Sharpening in digital?

[feldy]

Hi guys - have recently had an email from a photo reseller promoting a seminar on sharpening, but couldn't make it... a couple of interesting questions:

- the email referred to some problems/issues in Lightroom with respect to sharpening - does anyone know what they were/are?
- someone once told me that they sharpen all pictures taken digitally - presumably because they felt at the time [several years ago] that digital maybe wasn't quite up to traditional film...

... do you tend to sharpen purely on a case-by-case basis, or do you agree with that person that most shots [almost by default] need to have sharpening applied?

A

Ps I realise the obvious answer is 'it depends on the lens' but I still think it's an interesting general question!!

[surenj]

All digital pictures (RAW) needs sharpening. JPEGs have this done already.

[Murray Foote]

The standard approach to sharpening (from Fraser and Schewe) is a three-step process with capture sharpening, creative sharpening and output sharpening.

Digital passed 35mm film a long time ago, it has nothing to do with that. All digital and scanned analogue images benefit from sharpening.

Capture sharpening is useful because images come from the camera somewhat blurred, due mainly I think to the anti-aliasing filter. The optimal amount here is subtle and not necessarily something you can determine by eye.

Creative sharpening is where you optimise the image by eye. Some images require noise reduction first, which may be overall noise reduction or regional (eg just for background areas). Then overall sharpening is OK for some images whereas many benefit from regional sharpening. A few images, which are noisy but where overall noise reduction loses too much detail, may not benefit from sharpening here though there may still be a place for regional noise reduction.

Output sharpening is again something you can't reliably do by eye. Sharpening for matte papers, in particular, requires sharpening to a level that looks oversharpened on screen due to the effects of the coarse paper surface.

Sharpening in Lightroom is useful and sufficient for many images but not nearly as powerful as what you can do in Photoshop. For some images this can make a big difference. Lightroom has some regional sharpening ability but not nearly as much as Photoshop and you can control haloes in Photoshop independently of overall sharpening.

[Mr Darcy]

Because of the nature of the digital sensor (all of them!) all digital images need some sharpening. Straight out of the sensor, all images are slightly soft. Depending on your settings, JPEGs are sharpened when they are created in camera. You can turn this off on Nikons. I assume you can on other brands as well.

RAW files are the direct sensor data, more or less, so RAW images will need some sharpening. If you are using Nikon and Capture NX, the amount of sharpening set in camera is applied automatically. Lightroom3 applies some sharpening automatically. You can increase, or decrease, this on an image by image basis. A romantic shot of a pretty girl requires much less sharpening than a gnarly tree where you want to show every twist of the grain.

LR3 has dramatically improved their sharpening algorithms over earlier versions. The information you are getting may be based on the earlier versions, and the person is either unaware of the improvements, or he is glossing over them because he is trying to sell you something. You can download an LR3 trial & try it for yourself. You can also download a trial of Sharpen EfexPro & see if it does a better job for you. I have both & really can't be bothered with the sharpening in SharpenEfexPro as I don't see a marked improvement over what LR gives me native.

[feldy]

thanks guys for the thoughtful responses so far...

Digital passed 35mm film a long time ago, it has nothing to do with that. All digital and scanned analogue images benefit from sharpening.

Capture sharpening is useful because images come from the camera somewhat blurred, due mainly I think to the anti-aliasing filter. The optimal amount here is subtle and not necessarily something you can determine by eye.

Murray - just a quick one: seems to be a bit of a contradiction in the above - you say: 'it has nothing to do with that [ie digital]" but you then say: "Capture sharpening is useful because images come from the camera somewhat blurred, due mainly I think to the anti-aliasing filter" - isn't this purely a digital thing, ie as film doesn't, by definition, have anti-aliasing??



A

[Murray Foote]

thanks guys for the thoughtful responses so far...

Digital passed 35mm film a long time ago, it has nothing to do with that. All digital and scanned analogue images benefit from sharpening.
Capture sharpening is useful because images come from the camera somewhat blurred, due mainly I think to the anti-aliasing filter. The optimal amount here is subtle and not necessarily something you can determine by eye.

