Understanding Noise

USAIR · March 3, 2005

Ok I need some help from the experts.
Some of you know I just picked up the 20d
And as you can tell from almost all my post, I like to shoot nightshots

I have recently decided to give stock photography a try it took me a few times to be accepted by the administrators because of noise.
Also been told from others that there is noise in this photo and in that photo.
I have several questions... first how to spot noise and I am not talking about obvious noise that’s easy I am talking the hard to spot.

Also, how can I shoot to eliminate the noise? Keep a high shutter speed? Keep a certain aperture?
Is it like any other camera settings kind of a trade off to use the settings that gets the shot you want?

Is there a way to spot noise in ps ..I mean to make it stand out?
Maybe I am introducing noise from my ps possessing?

This is what I usually do ...
I shoot in raw
I then get the color correct
Then I move the exposure slider up if needed(sometimes not)
Then I sharpen about 50%
Then I convert to jpg
I go to curves to set black point then white point
If I want(need) I up the saturation
Then usm Amount 50%, radius 1, and threshold 2
Save jpg, Quality 12 maximum, format options baseline standard

I also am assuming the 20d is ok

My photos look good to me I really can't see the noise
I know my shots look like a travel brochure for Kentucky and Ohio
That’s cool I like them I just don't see the noise.

Thanks
Fred

John Mueller · March 3, 2005

Fred,all that time @ the airport and the noise just now gets to you

I wont be much help here,but have you tried any noise reduction sw?

fish · March 3, 2005

In general, high ISO produces noise. What ISO are you shooting at?

Could you post one of the images that you think is too noisy with the EXIF data?

USAIR · March 3, 2005

Hi John

MHJS wrote:

Fred,all that time @ the airport and the noise just now gets to you
I wont be much help here,but have you tried any noise reduction sw?

Yes I know I can't hear and I can't see.

I have not tried noise software with the 20d photos yet hoping not to have too.

Thanks
Fred

USAIR · March 3, 2005

Fish

fish wrote:

In general, high ISO produces noise. What ISO are you shooting at?

Could you post one of the images that you think is too noisy with the EXIF data?

When I shoot nightshots iso is always 100 with tripod and manual mode.
Here's a couple

Manual f2.8 1/10 sec iso 100

Manual f22 13 sec iso 100

Manual f22 4 sec iso 100

Thanks
Fred

wxwax · March 3, 2005

You're doing a couple of things in post which increase the noise in your shots.

You sharpen the image twice: once in RAW, and then a second time as a jpeg. Sharpening brings out noise, especially in a high ISO shot. BTDT

You also play with the exposure slider in RAW. Again, in a high ISO shot, that will increase the noise. BTDT

That's why I firmly believe that the exposure on a high ISO shot has to be dead-on in camera. You hafta to treat a high ISO shot very delicately in post.

I wonder if color correcting can also raise the noise level? It might be safer to do a custom white balance in the field. Again, the goal is to make the image as close to perfect as possible... in the camera.

I'm also interested to see that you go from RAW straight to jpeg. That means you're going from a 16-bit image to an 8 bit, then doing more post processing. I wonder (I don't know) if it might be better to save the image as a 16 bit TIFF or Photoshop file, finish your processing, then reduce it to 8-bits and jpeg?

Steve Cavigliano · March 3, 2005

Fred,

Using ISO100 is good

May I ask, when do you shoot your night shots?

The reason I ask is that the hour after sunset seems to be the best time to capture night shots. There's not as much difference in the lights and the sky. The difference is so great after this time, that you usually have to under expose the sky so as to not blow out the lights. No matter what ISO you use, under exposure = noise. The more you under expose, the more noise will be present. Pushing the RAW exposure just helps to make the noise more visible

If you already knew this, I apologize for the recap. I found this info to be true the hard way and was given most of the above info by Shay Stephens. Who, BTW, has done some awesome night shots. With a small sensored digital, no less

You should really try some of the fine noise removal software packages that are out there. You can adjust the intensity and with some that work as plug-ins you can even mask off areas. IOW, you can just apply NR to the sky portion of the image, if you choose to do so.

Neat Image, Noise Ninja, Noiseware, Helicon, etc....

I have a shot that I ran through 4 NR sw programs, if you'd care to check them out. It's not a night shot, but a high ISO shot. So the issue is similar.

