Sharpen Amount vs Camera Resolution

  • 1
  • Question
  • Updated 2 months ago
Could I ask if the sharpen ‘amount’ slider in any way takes into account the resolution of camera being used?

If it doesn’t, given that the amount is a fixed value default, wouldn’t that mean that 20MP photos would appear to have more sharpening applied to them than 40MP ones?

Am I right in thinking that more sharpening ‘amount’ is required as the camera’s resolution increases? If so, do Adobe provide any guidance on numbers?

Thank you for your help ~
Photo of yowayowa

yowayowa

  • 20 Posts
  • 1 Reply Like

Posted 2 months ago

  • 1
Photo of Ellis Vener

Ellis Vener

  • 23 Posts
  • 11 Reply Likes
In Adobe Camera Raw and in Lightroom, capture sharpening is based on the camera sensor and resolution. The settings can be adjusted based on subject matter which falls roughly into two types: high frequency detail and low frequency detail. Typical high frequency detail type subjects are architecture, still life and product photography, and landscapes. Typical low frequency subjects are portraits, skies and seascapes.

Please note that sharpening in ACR’s and the Lightroom Develop module’s Detail panel is separate from output sharpening.

Output Sharpening in Lightroom’s Export module or in Photoshop should be based on the final size (h x w in inches/cm) and resolution (ppi or dpi) and how the final image will be presented; if printed the options are matte vs. glossy / semi-glossy, or on line.

Both Capture and Output sharpening are applied globally, I.e., to the entire area of the image.

If you want to be really picky you can do localized sharpening or softening to enhance certain details.
Photo of Todd Shaner

Todd Shaner, Champion

  • 1601 Posts
  • 540 Reply Likes
In addition the Noise Reduction settings are both camera model and ISO setting aware. Images shot at higher ISO values will have more noise reduction applied than at the same settings with lower ISO images.
Photo of Andrew Rodney

Andrew Rodney

  • 822 Posts
  • 166 Reply Likes
See: http://creativepro.com/out-of-gamut-thoughts-a-sharpening-workflow/ 
This is the basis of the sharpening workflow in LR.

The capture sharpening is based on your visual preferences using the slider. So no, it's not really taking the camera and resolution into account. 

The output sharpening (in export and print) IS taking the resolution into account and is applied on 'top of' the capture sharpening and based on the type of output: Screen or print. 
Photo of yowayowa

yowayowa

  • 20 Posts
  • 1 Reply Like
Thank you so much Ellis!

So, if I left the 'amount' slider at 25, for example, this would appear to add the same amount of sharpening to all images, regardless of resolution, as it takes that into account. I see. Really interesting.

And thank you Todd too. That is also really useful to know, regarding the noise reduction settings.

It is really great to know that Lightroom deals with all this behind the scenes. I couldn't find any of this sort of information in the online manual.

Thank you so much ~

(thank you for the article Andrew. I can't see where it contradicts Ellis and Todd. It seems to be more a Photoshop workflow using an unsharp mask?)
Photo of Andrew Rodney

Andrew Rodney

  • 822 Posts
  • 166 Reply Likes
Check out the team behind PhotoKit Sharpener and keep in mind we licensed this TO Adobe
(Edited)
Photo of Andrew Rodney

Andrew Rodney

  • 822 Posts
  • 166 Reply Likes
If you want a lot more details about the why's and how's of sharpening in ACR, LR, Photoshop, I recommend my partner, Jeff Schewe's book:
https://www.oreilly.com/library/view/real-world-image/9780321679307/
Photo of yowayowa

yowayowa

  • 20 Posts
  • 1 Reply Like
so, you are saying that the 'amount' slider in the develop module of Lightroom does not take into account the camera's sensor and resolution?

It would make sense that it did take it into account. With White Balance, for example, the camera's profile provides all the necessary offsets in order for Lightroom to simply be able to say 5600K. Other camera cameras would have different offsets within the profile to arrive at the same number for the same conditions. This keeps things simple for the user and makes it easy to be consistent with multiple cameras.

