General profile questions

general questions about Neat Image
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overread
Posts: 2
Joined: Tue Mar 10, 2020 6:42 pm

General profile questions

Post by overread »

Greetings.

I've been using NI for a while now, though I've never really delved far into it. As a result in the past I used custom profiles made by others or more recently, I've been using auto generated profiles (most often using an area I pick in the photo) each time I get a new photo. Because most of my photos tend to get shown on the web this has been fairly ok for me since after resizing down for web display, a lot of noise is naturally lost anyway in the transition.

However I'm keen to advance my use of the tool and get better performance out of it.


I've had a read of the profile instructions and I think I've got the idea right, though I want to double check in case I've misunderstood something or missed something out. My plan currently is to

1) Open up the Calibration target in NI on my LCD.

2) Take photos of the screen at different ISO values. As I shoot in RAW it would seem that the only setting I need to worry about is the ISO, since most of the other listed factors that affect the noise are mostly JPEG related. Of course the photos should be slightly blurry in nature.

3) It's not mentioned in the list, but I wonder if for each ISO value if it would be worth taking photos which are not just correctly exposed, but also under exposed and then brightened in editing (to a general default value to represent the same being done to a regular photo). Staggering them to perhaps one and two stops underexposed.
I'm not sure if this is worth doing or if the actual noise patterns remain the same and the under exposure and brightening is just highlighting them more apparently to the viewer.

4) My camera can take photos in 1/3 stop values for ISO and I typically have it set up to use those 1/3rd values. Is it worth creating a fresh profile for each specific ISO value or can you double up and use the nearest ISO value (up or down?) and work with just full stop values of ISO?

5) When in the tool itself do I only need to use the "produce profile with calibration image" tool? Do I need to use any of the fine-tuning command options to further refine the result or is that simply introducing data that will degrade the overall profile

Note I'm aware that shutterspeeds are listed as a potentially contributing factor, however I'm guessing that provided I've decent lighting, I shouldn't need to concern myself with them unless I were having exposures running beyond 30seconds.


Are there any other tips or advice that would be worth taking into account when producing a selection of profiles that I've not noted above? I would be most grateful for any advice/tips regarding this matter.

overread
Posts: 2
Joined: Tue Mar 10, 2020 6:42 pm

Re: General profile questions

Post by overread »

Any neat image users left in the world?!?

lansing
Posts: 50
Joined: Sat Apr 21, 2012 6:52 am

Re: General profile questions

Post by lansing »

Hi I just started playing with Neat Image yesterday but I think I can chip in some thought on this.

To find out whether it's worth to create a different profiles for all the different ISO/exposure for your camera, the best way is to test it yourself. Do it for like different ISO, and then look at the shape of the curve created by the auto profile. If they look very much the same, that mean you can get away with the one profile fit all approach. If the curves looks different, then you'll need to have different profiles for different settings.

The whole point of profiling using a target is to save you time manually tuning it, so don't fine tune yourself, it defeated the whole purpose.

NITeam
Posts: 3126
Joined: Sat Feb 01, 2003 4:43 pm
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Re: General profile questions

Post by NITeam »

Sorry about the late reply.
overread wrote:
Tue Mar 10, 2020 7:36 pm
2) Take photos of the screen at different ISO values. As I shoot in RAW it would seem that the only setting I need to worry about is the ISO, since most of the other listed factors that affect the noise are mostly JPEG related. Of course the photos should be slightly blurry in nature.
Please remember that any post-processing applied to your RAW image after it left the camera should also be considered and taken into account. For example, if you convert a test image (a shot of the calibration target) from RAW to RGB using your preferred RAW converter working with settings A, then build a noise profile using the resulting RGB image. If you later want to reduce noise in a regular image shot also with the same camera, same camera shooting mode, but converted from RAW to RGB using that RAW converter working with settings B, then the noise in that converted image may be not exactly the same as in that test shot converted with the settings A. So you need to either keep those converter settings constant or keep track of those settings and build separate noise profiles for different conversion settings too. Of course not all conversion settings are influencing noise but some may play a role, for example exposure adjustments, sharpening, noise reduction and similar things that may be offered by the RAW converter.
overread wrote:
Tue Mar 10, 2020 7:36 pm
3) It's not mentioned in the list, but I wonder if for each ISO value if it would be worth taking photos which are not just correctly exposed, but also under exposed and then brightened in editing (to a general default value to represent the same being done to a regular photo). Staggering them to perhaps one and two stops underexposed.
Here we go, different post-processing leads to potentially different noise requiring building separate noise profiles for each of those post-processing scenarios. This complicates things, so usually it is easier to keep the post-processing constant as much as possible.

overread wrote:
Tue Mar 10, 2020 7:36 pm
4) My camera can take photos in 1/3 stop values for ISO and I typically have it set up to use those 1/3rd values. Is it worth creating a fresh profile for each specific ISO value or can you double up and use the nearest ISO value (up or down?) and work with just full stop values of ISO?
I recommend to shoot the test shots in those ISO modes that you actually use for your regular shots that you want to denoise. For example, if you only shoot full stop shots in practice, then you only want to cover those full stops with test shots for profiling. Then the ISO rates of the profiles will exactly match those of the regular shots.
overread wrote:
Tue Mar 10, 2020 7:36 pm
5) When in the tool itself do I only need to use the "produce profile with calibration image" tool? Do I need to use any of the fine-tuning command options to further refine the result or is that simply introducing data that will degrade the overall profile
You would use Auto Profile with Calibration Target when you manually open one of the test shots (of the target) into Neat Image.
You could use the regular Auto Profile on it too, but Auto Profile with Calibration Target is specifically tuned to work with those test shots.
overread wrote:
Tue Mar 10, 2020 7:36 pm
Note I'm aware that shutterspeeds are listed as a potentially contributing factor, however I'm guessing that provided I've decent lighting, I shouldn't need to concern myself with them unless I were having exposures running beyond 30seconds.

Are there any other tips or advice that would be worth taking into account when producing a selection of profiles that I've not noted above? I would be most grateful for any advice/tips regarding this matter.
overread wrote:
Tue Mar 10, 2020 7:36 pm
Note I'm aware that shutterspeeds are listed as a potentially contributing factor, however I'm guessing that provided I've decent lighting, I shouldn't need to concern myself with them unless I were having exposures running beyond 30seconds.
For the first step I would recommend to shoot for different ISOs only. Then if your working shots show some slight variance of noise strength depending on the shutter speed, then I recommend to use Auto Fine-Tune after loading one of profiles built with the test shots to fine-tune it to the current working image. That is the main purpose of Auto Fine-Tune.
overread wrote:
Tue Mar 10, 2020 7:36 pm
Are there any other tips or advice that would be worth taking into account when producing a selection of profiles that I've not noted above? I would be most grateful for any advice/tips regarding this matter.
I would print out the calibration target and shoot it from paper instead of LCD as the screen may give some glares or pixel texture that you do not want to have in those test shots.

Vlad

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