This is around a 5 minute exposure of the Pier in my home town. When ever I do these long exposures I always get these hot pixels, at least thats what I think they are? Little red, blue, green and white dots all over my photo. They're extremely aggravating. I cleaned up a lot of them in this photo but I DO NOT have the patience to try and get rid of them all. Is there something I'm doing wrong that causes these? Is it just the fact that I'm shooting on a Nikon d3200 and it struggles with these types of shots? I even remembered my cap for the viewfinder this time which I usually forget. Any advice on this would be greatly appreciated and any comments on the photo would be welcomed as well. Thanks.
Kyle - I shoot Nikon as well. I don't think it is the D3200.
I reset the sensor by running the sensor cleaning function three times consecutively. I had the same issues and since I started using this little trick, the problem has been minimized.
In post you can help clean it up on PS by running the dust and scratches filter. You have to be careful not to lose detail.
Hope this helps.
Another option, Just a fast click using the software "DeNoise" (there is a 30 day trial). I did it here.. and it removed all the hot pixels. Be careful though as it added halos to your details in the bridge and horizon boarder; but easy enough to paint/mask that back in. Turns a tedious task into a rather fast one. There is other software but this one is just three sliders, nice and fast. (note: the results would of been better on the original full sized raw file)
Just a thought and option, nothing more. Hope this helps.
Hey Kyle, I can't really comment on the hot pixels issue but the picture is beautiful.
Thanks!
You can take several exposures and stack them in post. By averaging them, any dead or hot pixels should be canceled out.
This works beautifully for random noise, but hot pixels are usually constant and using a dark frame ( as suggested by Brian Jones ) will sort this out. Random noise will be eradicated by taking more than about five frames and blending them in Photoshop.
Astrophotography sites are the best place to get tuition since these hardy people may stack many frames to make one picture.
This technique may be either inappropriate or very interesting if there is movement in the photograph.
Does your camera make a “dark frame” after such a long exposure? In other words, after a five-minute exposure, does the camera close the shutter and make a second exposure for the same duration? You’d definitely know if it was doing this as it can seem like the camera is broken when it occurs. What’s happening is the camera is making a reference file with nothing but a noise signature and then comparing that to the exposed image. It then subtracts the noise from the image and makes it look a lot cleaner. Long exposures like this generate a lot of heat in the sensor and that manifests as excessive noise. Without a dark frame to compare to, the camera will just save the noisy file. This feature might be called “long exposure noise reduction” or something like that.
Yes my camera does do that however I have it turned off so I can take more photos. Maybe I should turn it back on 🤷♂️
I expect this will fix the issue. Let us know how it works out.
We’ll see. I think I’d rather try to deal with it in post than deal with the LENR. But the next time I try a long exposure like this I’ll have to turn it back on and see how much it helps.
I think you’ll be surprised at how well it works. Post processing noise removal can only look at the image noise and make an educated guess at what is noise and what is detail. When the camera compares a dark frame to your image, it is looking at the exact noise signature created by the long exposure and attempting to remove it without affecting the details of the photo.
Ugh! I need to use this advice. Way too much noise in my Milky Way shots. Thank you, Phillip.
Hey Kyle,
These are hot pixels caused by the long exposure. You can help eliminate some of this noise by turning Long Exposure NR (for noise reduction) on (this is how it is labeled on my D7200). You can expect a delay in displaying the image after the image is made while using this feature. It does not clean it up entirely, but it certainly helps.