Here's the original crop:
http://www.pbase.com/slo2k/image/25560017/original

Click "Next" to see the next example.

Steve

USAIR · March 3, 2005

Sid

wxwax wrote:

You're doing a couple of things in post which increase the noise in your shots.

You sharpen the image twice: once in RAW, and then a second time as a jpeg. Sharpening brings out noise, especially in a high ISO shot. BTDT

You also play with the exposure slider in RAW. Again, in a high ISO shot, that will increase the noise. BTDT

That's why I firmly believe that the exposure on a high ISO shot has to be dead-on in camera. You hafta to treat a high ISO shot very delicately in post.

I wonder if color correcting can also raise the noise level? It might be safer to do a custom white balance in the field. Again, the goal is to make the image as close to perfect as possible... in the camera.

I'm also interested to see that you go from RAW straight to jpeg. That means you're going from a 16-bit image to an 8 bit, then doing more post processing. I wonder (I don't know) if it might be better to save the image as a 16 bit TIFF or Photoshop file, finish your processing, then reduce it to 8-bits and jpeg?

So is it better to sharpen in raw or wait to sharpen the final jpg ?
I have always underexposed my nightshots a little
I thought this would reduce noise.

I set wb when shooting sports photos but never do this at night
I guess I will give it a try I use a white paper inside.

Thanks
Fred

wxwax · March 3, 2005

USAIR wrote:

So is it better to sharpen in raw or wait to sharpen the final jpg ?
I have always underexposed my nightshots a little
I thought this would reduce noise.

I set wb when shooting sports photos but never do this at night
I guess I will give it a try I use a white paper inside.

Thanks
Fred

Fred, AFAIK, any sharpening at all will increase the noise.

Why do you underexpose your night shots? Is it to avoid burned-out highlights from lights, etc? If so, why not make two perfect exposures - one for the lights/bright bits, and one for everything else? Then mask them together into one image in Photoshop. It's easy to do, and means you don't have to play with the dreaded "Exposure" slider, the source of so much high-ISO noise.

If you're serious about selling your work, why not spend the money to get a proper white balance card? White paper can work (TV shooters use it all the time) but it may not be 100% accurate.

USAIR · March 3, 2005

Steve

Steve Cavigliano wrote:

Fred,

Using ISO100 is good May I ask, when do you shoot your night shots?

The reason I ask is that the hour after sunset seems to be the best time to capture night shots. There's not as much difference in the lights and the sky. The difference is so great after this time, that you usually have to under expose the sky so as to not blow out the lights. No matter what ISO you use, under exposure = noise. The more you under expose, the more noise will be present. Pushing the RAW exposure just helps to make the noise more visible

If you already knew this, I apologize for the recap. I found this info to be true the hard way and was given most of the above info by Shay Stephens. Who, BTW, has done some awesome night shots. With a small sensored digital, no less

You should really try some of the fine noise removal software packages that are out there. You can adjust the intensity and with some that work as plug-ins you can even mask off areas. IOW, you can just apply NR to the sky portion of the image, if you choose to do so.

Neat Image, Noise Ninja, Noiseware, Helicon, etc....

I have a shot that I ran through 4 NR sw programs, if you'd care to check them out. It's not a night shot, but a high ISO shot. So the issue is similar.

Here's the original crop:
http://www.pbase.com/slo2k/image/25560017/original

Click "Next" to see the next example.

Steve

Well as you can see from the post above I thought the opposite about noise.
I try to shoot in that time frame but I seem to never know when to quit
I would say a lot of my shots are after the one hour good time my skys are very dark.

I will have to rethink how I do my nightshots
I have seen Shay's work with 717 it's amazing.

Thanks Steve for the help
Fred

USAIR · March 3, 2005

Sid

wxwax wrote:

Fred, AFAIK, any sharpening at all will increase the noise.

Why do you underexpose your night shots? Is it to avoid burned-out highlights from lights, etc? If so, why not make two perfect exposures - one for the lights/bright bits, and one for everything else? Then mask them together into one image in Photoshop. It's easy to do, and means you don't have to play with the dreaded "Exposure" slider, the source of so much high-ISO noise.

If you're serious about selling your work, why not spend the money to get a proper white balance card? White paper can work (TV shooters use it all the time) but it may not be 100% accurate.

I am serious about selling my photos even if I don't I still would like to get it correct.
I have Kodak gray cards one 4x5 and two 8x10 not sure where I even got these from someone gave them to me.

