issue.

My response was related to his panicking.

Den

 

[JimKasson]

If you're unhappy with the camera due to a possible manufacturing fault, send it back for replacement. Simple really, so I don't see any reason for panicking.

Why all those "advices" for returning cameras that are not faulty?

I would relly call such an action for "panicking"!

The OP started this thread with "Hot Pixel Hell!", and wrote in his post:

"Help! I just got the sony A7Riii and to my horror i discovered hot pixels in all my long exposure images, frantically started reaching online...I'm regretting selling all my nikon gear"

IMO, my response is reasonable.

I'm not seeing any indication that a replacement would necessarily be any better.

Jim

 

[DenImage]

If you're unhappy with the camera due to a possible manufacturing fault, send it back for replacement. Simple really, so I don't see any reason for panicking.

Why all those "advices" for returning cameras that are not faulty?

I would relly call such an action for "panicking"!

The OP started this thread with "Hot Pixel Hell!", and wrote in his post:

"Help! I just got the sony A7Riii and to my horror i discovered hot pixels in all my long exposure images, frantically started reaching online...I'm regretting selling all my nikon gear"

IMO, my response is reasonable.

I'm not seeing any indication that a replacement would necessarily be any better.

Jim

--

Maybe the replacement would have less hot pixels???

Den