Thought on Capture Sharpen

[Ollokot]

Hi Folks,
I use a capture sharpen of amount-300% and radius-0.3 on all my images after I have done with ACR and any noise reduction deemed necessary,maybe I have totally lost the plot but I have been thinking about the sharpening available in ACR of amount 150% and radius 0.5(the lowest available) and was wondering can this be set in a way that gives the exact amount of sharpening as 300%@0.3, I use canon and their recommended sharpening of those settings.
Have I lost the plot,
Pat.

[Colin Southern]

Hi Pat,

The general rule is "anything you CAN do in ACR you SHOULD do in ACR", but I make an exception when it comes to sharpening for this very reason. Although having said that - to be honest - capture sharpening really doesn't do anything that's visible unless one is pixel peeping.

Canon recommend 300% @ 0.3 or 250% @ 0.3, but they also recommend a threshold of 1 at base ISO increasing to 6 or 7 at very high ISO modes, whereas I just use threshold 0 at base ISO. The only exception to this can be up-close studio portraiture where I've noticed that it can make skin a bit waxy, so I sometimes drop it back a bit.

To answer your question though, I don't think it would make much difference.

On another note though, conventional wisdon says that one should always apply noise reduction before sharpening, but in my experience, noise reduction is just another name for "blurring" and thus, is pretty much the opposite of sharpening - and the 2 cancel each other out (at the capture sharpening level). I've had images where I've been a good boy - did noise reduction first - noted how the noise was reduced - applied capture sharpening - and watched the noise pop right back in again. So best thing with noise is to simply avoid it in the forst place by not under-exposing and not cropping excessively.

[Ollokot]

Hi Colin,
Thank you for your reply,I also do no sharpening in ACR and sometimes wonder is it worth capture sharpening at all,and as to noise reduction I hate it because of the softening it introduces and as you say try to avoid it in the first place.
Best Wishes,Pat

[dje]

Hi Colin and Pat

The capture sharpening figures of 300% and 0.3 pixel can only be applied in PS, not ACR which has a max of 150% and min of 0.5 pixel. So are you saying that you dont apply any capture sharpening in ACR because it cant do the recommended Canon figures ? Sorry if I'm asking the bleeding obvious but I'm a bit slow this morning

Dave

PS : I think Pat has just answered my question

[Dave Humphries]

Colin taught me nearly everything I know about sharpening, so it is no surprise I largely concur with his practices and figures.

These days, if I capture sharpen at all, I'd still do it in CS5/Elements at 0.3px - because 0.5px is too wide. Let me explain why;

I always aim to produce a shot that can be used for a wallpaper on my PC (and display big in the Lytebox here at CiC), so anything up to 1000 tall and/or upto 1900 wide, but more often say, 1600 wide. I always prefer to reach these dimensions with a minimum 2:1 downsize to benefit from the noise reduction and sharpening advantages it brings, which means I am looking for an image size after cropping of say 3200-3800 x 2000 px. My 12MP cameras produce either 4288 x 2848 or 4000 x 3000px RAW captures as a starting point.

If you apply 0.3px capture sharpening, then downsize 2:1 it interpolates out at 0.15px (either 0.1 or 0.2 in reality) and is invisible - and more to the point, it won't get made worse in final sharpening. If you apply 0.5px capture sharpening, it almost certainly still contributes, in an irregular manner, to the post downsized image at 0.25px (either 0.2 or 0.3 in reality) and then gets amplified when final sharpening (also at 0.3px) is applied.

Before anyone says 'you can't see less than one pixel' - the image is oversampled at 10x the resolution while open in the image editor, (that's how they apply such small radii) - so the sub-pixel radius edges will remain - and 'bite you' if you're not careful.

If I do content/creative sharpening, I am always wary of the downsize ratio I will be applying in choosing the radius and amount and may apply sharpening in 2 passes, say for a slightly off focus bird. If necessary, I'll try it, downsize and output sharpen, then undo those 4 steps for another go if I'm unhappy.

Think of distant small bird in shady forest on an overcast day.
If I have a fairly noisy image (say iso 800 and above) that I also know I am going to have to crop fairly excessively (below my 'ideals' above but I don't want to bin it). Then I use Neat Image to noise reduce because it largely avoids the re-appearance problem Colin describes, due to the way it works.

If I have a really high iso, overly cropped shot, I seem to get two kinds of noise; the fine/colour noise, dealt with as above, but also randomly scattered small clumps of dark pixels that look like ground pepper on the image, these can be quite tricky to deal with - possibly even necessitating their individual removal with spot healing tool where they cause the most visual distraction. I have occasionally seen this in other's images too, so I know it's not just me. If the image is this bad, it gets no sharpening until after the downsize - these days it is more likely to be binned though.

Anyways, the above is how I work, for what I shoot and what I do with my images, I'm not saying it is right for everyone, especially if you print, things may be different.

