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07-29-2008, 03:11 PM   #1
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Bad Lens = Noise?

Does good lens reduce noise and bad lens don't?

i mean,if i take a shot with not a very good lens at 800 ISO and i get a lot of noise,will i get the same amount of noise,shooting at 800 ISO with a very good lens?

07-29-2008, 03:16 PM   #2
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Nope! Noise is from the sensor, not from the lens.

This being said, if you get a fast lens, you can reduce your ISO and thus reduce the noise.
07-29-2008, 04:21 PM   #3
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I'd like to spin this a little further, just for all to think about it.
What we see on a picture is a mix of the signal and the noise, we can't do much about the noise at a certain ISO, but if we can increase the signal with a constant noise our signal to noise ratio gets better and better, so even if the noise does not change, the resut should be a better image.
Ever notice how you can easily pick the well focused shots from the not so great focused shots when you preview high ISO shots? A Good vs Bad lens shot giving you a similar impression.
"A good image is always easier to sharpen" "First there have to be details to be sharpened" come to mind.

Think about it and tell me if it's something to consider.

Daniel
07-29-2008, 04:43 PM   #4
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QuoteOriginally posted by morfic Quote
I'd like to spin this a little further, just for all to think about it.
What we see on a picture is a mix of the signal and the noise, we can't do much about the noise at a certain ISO, but if we can increase the signal with a constant noise our signal to noise ratio gets better and better, so even if the noise does not change, the resut should be a better image.
Ever notice how you can easily pick the well focused shots from the not so great focused shots when you preview high ISO shots? A Good vs Bad lens shot giving you a similar impression.
"A good image is always easier to sharpen" "First there have to be details to be sharpened" come to mind.

Think about it and tell me if it's something to consider.

Daniel
Dude,...I think you lost me.

c[_]

07-29-2008, 04:43 PM   #5
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Daniel, I tend to agree.

Also, I think there's some interaction going on between the lens' sharpness characteristics (ie. not in the absolute resolution region, but slightly above it, where there is design choice) and the sensor's characteristics (pixel size, geometry, the wee lenses in there and so on). Some lenses simply lock in better on digital than film.

That still doesn't make the noise any less, but less intrusive.
07-29-2008, 09:50 PM   #6
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Nesster: Yes, i did in no way mean it would reduce the noise, just with better detail, you notice the same noise less.
Or even compare a kit lens wide open shot with a say f/5.6 shot at the same noise, you just have so much more detail to look at that the noise seems to be less. (But i'd rather keep talking about two lenses of different quality at the same aperture)
So to me a good lens can make for a better shot when you require high ISO.
07-30-2008, 06:22 AM   #7
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A similar phenomenon is observable in audio. For example, take two phono pre amps and put the same signal through each: music + record surface noise.

The better preamp will have greater headroom at high frequencies, be more stable up there as well, and therefore intermodulate with the music signal far less. The subjective experience is that any pops, cracks, and hisses are less noticeable. With the lesser preamp these aberrations overwhelm the system and result in far more subjective damage.
07-30-2008, 07:26 AM   #8
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well,i have seen that the pictures put on dpreview are far less noisy than the pictures i take....with the same camera....how is that possible?
same ISO same everything...
is there a problem with my camera?

07-30-2008, 07:30 AM   #9
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QuoteOriginally posted by Vlad Quote
well,i have seen that the pictures put on dpreview are far less noisy than the pictures i take....with the same camera....how is that possible?
same ISO same everything...
is there a problem with my camera?
what mode are you shooting

which settings are you shooting

how are you exposing

how do your histograms look

what sort of conditions are you shooting at

and so on and so forth....
07-30-2008, 09:01 AM   #10
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i shoot at 200 ISO,which is base ISO for my Camera.
on standard picture style,9F aperture i think,properly exposed,sunlight
07-31-2008, 06:56 PM   #11
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QuoteOriginally posted by Vlad Quote
Does good lens reduce noise and bad lens don't?

i mean,if i take a shot with not a very good lens at 800 ISO and i get a lot of noise,will i get the same amount of noise,shooting at 800 ISO with a very good lens?
Noise is noise, and no matter which lens is mounted, it would be the same for same conditions (iso, shutter speed, temperature)... but... here's the tricky part, if you use some crappy lens, you'll apply a lot of sharpening, maybe some clarity increase and contrast, so this way noise will be far more pronounced compared to non-sharpened image, which means if you use better lens - you'll apply less sharpening - noise should be less pronounced - final image should be less noisy with a bit more detail.
This shouldn't be right for situations under that necessary level of sharpening, let's say about 20-40 using CameraRaw, and detail extraction about the same amount, or simply - keeping it to the absolute minimum.
08-01-2008, 05:12 AM   #12
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I just thought of another example - those antique daguerrotypes and other such - where you can see the quality of the line drawn by a good lens vs a poor one, despite all the imprefections of the recording material.

Or, with 35mm film, despite the graininess of the film, you can still see the delicacy of line from a good lens, while the blur of a poor one makes the line merge with grain.

The human eye sees difference and contrast: the blur of a poor lens merges with the noise and so creates an impression of a noisy photo. A good lens maintains the separation of image from noise further down, thus the noise is less intrusive.
01-26-2011, 05:10 AM   #13
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Lens & noise

I see this topic is very old, but it is interesting for me, too. I have a Jupiter 9, 85mm f/2.0 lens and I've noticed that unresized images appear very noisy at ISO800. So, I find the question very pertinent. I asked myself also many times. I might be wrong, but I have some suppositions:
- the lens chemicals (coatings) might reduce/amplify the resulted image noise
- the lens resolution might contribute also with "details"
- more noise doesn't necessarily mean worse final image
01-26-2011, 07:43 AM   #14
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In thinking about the issue a little and also thinking about the comparison to audio systems, dolby noise reduction and in general compression and expanison schemes in general, how about the following analogy for a lens

lenses have been shown to have differing qualities, including specifically color casts and different contrast.

If we consider only contrast, a lens that has lower contrast may tend to exhibit more noise, when adjusted to the same tonal quality as a high contrast lens because you are dealing with expanding part of the range of the photo and therefore amplifying the significance of any single pixel that has a minor and unwanted variance.

bad lenses, which have low contrast due to internal reflections may exhibit "noisier" post processed shots.

What do you think?

Edit note

While the above argument may be correct for noise in the middle range of an image, a low contrast lens may actually produce better, less noisy shadow detail because it will by default bring the shadow detail more into the middle of the histogram where the resolution of the sensor is better.

so maybe what you need is a really good lens on low contrast situations and a really bad lens on high contrast situations?

Last edited by Lowell Goudge; 01-26-2011 at 07:51 AM.
01-26-2011, 11:10 AM   #15
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QuoteOriginally posted by paulpacurar Quote
I have a Jupiter 9, 85mm f/2.0 lens and I've noticed that unresized images appear very noisy at ISO800.
I have not found my Jupiter-9 85/2 to be any noisier than any of my other lenses in that focal-length vicinity. As mentioned above, noise comes from amplifying the sensor signal. You say you see noise at ISO800. What is your camera? I have read that some older models show noise above ISO 400.
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