I have messed around with blending but not too much.
I will give all these ideas a try and see which will work best for the way I shoot

Thanks again

Fred

ginger_55 · March 3, 2005

Questions this noise issue has raised for me
I just asked a question about the NR programs elsewhere, I do need to know which one.

However, I am confused re RAW files having to be spot on. I agree anything is easier to work with that needs no work, but one reason that has been put fwd as a reason to shoot RAW is that you can change exposure by up to two stops.

I have found that there is no way you can really change the exposure if it is blown..............so there goes that. Now I hear that I shouldn't be changing the underexposed shots either. I really did think that has been put fwd as possible and not a problem, in the long run.

Now I am assuming that you can still change the WB without introducing more noise? Is that true?

Also, re the sliders on the RAW adjustment thing, there is one for luminance, I usually raise it to 5 automatically. There is also one for noise. Since I don't like being told that noise is ruining a photo, I automatically raise it to 35, from 25, since I am afraid that I am going to do something to raise the noise level.

I have also become paranoid about sharpening. I sharpen as little as possible so that when someone says it is oversharpened, I know that is not the problem. I only USM once at about 60, and that is if no noise is showing at the time. I used to do that, then do it the lab way and then do it the luminesence way, and everything seemed fine. I had problems with one picture and I stopped doing that.

I only use USM once.

ginger

ginger_55 · March 3, 2005

Steve Cavigliano wrote:

Fred,

Neat Image, Noise Ninja, Noiseware, Helicon, etc....

I have a shot that I ran through 4 NR sw programs, if you'd care to check them out. It's not a night shot, but a high ISO shot. So the issue is similar.

Here's the original crop:
http://www.pbase.com/slo2k/image/25560017/original

Click "Next" to see the next example.

Steve

Do you mean that you have all four programs on your computer and that you ran that one image through each program, so that it basically was noise reduced 4 times, each time with a different program?

I might as well mention the WB card. What is that? I thought we were using grey cards?

ginger (getting more confused by the moment)

wxwax · March 4, 2005

ginger_55 wrote:

However, I am confused re RAW files having to be spot on. I agree anything is easier to work with that needs no work, but one reason that has been put fwd as a reason to shoot RAW is that you can change exposure by up to two stops.

I have found that there is no way you can really change the exposure if it is blown..............so there goes that. Now I hear that I shouldn't be changing the underexposed shots either. I really did think that has been put fwd as possible and not a problem, in the long run.

Now I am assuming that you can still change the WB without introducing more noise? Is that true?

Hi Ginger

The problem is when you shoot at ISO 1000 or ISO 1600. Try it and see. If you underexpose a shot at those ISO levels, and then raise the exposure on your RAW, you'll get more noise. I say this because I've seen it repeatedly.

I don't know that changing the white balance adds more noise.

My point is that if you shoot at a really high ISO, you get the best results if you expose the photo properly in the camera. No shortcuts. That's probably true all the time, but it's especially true at high ISO, where there seems to be very little tolerance for post processing.

ginger_55 · March 4, 2005

wxwax wrote:

Hi Ginger

The problem is when you shoot at ISO 1000 or ISO 1600. Try it and see. If you underexpose a shot at those ISO levels, and then raise the exposure on your RAW, you'll get more noise. I say this because I've seen it repeatedly.

I don't know that changing the white balance adds more noise.

My point is that if you shoot at a really high ISO, you get the best results if you expose the photo properly in the camera. No shortcuts. That's probably true all the time, but it's especially true at high ISO, where there seems to be very little tolerance for post processing.

Thanks, Sid. I solved the whole problem (not), I did buy Noise Ninja.
I am really having a problem switching back and forth on subject matter, and sunsets. Something always seems set wrong.

g

gubbs · March 4, 2005

This has reminded me about a question I meant to ask a while back.
If you shoot in RAW is any WB information stored within the image?

I was under the impression that setting the wb, custom or otherwise, was like setting the sharpening or saturation within the camera ie it would be recorded within a camera jpg but discarded in a raw file and was therefore a waste of time.

Now I'm not so sure and was wondering if it was more akin to setting the exposure. So once its set you have say +/-7000 to play with when processing

USAIR · March 4, 2005

Spoting Noise
No one commented on the photos noise wise
Is the noise is the photos I provided that obvious?
#1 I guess I see the noise
Is is hang in there grasshopper you will get the "eye" to spot noise someday
Do I magnify to 100% and look around.