Hope that helps,

[Colin Southern]

Hi Colin and Pat

The capture sharpening figures of 300% and 0.3 pixel can only be applied in PS, not ACR which has a max of 150% and min of 0.5 pixel. So are you saying that you dont apply any capture sharpening in ACR because it cant do the recommended Canon figures ?

In a word, "yes"

[Boatman]

I've been getting good results in ACR and LR4b with sharpening, now called 'Detail', settings at:
Mask ~75
Detail ~75
Radius ~.8
Amount 50-100
Of course, it all depends upon the image and the camera as to what will work best. I'm discovering that the masking can be set quite high, which eliminates sharpening the noise while the true edges can be sharpened quite hard.

[Colin Southern]

I've been getting good results in ACR and LR4b with sharpening, now called 'Detail', settings at:
Mask ~75
Detail ~75
Radius ~.8
Amount 50-100
Of course, it all depends upon the image and the camera as to what will work best. I'm discovering that the masking can be set quite high, which eliminates sharpening the noise while the true edges can be sharpened quite hard.

Hi Homer,

Yes, but these are more content/creative sharpening settings - not capture sharpening settings.

[IanCD]

Hi Colin,
What is it that makes these content / creative rather than capture sharpening settings?
I've been using LR3 for a while (and have played with LR4b a bit).
By default (as installed) on Import, LR3 applies sharpening at Amount = 25, Radius = 1.0, Detail = 25. Martin Evening, in The Lightroom 3 Book refers to this as Input / Capture sharpening, as distinct from Output sharpening.
I'm not raising this to argue a point, but because I'm still confused - despite having read a LOT of stuff now - about sharpening processes.
LR sharpens on import. I can change the default settings, but I sometimes find it difficult to see the difference in the results (maybe it's time for new glasses ).
Sharpening is applied again on export (I guess this is the downsizing step Dave refers to above). Sharpen for screen, or glossy / matte paper, High, srandard or low amount.
Then when I upload to SmugMug the default is that they're sharpened again...!??? The settings on SmugMug are amount, radius, threshold and sigma.
Ian

[herbert]

Hi Colin,
Thank you for your reply,I also do no sharpening in ACR and sometimes wonder is it worth capture sharpening at all,and as to noise reduction I hate it because of the softening it introduces and as you say try to avoid it in the first place.
Best Wishes,Pat

If I have a photo where the noise is a problem it is usually in areas where there is no detail. My workaround it to double process the image through ACR. I crank up the noise reduction to eliminate the problems areas for the first image and the second I import with no noise reduction. The second one is then capture sharpened for the detail areas. I can then blend the two layers in photoshop to get the best of both worlds.

The difference between USM 300% @ 0.3 px and ACR sharpen 150% @ 0.5 px is hard to tell. But because Colin says the former is the way to do it then that is my workflow for images that pass through photoshop.

For an image where you want to do a bit of work to make a good print then the extra few minutes work doing a double image processing is worth it. I spend more time on the rest of the processing steps so this work is relatively cheap time wise.

For images that are downsized for the web then noise is sampled out anyway. No need to really worry about it. Likewise for web output I don't capture sharpen and then content sharpen my images. I just skip straight to content sharpening by using the fast masking and sharpening tools in ACR. Easy to do 100 images in a few seconds for the same type of image. These images rarely go through Photoshop anyway so it is easy to do it all in ACR (using Lightroom).

Alex

[Colin Southern]

Hi Colin,
What is it that makes these content / creative rather than capture sharpening settings?
I've been using LR3 for a while (and have played with LR4b a bit).
By default (as installed) on Import, LR3 applies sharpening at Amount = 25, Radius = 1.0, Detail = 25. Martin Evening, in The Lightroom 3 Book refers to this as Input / Capture sharpening, as distinct from Output sharpening.

Hi Ian,

Capture sharpening is needed to account for softening due to 3 things:

- The cameras digitization process

- The cameras anti-aliasing filter, and

- The RAW conversion anti-aliasing process

What's needed is agressive sharpening, but over a tiny area of influence - Canon's recommendation is an amount 250 - 300% over a radius of 0.3 pixel, which LR's "Amount = 25, Radius = 1.0" doesn't sound close to. On the other hand, typical content / creative sharpening varies, but 40% @ 4 pixels is one I typically use -- which sounded a LOT closer to the LR figures you quoted.

I could be wrong - one of the things that drives me nuts about Lightroom is that the adjustments aren't calibrated in absolute measurements - so "Amount = 25" may in fact be the same as "300% in ACR", but I don't think so.

Perhaps someone else could clarify that point (no pun intended )

[Colin Southern]

The difference between USM 300% @ 0.3 px and ACR sharpen 150% @ 0.5 px is hard to tell. But because Colin says the former is the way to do it then that is my workflow for images that pass through photoshop.

