Best ways to reduce noise from photos taken with old DSLR models?

[RJDG14]

I bought a Canon EOS 20D the other day since I wanted to see what DSLRs were like in the early-mid 2000s, and it's a pretty good digital camera for 2004, but unlike DSLRs from the past 10 years, I've noticed that grain in the shadows of RAW files when they are raised is very obvious even at ISO 100. You can easily eliminate colour grain, which makes grainy raised shadows a little more viewable, but the monochrome base grain is still there, and most noise reduction tools to remove the base grain sacrifice image sharpness and I feel my images look better detailed but grainy than grain-free but blurry. I'd have overall said that its sensor performs grain-wise about where good quality 35mm film at the equivalent ISO would have performed, which is below where modern DSLRs perform.

One method I have read that is supposedly good for reducing noise would be to take a burst of 5 or 6 photos and then stack them. While this technique almost certainly does work, it's not much good without a tripod, which makes me ask if there are any techniques that can greatly reduce the noise produced by old DSLRs without sacrificing image detail? The best notable technique on cameras such as the 20D that I can think of would be to shoot photos at an ISO stop above the ideal exposure, making them a little overexposed, and then digitally reducing the brightness of the RAW file by one stop, which makes shadows in the photo less grainy than they would have been had it been taken at the ideal out of the camera ISO - my 20D is pretty good at recovering highlights but performs poorly by modern standards with shadows.

Here's what a photo taken on my 20D at ISO 400 looks like if raised by 4 stops without any further editing or noise reduction:

 

[D Cox]

I use the program Neat Image to reduce noise on older images, and it works well. I hear good things about DXO's noise reduction software too.

If the photos are not as sharp as you would like, try Topaz Sharpen in Softness mode. It seems to manage to sharpen edges without adding halos -- unlike the sharpening routines in the JPG engines of cameras.

Here's a result from Neat Image.







Don Cox

 

[OrigamiCactus]

One method I have read that is supposedly good for reducing noise would be to take a burst of 5 or 6 photos and then stack them. While this technique almost certainly does work, it's not much good without a tripod,

Why? It still works really fine without a tripod, just that it works on static subjects with out fast enough burst speed.

which makes me ask if there are any techniques that can greatly reduce the noise produced by old DSLRs without sacrificing image detail? The best notable technique on cameras such as the 20D that I can think of would be to shoot photos at an ISO stop above the ideal exposure, making them a little overexposed, and then digitally reducing the brightness of the RAW file by one stop, which makes shadows in the photo less grainy than they would have been had it been taken at the ideal out of the camera ISO - my 20D is pretty good at recovering highlights but performs poorly by modern standards with shadows.

I would say that if you don't want to shoot burst, or not use any of the AI based noise reduction softwares, then overexposing is your best bet.

But the photo you posted is imo very artful, really gives an old DSLR feel to the photo.

 

[RJDG14]

I like the way photos taken at night look kind of gritty on my 20D - on my newer DSLR they don't have the same vibe to them.

 

[sybersitizen]

... most noise reduction tools to remove the base grain sacrifice image sharpness and I feel my images look better detailed but grainy than grain-free but blurry.

Have you tried the latest NR tools? They work very well at retaining detail. You might find a happy medium between too much noise and unacceptable detail loss.

One method I have read that is supposedly good for reducing noise would be to take a burst of 5 or 6 photos and then stack them. While this technique almost certainly does work, it's not much good without a tripod ...

Most stacking tools can autoalign images as part of the process.

The best notable technique on cameras such as the 20D that I can think of would be to shoot photos at an ISO stop above the ideal exposure, making them a little overexposed, and then digitally reducing the brightness of the RAW file by one stop, which makes shadows in the photo less grainy than they would have been had it been taken at the ideal out of the camera ISO - my 20D is pretty good at recovering highlights but performs poorly by modern standards with shadows.

As you acknowledge, that method risks blowing highlights. But it can work okay with some scenes.

 

[J A C S]

DXO Photo Lab has an amazing NR.

Do not raise the shadows in your old Canon shots unless you absolutely have to.

 

[RJDG14]

It's fine to slightly overexpose highlights, but not by the amount that they get overblown. You can generally overexpose them on the 20D by about 1-2 stops without them becoming overblown.

 

[RJDG14]

I've been trying to install the trial version but their trial signup form keeps immediately telling me that both my email addresses are "invalid" due to a likely Javascript bug (they are both valid), and won't let me proceed. I've contacted DXO about this issue and hopefully it can be resolved.