And according to Todd, it also seems that this happens with the noise reduction too.

Would it not be as Ellis said? I could imagine specific offsets being included in the camera profile so that a sharpness of 25 would be a good starting point, whether shooting with a low or high resolution camera?

I have tried playing around the the amount slider on both 20MP and 42MP images. To me, I am leaning towards the idea that Lightroom is compensating for the difference between the two cameras. As both seem to look about right at the same number on the amount slider. I was just curious to know if anyone knew for sure, as camera resolution continues to climb.

I appreciate everyone's help.
Photo of Andrew Rodney

Andrew Rodney

  • 822 Posts
  • 166 Reply Likes
What I'm saying is that you are supposed to visually adjust all those sliders, with the various preview controls, at 1:1 or greater to achieve capture sharpening. There is no 'automatic' set the capture sharpening for optimal results based on the individual sensor type let alone resolution. That is WHY you have such control over capture sharpening. That isn't the case with output sharpening. 

Let me clarify how I would have answered instead of what you got:
In Adobe Camera Raw and in Lightroom, capture sharpening is applied based on the various settings provided visually from pixels provided by your camera sensor and current resolution.
Photo of yowayowa

yowayowa

  • 20 Posts
  • 1 Reply Like
I see. Thank you for your explanation Andrew.

I do appreciate that you would assess each image individually for optimal sharpening. I understand that.

I was simply wondering if Lightroom took into account the specifics of the camera sensor, as it appears to do with variables such as white balance and noise reduction. And that appears to be the case.

This means that I do not have to increase the amount slider as camera resolutions increase, in order to achieve the same default level of sharpening.

Thank you again. Much appreciated.
Photo of Andrew Rodney

Andrew Rodney

  • 822 Posts
  • 166 Reply Likes
I was simply wondering if Lightroom took into account the specifics of the camera sensor, as it appears to do with variables such as white balance and noise reduction. And that appears to be the case.

I know of no evidence that it takes specific sensors into account for Sharpening. It does of course for other attributes like the camera profile which does play a role in what you see even before you sharpen. And of course, the resolution alone plays a huge visual role in what you see, before you even apply sharpening. 

Photo of Todd Shaner

Todd Shaner, Champion

  • 1601 Posts
  • 540 Reply Likes
Both Ellis and Andrew are correct. From my experience the camera's resolution has no affect on the LR Sharpening settings. What does affect those settings are the effective lens resolution and if the camera does NOT have a low-pass filter. Most cameras have a low-pass filter. but those that don't require less sharpening Amount and Radius setting. I'm sure you are also aware that inexpensive kit lenses generally have less effective resolution (i.e. sharpness) than more expensive lenses. As Andrew mentions you can only determine the required Sharpening settings by viewing the image at 1:1 Zoom view. What helps is to hold down the ALT key when adjusting the Sharpening Radius, Detail, and Masking control if required. You can change the LR Default Develop Settings for each camera model if you prefer different settings.
Photo of yowayowa

yowayowa

  • 20 Posts
  • 1 Reply Like
I'll admit to being confused now.

I can see that every part of the camera is important in achieving a sharp image, and I can see that for optimal results you would need to examine images individually. I'll leave all these other aspects for the moment. (as Andrew pointed out, there is enough there for the subject of a book).

As far as default settings are concerned, I can see that Lightroom provides the same default 'amount' setting (currently 40) regardless of the cameras resolution (any many other particulars too).

So my question is, is Lightroom in anyway considering the resolution of the image when it adds this default 'amount' of sharpening?

I ask because if the answer is no, surely the user would gradually end up with greater amounts of sharpening over the years as camera resolutions increased. In order for the effect of the sharpening to remain visible.

Todd, when you say "the camera's resolution has no affect on the LR Sharpening settings", does that mean that 1) Lightroom ignores the resolution of the camera and in that sense the sharpening is dumb? Or does it mean 2) that because Lightroom is considering the camera's resolution and compensating for it, you get consistent results.

I'm sorry for the confusion.