Thanks
Fred

USAIR · March 4, 2005

gubbs wrote:

This has reminded me about a question I meant to ask a while back.
If you shoot in RAW is any WB information stored within the image?

I was under the impression that setting the wb, custom or otherwise, was like setting the sharpening or saturation within the camera ie it would be recorded within a camera jpg but discarded in a raw file and was therefore a waste of time.

Now I'm not so sure and was wondering if it was more akin to setting the exposure. So once its set you have say +/-7000 to play with when processing

I also would like to know this
My guess is shooting in raw has no effect on wb
Just like setting the sharpness would
Should be easy to test I think?

Fred

gubbs · March 4, 2005

USAIR wrote:

No one commented on the photos noise wise
Is the noise is the photos I provided that obvious?
#1 I guess I see the noise
Is is hang in there grasshopper you will get the "eye" to spot noise someday
Do I magnify to 100% and look around.

Thanks
Fred

Fred, its difficult to see the noise at that size, can you post up some 100% crops?

Steve Cavigliano · March 4, 2005

ginger_55 wrote:

Do you mean that you have all four programs on your computer and that you ran that one image through each program, so that it basically was noise reduced 4 times, each time with a different program?

I might as well mention the WB card. What is that? I thought we were using grey cards?

ginger (getting more confused by the moment)

Ginger,
Yes. I took the original crop and ran it through each of the 4 programs individually. I probably didn't use "optimum" settings for each, but it does give you some idea of the results you can expect from each.

FWIW, that was an image from a 717. The noise at high ISOs on a small sensored digital is much different than the grain you see with the 20D. If you look at the original, there's blotchy clumps of noise on the skin. You have to really crank up the NR settings to minimize it. Not so with 20D high ISO pics. You can get by with much lower settings.

WB card = either a gray card of any white object you care to white balance off of. On my Sonys I found that a styrafoam coffee cup fit perfectly over the end of the lens. So I'd put one on, point the lens at the light source and push the manual wb button. Volia, super colors

:

Steve

Steve Cavigliano · March 4, 2005

USAIR wrote:

I also would like to know this
My guess is shooting in raw has no effect on wb
Just like setting the sharpness would
Should be easy to test I think?

Fred

Fred,
The image file does contain the wb info. At least I see it when using ACR to do conversions. It shows the wb as "as taken" or "as shot" or something like that. You are correct that shooting in RAW doesn't effect wb. But, it does make it a whole lot easier to correct wb after the fact, using the "white dropper" or temp/tint sliders in ACR. Rather than having to use curves. levels, color balance, etc to correct wb on a jpg.

Steve

wxwax · March 4, 2005

Steve Cavigliano wrote:

Fred,
The image file does contain the wb info. At least I see it when using ACR to do conversions. It shows the wb as "as taken" or "as shot" or something like that. You are correct that shooting in RAW doesn't effect wb. But, it does make it a whole lot easier to correct wb after the fact, using the "white dropper" or temp/tint sliders in ACR. Rather than having to use curves. levels, color balance, etc to correct wb on a jpg.

Steve

gubbs · March 4, 2005

Steve Cavigliano wrote:

Fred,
The image file does contain the wb info. At least I see it when using ACR to do conversions. It shows the wb as "as taken" or "as shot" or something like that. You are correct that shooting in RAW doesn't effect wb. But, it does make it a whole lot easier to correct wb after the fact, using the "white dropper" or temp/tint sliders in ACR. Rather than having to use curves. levels, color balance, etc to correct wb on a jpg.

Steve

Thanks Steve,
so there is no advantage in setting a custom wb if you shoot in raw? (other than you shouldn't have to adjust again when processing)

wxwax · March 4, 2005

gubbs wrote:

Thanks Steve,
so there is no advantage in setting a custom wb if you shoot in raw? (other than you shouldn't have to adjust again when processing)

Ah, but that's a big advantage, don't you think? At a minimum, getting it right in the camera is a huge timesaver.

And if your shot doesn't have a good white, black or middle grey for the eyedropper thingie, then you're left to wander with the white balance slider, trying to get it right. Much better to get it right in camera (says the man who's never custom white balanced in his miserable life.

)

I'm edging ever closer to doing it right, tho.