 

[Horacecoker]

I bought a Canon EOS 20D the other day since I wanted to see what DSLRs were like in the early-mid 2000s, and it's a pretty good digital camera for 2004, but unlike DSLRs from the past 10 years, I've noticed that grain in the shadows of RAW files when they are raised is very obvious even at ISO 100. You can easily eliminate colour grain, which makes grainy raised shadows a little more viewable, but the monochrome base grain is still there, and most noise reduction tools to remove the base grain sacrifice image sharpness and I feel my images look better detailed but grainy than grain-free but blurry. I'd have overall said that its sensor performs grain-wise about where good quality 35mm film at the equivalent ISO would have performed, which is below where modern DSLRs perform.

One method I have read that is supposedly good for reducing noise would be to take a burst of 5 or 6 photos and then stack them. While this technique almost certainly does work, it's not much good without a tripod, which makes me ask if there are any techniques that can greatly reduce the noise produced by old DSLRs without sacrificing image detail? The best notable technique on cameras such as the 20D that I can think of would be to shoot photos at an ISO stop above the ideal exposure, making them a little overexposed, and then digitally reducing the brightness of the RAW file by one stop, which makes shadows in the photo less grainy than they would have been had it been taken at the ideal out of the camera ISO - my 20D is pretty good at recovering highlights but performs poorly by modern standards with shadows.

Here's what a photo taken on my 20D at ISO 400 looks like if raised by 4 stops without any further editing or noise reduction:

If I'm understanding you correctly the above photo was shot taken at 400 ISO and you've increased the 'exposure' in post by four stops to get it to look as it does now. Presumably, before you raised the exposure brightness in post the image was near black and severely underexposed to the tune of at least six stops. (400 ISO = 2 stops underexposure + 4 stops raised in post = 6 stops total).

You seem to be asking a lot for a 17-year-old APS-C camera.

 

[sybersitizen]

It's fine to slightly overexpose highlights, but not by the amount that they get overblown. You can generally overexpose them on the 20D by about 1-2 stops without them becoming overblown.

If highlights are blown (exceeding full saturation) when they were not intended to be blown, they're not recoverable to their pre-blown level.

Whatever you're doing with your camera to determine exposure is the factor that might appear to leave 1-2 stops of headroom, not some other special capability.

That's the basis of the expose to the right (ETTR) school of exposure control. You use the exposure that just stops short of blowing whatever highlights you consider important, then treat the result in post as necessary to adjust the rest of the image to your desired levels. The result is what ETTR adherents would call the optimal exposure: one that preserves any important highlights while giving the rest of the scene as much light as possible.

In any case, the only point of my original post was to provide a little more info on approaches to noise control that perhaps you haven't fully explored: exposure stacking with automatic alignment, and state-of-the-art noise reduction after the fact.

 

[RJDG14]

I know it has its limitations; I was just checking that it was acting normally.

I sometimes notice on photos of the sky taken at ISO 100/200 using my 20D that I can see a small amount of subtle noise on the sky on the lightest areas of my images in the form of vertical lines. On the left is a x3 magnification of how this noise looks normally at ISO 100, and on the right I've upped the contrast of the same area of the image so you can see the noise pattern more visibly:



Some of the RAW files I could find elsewhere online from Canon's early-mid 2000s DSLRs also have this kind of pattern, which suggests that it was normal for their older models to give this form of slightly patterned noise, but I'd like confirmation that this is how the noise on RAW files from the 20D and other old DSLR models taken at a low ISO is supposed to look (it's definitely normal for there to be a small amount of noise at a low ISO)? My newer DSLR's noise tends to have a less noticeable pattern to it, however there is a 14 year difference in age between it and the 20D.

 

[Horacecoker]

I know it has its limitations; I was just checking that it was acting normally.

I sometimes notice on photos of the sky taken at ISO 100/200 using my 20D that I can see a small amount of subtle noise on the sky on the lightest areas of my images in the form of vertical lines. On the left is a x3 magnification of how this noise looks normally at ISO 100, and on the right I've upped the contrast of the same area of the image so you can see the noise pattern more visibly:



Some of the RAW files I could find elsewhere online from Canon's early-mid 2000s DSLRs also have this kind of pattern, which suggests that it was normal for their older models to give this form of slightly patterned noise, but I'd like confirmation that this is how the noise on RAW files from the 20D and other old DSLR models taken at a low ISO is supposed to look (it's definitely normal for there to be a small amount of noise at a low ISO)? My newer DSLR's noise tends to have a less noticeable pattern to it, however there is a 14 year difference in age between it and the 20D.