Photo of Andrew Rodney

Andrew Rodney

  • 814 Posts
  • 162 Reply Likes
So my question is, is Lightroom in anyway considering the resolution of the image when it adds this default 'amount' of sharpening?
Considering? Sharpening IS resolution dependent so in that context yes. The slider will affect 100x100 pixels differently than 1000x1000 pixels. True in Photoshop or any application that 'sharpens' pixels and again, based visually on how you alter the settings to do so. 

LR will operate on images it has absolutely zero idea how they were generated; camera, scanner etc. But it does operate based on the pixels provided. So the 'idea' that LR somehow examines the sensor to do its thing is, AFAIK, speculation. I've seen nothing about this in any of Jeff's book either. 

LR/ACR/PS and all other such applications have zero idea about images in context. They simply deal with pixels; virtually one at a time. With know AI about adjacent pixels. Humans do this however. And we adjust images, sharpening or otherwise based on images in context. LR/ACR/PS have no idea if the image contains high or low frequency over the entire image. You do. 
Photo of yowayowa

yowayowa

  • 20 Posts
  • 1 Reply Like
thank you Andrew. I am pretty sure that I understand what you are saying.

So, if Lightroom is simply sharpening based on the pixels it sees in front of it, an amount, and a radius (and is not drawing upon any information/metadata about the camera's sensor or resolution), would that mean that a fixed value, for example 40, would appear to have done less to a 100MP image than a 10MP one? (presuming that both images were viewed at the same size rather than at 1:1).

in summary, broadly speaking, are we likely to be using higher values for the 'amount' slider as camera resolutions increase? or, am I wrong in thinking that more sharpening is required in order to still see the same effect on higher resolution images? (again, viewed as a complete image, not 1:1).

Thank you again
Photo of Todd Shaner

Todd Shaner, Champion

  • 1601 Posts
  • 540 Reply Likes
in summary, broadly speaking, are we likely to be using higher values for the 'amount' slider as camera resolutions increase? or, am I wrong in thinking that more sharpening is required in order to still see the same effect on higher resolution images? (again, viewed as a complete image, not 1:1).
Capture sharpening is not image resolution dependent because it is only applied to fine detail image areas as edge enhancement. The size of the edge that is sharpened is determined by the Radius setting, which has nothing to do with the actual image size in megapixels.

https://en.wikipedia.org/wiki/Unsharp_masking

Where you will see a need to use higher sharpening settings is if the camera sensors resolution (line pairs/mm) significantly exceeds the effective lens resolution (MTF). Canon even goes so far as to recommend specific lenses for use with their 5DS 50 megapixel camera to help insure the best performance (i.e. sharpness). 

https://www.the-digital-picture.com/News/News-Post.aspx?News=15356
(Edited)
Photo of Andrew Rodney

Andrew Rodney

  • 822 Posts
  • 166 Reply Likes
In a word: Yes. 
Photo of yowayowa

yowayowa

  • 20 Posts
  • 1 Reply Like
thank you so much everyone. i will read all the linked articles carefully. I would like to have a better understanding of what is a fairly complex subject.

as far as I can make out at this stage:

1) the resolution of the image is relevant to the amount of sharpening required, though, the two concepts are not linked in a linear or predictable way.

2) it seems unlikely that the sharpening panel in the develop module is using any metadata or camera information to compensate for camera resolution.

3) the sharpening panel may take into account the lack of an AA filter, though we are not sure.

I will carry on reading....
Photo of Todd Shaner

Todd Shaner, Champion

  • 1543 Posts
  • 522 Reply Likes
1) Yes, with reference to the sensor resolution versus lens resolution. It is predictable, but the math is beyond me and the scope of this post. Some more info here: https://www.dpreview.com/forums/thread/4232075
2) Correct.
3) I tested this using raw files from the Canon 5DS (has low-pass filter) and 5DS R (low-pass filter removed) and the 5DS R is clearly sharper using the same Sharpening settings. This pretty much confirms that the LR and ACR Sharpening controls do not read or use the camera or lens information.