Steve Cavigliano · March 4, 2005

gubbs wrote:

Thanks Steve,
so there is no advantage in setting a custom wb if you shoot in raw? (other than you shouldn't have to adjust again when processing)

Gubbs,
I agree with Sid's point about getting it right in the camera. That way you can use the attached jpg instead of the RAW image if you so desire and it makes viewing the image in the LCD a whole lot more enjoyable/accurate.

Steve

gubbs · March 4, 2005

wxwax wrote:

Ah, but that's a big advantage, don't you think? At a minimum, getting it right in the camera is a huge timesaver.

And if your shot doesn't have a good white, black or middle grey for the eyedropper thingie, then you're left to wander with the white balance slider, trying to get it right. Much better to get it right in camera (says the man who's never custom white balanced in his miserable life. )

I'm edging ever closer to doing it right, tho.

Thanks Steve and Sid, yep, I agree it's an advantage but not always practical, I've never done it either

. I was just trying to work out what's going on. I thought I understood but then I was chatting to Luben who'd read something to the contrary and it got me thinking

USAIR · March 5, 2005

Thanks everyone
Looks like I have a lot to think about and to work on nothing hard
I just think I need to change the way I would do things

The only thing that kind of puzzles me is the way to post process
Especially about the types of files to use and what to convert to and when

It might help if someone could list his or her workflow on this or maybe a link where I could read up on this.
Just when I started to feel I know something about this I found I don't know jack.

Thanks

Fred

wxwax · March 5, 2005

USAIR wrote:

Looks like I have a lot to think about and to work on nothing hard
I just think I need to change the way I would do things

The only thing that kind of puzzles me is the way to post process
Especially about the types of files to use and what to convert to and when

It might help if someone could list his or her workflow on this or maybe a link where I could read up on this.
Just when I started to feel I know something about this I found I don't know jack.

Thanks
Fred

Have you tried a search using the keyword 'workflow'? I reckon there have been a few posts about it already. Tons of stuff on the internet too. Worth a Google.

Seamus · March 5, 2005

USAIR wrote:

Looks like I have a lot to think about and to work on nothing hard
I just think I need to change the way I would do things

The only thing that kind of puzzles me is the way to post process
Especially about the types of files to use and what to convert to and when

It might help if someone could list his or her workflow on this or maybe a link where I could read up on this.
Just when I started to feel I know something about this I found I don't know jack.

Thanks
Fred

Hi Fred, I don't know what software you are using? This is a link to a workflow for photoshop cs that can be adapted for elements (which I have)

http://www.fredmiranda.com/A11_Nori/

or

http://luminous-landscape.com/techniques/process.shtml

I will probably be murdered for this but this is my workflow:

I: examine photo in elements viewer at 100%. If it is out of focus (oof) or really dark or obviously blown highlights it gets binned.

2: For me that cuts the list down from 700 to 3

3: crop image.

4: In elements go to layers, adjustments, levels. hit auto.

5: Levels, adjustments, brightness / contrast. put contrast between 5-10.

6: levels, adjustments, colour / saturation. put saturation between 8-12.

7 flatten image. Levels, flatten image.

8:Sharpen image. Filters, sharpen, unsharpen mask, amount between 100-300 (watch for noise), radius 0.3, threshold 0.

9: save image.

10: post the image and ask for feedback.

11: when feedback points out the 101 things wrong with the image go to step 1.

If you can't be bothered to do all this just crop, hit auto fix then sharpen and save.

Buy a book. I have Scott Kelby's book on elements 3. It is very good and explains things so I can understand them.

I hope this helps.

Shay.

ginger_55 · March 5, 2005

I am learning one thing re that workflow, and since I have done nothing but the bad part of photography today, part of which was learning what a F histogram means...............and reading and reading. And trying to get my flash to work with my new camera, for a baptism tomorrow.

I have learned everywhere.

NEVER, NEVER USE BRIGHTNESS /CONTRAST, LEVELS IS THE ONE TO USE.

I have been reading that in more places, and it was just in the book I was reading. The reason is that say you want something brighter, if you brighten it with "brightness" it does the whole photo thereby taking out the shadows, same with the highlights if you go the other way. And contrast irretrievably takes something out, too. Whereas levels just deals with say brighter middle and leaves the blacks alone.........

That has been my day and more and more... All I want now is a cookie.

ginger:D

Understanding Noise

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