If you can only see this noise pattern by viewing the images at 300% and then increasing the contrast, I don't understand why you are bothered about it. It's definitely not normal to pixel peep for faults to that extent.

 

[FingerPainter]

I bought a Canon EOS 20D the other day since I wanted to see what DSLRs were like in the early-mid 2000s, and it's a pretty good digital camera for 2004, but unlike DSLRs from the past 10 years, I've noticed that grain

it's not grain. It is noise.

in the shadows of RAW files when they are raised is very obvious even at ISO 100.

Noise is a natural phenomenon in all digital images. The visibility of noise depends on the signal to noise ratio (SNR). The higher the SNR, the less noisy the image looks.

Old camera like the 20D produce nosier images than newer camera with the same sensor size for two reasons:

1. they are less efficient at turning a photon that falls on the sensor into an electrical charge, and
2. they add more noise to the noise already present in the light.

You can easily eliminate colour grain, which makes grainy raised shadows a little more viewable, but the monochrome base grain is still there, and most noise reduction tools to remove the base grain sacrifice image sharpness and I feel my images look better detailed but grainy than grain-free but blurry. I'd have overall said that its sensor performs grain-wise about where good quality 35mm film at the equivalent ISO would have performed, which is below where modern DSLRs perform.

As with any other digital camera, you minimize noise at capture time by maximising the amount of light you capture, You maximize the amount of light you capture by using the widest aperture that will still give you acceptable DOF and lens sharpness, and the slowest shutter that will still give you acceptable control over motion blur while leaving desired highlight detail unclipped.

If you still have highlight headroom at base ISO with this widest aperture and slowest shutter, then you improve SNR even more by raising the ISO setting to just before where you begin to clip desired highlight detail. On old Canons; like this, you will improve SNR more with a one stop ISO increase than you will with newer cameras, but still not as much as the SNR increase from a one stop increase in exposure (light per unit area) from widening aperture or slowing shutter. If you are clipping highlights, aways reduce ISO before narrowing aperture or speeding the shutter.

The best notable technique on cameras such as the 20D that I can think of would be to shoot photos at an ISO stop above the ideal exposure, making them a little overexposed,

Increasing ISO doesn't increase the exposure. it just increases the image lightness. "Exposure" isn't how light or dark the image is. It is the amount of light falling on the sensor per unit area.

and then digitally reducing the brightness of the RAW file by one stop,

That works reasonably well on an old Canon, but what would work even better would be to increase the aperture a stop or slow the shutter a stop, as long as you can do so without compromising DOF and motion blur.

which makes shadows in the photo less grainy than they would have been had it been taken at the ideal out of the camera ISO

If the "ideal" ISO makes images noisier, how is it ideal? As far as RAW image capture goes, the ideal ISO is the highest that doesn't clip highlight detail after you have maximized aperture and minimized shutter speed.

- my 20D is pretty good at recovering highlights but performs poorly by modern standards with shadows.

It is impossible to recover a truly blown highlight.

Here's what a photo taken on my 20D at ISO 400 looks like if raised by 4 stops without any further editing or noise reduction:

I take it that the lens was wide open and you dared not use a slower shutter speed. If so, you might have had an even better result by shooting with an ISO of 1600 and lightening only two stops in development.

It is best to start your settings with ISO at base, then set your aperture and shutter. Only if you then still have highlight headroom should you increase ISO.

If you set ISO first to something above base in an autoexposure mode, you might needlessly cause the camera to choose a faster shutter or narrower aperture. This will reduce the exposure and therefore reduce the SNR.

 

[David Pavlich]

I took this picture of the Horsehead Nebula quite some time ago. Just today, I ran it through Topaz Denoise AI. Worked pretty well:




Before denoise




After denoise

David



--
"The taxpayers are sending congressmen on expensive trips abroad. It might be worth it except they keep coming back." Will Rogers
Viewbug: https://www.viewbug.com/member/David_Pavlich

 

[alcelc]

Use the highest ISO (usually not very slow shutter speed can be used), shoot at a fast burst mode (5~10 fps) and keep shutter firing for a second or two for 10+ shots, chances on movement of the shots could be small such that normally stacking software can take care of the alignment easily.

Stack them you could find the incredible NR power.

I use this trick to shoot at ISO25600 for better than base ISO result of my system (M43).

Unfortunately it is restricted to still scenery only.