That may appear very "guru" of me, but I really should point out that 300/0.3 is actually Canon's recommendation, not mine (although - based on the assumption that they know more about it than me, I of course follow it too).

On a side note, I got bitten in the bum not too long ago with this -- I was rush processing some initial selects, and I "cheated" by having ACR apply some more agressive sharpening than usual automatically to the images (so 800px down-samples didn't need any further work -- I was exporting straight out of Bridge -> JPEG). And of course I forgot that it was turned on when I started processing full resolution images from a location shoot -- took me ages to figure out why the images started to fall apart with my normal sharpening reigme

So these days I just like to leave all sharpening to Photoshop - at the end of the day, it only takes 1 click of the "Capture Sharpen" button in my actions panel.

[Geoff F]

ACR in CS5 has an auto default sharpen of 25 at 1 radius, unless you specifically alter the setting.

I have recently been using 50 at 0.5 instead, which appears to give a better 'capture sharpen' effect.

But I'm not really sure what is the perfect answer here, or why ACR uses the default setting that it does.

[Colin Southern]

ACR in CS5 has an auto default sharpen of 25 at 1 radius, unless you specifically alter the setting.

Hi Geoff,

Just checking that you know that it only applys this sharpening to the image previews - and not the image passed through to Photoshop - unless you tell it otherwise?

[herbert]

Hi Geoff,

Just checking that you know that it only applys this sharpening to the image previews - and not the image passed through to Photoshop - unless you tell it otherwise?

Colin,

This warrants further explanation. Does this mean that the default settings are not applied but if you alter the sharpening then they do get passed through to Photoshop? Or is there an 'Apply sharpening' option?

I'm not intricately familiar with ACR since I go via Lightroom. In this case sharpening is applied only to raw images and not JPEG or TIFF at the same settings (25% @ radius 1). I believe these are passed through to Photoshop if you open the image from Lightroom even if you do not alter them.

Alex

[jprzybyla]

I would recommend that anyone who uses ACR or Lightroom read Real World Image Sharpening by Bruce Fraser and Jeff Schewe. In that book for sharpening they recommend determining if the image is high or low frequency, because each is sharpened differently. High frequency images (fine detail, such as a forest scene with lots of detail in small leaves) should be sharpened with a small Raduis (below 1.0) and higher than the default Detail setting. Low frequency images (smooth surfaces, such as skin in a portrait) should be sharpened with a higher Radius (above 1.0 but rarely above 2.0) with a lower than default Detail setting. There is no one setting that works for all images. After Capture Shapening there is Creative Shapening (sharpening areas of an image more than other areas), that can be done with adjustment brushes and masks. Output sharpening is the final sharpening, that is not done until the medium or usage of the image is determined because the Display, Web, and Print all have different sharpening needs.

[Colin Southern]

Colin,

This warrants further explanation. Does this mean that the default settings are not applied but if you alter the sharpening then they do get passed through to Photoshop? Or is there an 'Apply sharpening' option?

I'm not intricately familiar with ACR since I go via Lightroom. In this case sharpening is applied only to raw images and not JPEG or TIFF at the same settings (25% @ radius 1). I believe these are passed through to Photoshop if you open the image from Lightroom even if you do not alter them.

Alex

Hi Alex,

In ACR one simply needs to go into preferences (Ctrl+K) and see what it's set to. I think Adobe gave up forcing sharpening on images a while back after they were almost burned at the stake!

[Geoff F]

Hi Alex,

In ACR one simply needs to go into preferences (Ctrl+K) and see what it's set to. I think Adobe gave up forcing sharpening on images a while back after they were almost burned at the stake!

But, I think, with CS5 the default setting is All Images which automatically applies the sharpening. The other option of Preview Images Only which shows the effect of sharpening but doesn't actually apply it has to be chosen as the alternative.

Or was it the other way around and I have forgotten what I did.

Either way, certainly something worth checking.

I use All Images.

[herbert]

But, I think, with CS5 the default setting is All Images which automatically applies the sharpening. The other option of Preview Images Only which shows the effect of sharpening but doesn't actually apply it has to be chosen as the alternative.

Or was it the other way around and I have forgotten what I did.

Either way, certainly something worth checking.

I use All Images.

I've just had a look in my ACR preferences (CS 5) and it is set to apply sharpening to 'All images'. Since I cannot remember ever changing it then it is probably the default.

Lightroom doesn't have any such setting that I can find. So Colin, I have found a difference between Lightroom and ACR for you.

Alex

[Colin Southern]

I've just had a look in my ACR preferences (CS 5) and it is set to apply sharpening to 'All images'. Since I cannot remember ever changing it then it is probably the default.

Dunno to be honest -- mine was set the other way and I can't remember having to change it either - then again, I can't remember what I had for lunch 10 min after I've finished!