Murray - just a quick one: seems to be a bit of a contradiction in the above - you say: 'it has nothing to do with that [ie digital]" but you then say: "Capture sharpening is useful because images come from the camera somewhat blurred, due mainly I think to the anti-aliasing filter" - isn't this purely a digital thing, ie as film doesn't, by definition, have anti-aliasing??
A

Rephrasing my first sentence: "Digital passed 35mm film a long time ago so sharpening digital images has nothing to do with their quality as compared to 35mm film".

These days, if you are shooting film, it's relatively unlikely that you are printing black and white or just showing slides. You are likely to be scanning, or worse, accepting probably low quality scans that come with the film. Scans are digital images that benefit from sharpening in the same way as images from digital cameras, though the optimal amount of capture sharpening will be different.

Greg makes a good point concerning in-camera sharpening. In general you should turn it off because it is likely to degrade your image and Lightroom or Photoshop can do it much better.

I don't agree with Greg entirely on Lightroom 3 sharpening, though. Sharpening in Lightroom 1 and 2 was virtually useless and Lightroom 3 is much improved. You can use it on all images if you want and it will be OK. However, IMHO it is adequate rather than industrial strength. Jeff Schewe himself says it doesn't incorporate capture sharpening. You can get both more subtle and stronger effects in Photoshop. There are many ways of doing this including High Pass, Smart Sharpen and as a second step, using layer style blending options to reduce highlights/haloes (from double-clicking a layer). Utilities can be useful as well; I use PK Sharpener.

[feldy]

makes sense - cheers Murray

A

[Matt. K]

Take care you don't over-sharpen your images. This is one of the most common mistakes made by amatuer photographers and even by many professionals. To see how crappy this can look just go to your local newsagency and flick through the latest gardening and house beautiful magazines. Most of the images will have been over-sharpened and it makes the images look overly fussy with detail and unnatural. Better to underdo than overdo.

[PiroStitch]

Very important point made by Matt! I cringe everytime I see an image that's been oversharpened (my own included!)

Other alternative is to buy a camera that has not AA filter

[feldy]

so bottom line: turn off 'auto' sharpen in the camera, and do it all 'post' shoot in P/shop, sounds like the way to go...

[PiroStitch]

Indeed. If you shoot RAW, the in-camera sharpening will be negated anyway.

What I've found sometimes is that I don't need LR/Photoshop sharpening at all. Not all images need to be sharpened, usually it's a case by case for me.

[Murray Foote]

This raises the question "What is oversharpening?". You can see it in unnecessary detail, often with lots of small specular highlights and you can see it as sharpening haloes, light lines around objects. Because much of what passes for sharpening is in effect intensification of local contrast, you can also see oversharpening affecting the contrast characteristics of an image in undesirable ways.

If you are using overall sharpening, you have to lower the level of sharpening to counter this. If you have a more customised approach to sharpening in Photoshop, you can control these artifacts independently of the general level of sharpening.

[biggerry]

... do you tend to sharpen purely on a case-by-case basis, or do you agree with that person that most shots [almost by default] need to have sharpening applied?

depends..

for teh web, always, progressive sharpenign all the way

in camera sharpening is set to some form of sharpening then its a case by case situation in PP.

so bottom line: turn off 'auto' sharpen in the camera, and do it all 'post' shoot in P/shop, sounds like the way to go...

there is no bottom line. That creates an extra step in PP that could well be achieved before the file even leaves the camera, unless the PP sharpening significantly improves or does more than what the camera does I do not see the merit in this.

[ATJ]

so bottom line: turn off 'auto' sharpen in the camera, and do it all 'post' shoot in P/shop, sounds like the way to go...

For me, sharpening in the camera is somewhat irrelevant (and I trust it is for you, too).

I shoot raw and I use Lightroom for my post processing. Sharpening in the camera has no impact on the image stored in the raw file (other than the embedded JPEG). All that happens is there will be some bits turned on in the raw file that say what camera settings were in effect at the time of shooting. If I used Nikon Capture NX2, it would read those settings and apply them when converting the raw image. Lightroom does not (other than white balance as far as I am aware) so the sharpening setting in the camera will have no effect.

I believe Photoshop is the same, so if you are shooting raw and processing in Photoshop, turning sharpening on or off in the camera should have no effect.