Just curious what some of you people have found the best way to sharpen your photos for reducing the photo's size to put on the web. Not necessarily for this site but for a website like bludomain. They have a tutorial to resize them but it doesn't say anything about sharpening. For another site I post photos to, I use Unsharp mask set to : amount 100%/radius .4/threshold 2
It look OK but those photos have a different size than what I am allowed to post on my own website. Here is a link models, maybe NSFW
In DPP I set sharpness to 3 or 4 before converting/saving RAW images...
In PS I use 0 threshold all the time...habit more than any other reason...
1. images with highly defined lines, like tree limbs, I use the more modest sharpening combo...higher % (amount) and lower radius...the opposite, (lower amount/higher rad.) is too sharp and will create the shadow abberation around sharp lines...
2. images with few defined lines, like facial portrait, you can use the more aggressive combo, lower % (amount) and higher radius...the opposite (#1 above) will have much less effect...which may be preferred for a softer effect...
You can test this yourself by comparing 500%/.2/0 vs 200/.5/0 on both types of images to see the results that you prefer...I rarely exceed 500% and .5 radius
3. You typically have to use usm AFTER the final resizing...tho sometimes I do USM 1st in the TIFF file and again after converting to JPEG...
4. You don't have to sharpen as much for the web as you would for prints...
Most websites like this would PREFER a horizontal size limit of 800dpi, but many posters ignore this...forcing viewers to slide b/f on the horizontal scroll bar...oh well...
That article is a bit dated. There is no longer any benefit to multi-step reduction if you use bicubic-sharper in CS3+ (This did make a big difference in older versions of Photoshop, but was a PITA).
My approach is as follows:
1. No sharpening in Raw converter.
2. Layer based capture sharpening applied to midtones only. I set up an action for this, and the details are in Bruce Frasers book on image sharpening.
3. I resize to 800px wide using bicubic sharper (CS3)
4. I then apply USM at (typically) 120-0.3-0
Unless I am mistaken you have misread it. There is a single resize stage using Fit Image - it is the sharpening that is multi stage. (and he may not even have Photoshop anyway let alone CS3+ )
paulhodson wrote:
Unless I am mistaken you have misread it. There is a single resize stage using Fit Image - it is the sharpening that is multi stage. (and he may not even have Photoshop anyway let alone CS3+ )
Yes he wasn't applying multi-step reduction, but commented that reduction in one step significantly reduces sharpness. I suspect the multi-pass sharpening is somehow designed to compensate. If you use bicubic sharper and then 3 passes of sharpening, you'll probably overcook it. He refers to CS2, when the advice about reducing in one step was valid.
paulhodson wrote:
Unless I am mistaken you have misread it. There is a single resize stage using Fit Image - it is the sharpening that is multi stage. (and he may not even have Photoshop anyway let alone CS3+ )
That's how I read it as well.
He is actually applying sharpening 4 times during the action, first a slight USM before resizing down to fit in a 600x600 image size, then 3 consecutive times to finish.
He's using multiple layers and blending modes to avoid sharpening certain parts of the image. Not sure how good the action is, plan on trying it when I get a minute.
I've struggled with this as well ... I have a lot of large captures, and reducing to web is a challenge. Lately I've been resizing with bicubic normal (not sharper), the using Smart Sharpen at 200%, radius 0.2. Sometimes I bump that up to .03, and sometimes I drop the % based on how it looks.
conceptually the first part of his action is similar to Bruce Fraser's approach (use blending modes to limit sharpening to mid tones). I'll dig up Bruce's book soon and check parameters to see how they compare. As noted above you should make sure you use the bicubic option.
Since sharpening is subjective, depending on photo content, I like to do it visually.
After resizing the image with bicubic (smooth gradients) I apply USM = 500%, .2.,0 then run Fade > USM, changing mode to luminosity.
The Fade USM (luminosity) step does two things. First it applies the sharpening to the Luminosity channel of the image, even though the image is being edited in RGB mode. But more importantly in terms of setting USM to the image the Fade step allows me to apply the high amount/small radius sharpening in any amount from 0% to 100% using the opacity slider. 0% = no sharpening. For most portrait subjects I find 60-70% looks best. If the photo is a scenic then it will often look better with a higher percentage. But in all cases by sliding back and forth from 0 to 100% I can find the happy medium which pleases my eye. I've compared that technique learned years ago from a Dan Margulis article with resizing with Bi-cubic (Sharper) and find that I prefer things a bit sharper in most cases that Bi-cubic (Sharper) produces.
I will also selectively over-sharpen images with fur and feathers to enhance the detail by creating a normally sharpened layer and a second over-sharpened layer to enhance the texture of the fur which I blend in by eye with a mask.
Use a good resize algorithm like Lanczos or SinC in stead of BiCubic. I know this is not a popular choice because of the inability of Photoshop to use any other algorithm except the three included ones natively, but they all stink outside their intended uses...!
Nearest Neighbour is for squarely pixelized integral value upsampling, BiLinear is for smooth and geometrically good (from a pure mathematical point of view) but soft downsampling, and Bicubic.... Well I don't really know what it's for. It is from some points of view slightly better than BiLinear, but still not a good algorithm for two-dimensional matrix resampling. It seems to be purely (machine-time) performance oriented in the Adobe version of it.
If real detail retention is as important as apparent "sharpness" (edge acuity) then you have to go outside the PS "box". The only way to make Photoshop do a geometrically and mathematically "good" resize is to do it in LAB colour-space, or set the "mix RGB with Gamma:" to 1.00 in the "Colour Settings" menu. Otherwise Photoshop will attempt to do linear computations on your logarithmic RGB-space, and this really kills detail... Unfortunately resetting the "mix RGB with Gamma" will cause problems in most other areas as PS is "after-corrected" to do most of its transformations and filter-work in a Gamma-corrected space when working in RGB. This is really poor programming.
The examples that has been given to you above are all good, so if you like the result of any of them, use it! I just wish that you wouldn't have to resort various work-arounds to "cheat the program" when doing a simple task like this.
Personally I've only found one way to make Photoshop do a visually pleasing and detailed downsize - oversharpen the large original (like - LOTS and LOTS! The normal "sharpen" or "sharpen more" will normally do just fine - depending on the resampling rate you will use of course, and then downsample with BiCubic Normal. This will counteract the strange behaviour that the BiCubic shows (in Adobe's interpretation of it)...
Sorry for the rant, but I really think it's kind of strange (and irritating) that Adobe still after 13 complete version updates or so of this program still can't do a simple thing like a resampling right...
Below I included an example of the differences between algorithms that I originally made for a local forum. Upper left is the "original" 100%, the others are downsampled to an uneven value to make the differences more apparent (an even 50% or 33% is easier on the computation). I believe the resampling was set to 42-44% or something. I then upsampled the results 2:1 with "nearest neighbour" to make the difference at pixel level easier to see. The BiCubic downsampling was done in Photoshop (BiCubic "sharper"), and the Laczos was made externally to PS.
NO sharpening has been applied to any of the samples!
(and he may not even have Photoshop anyway let alone CS3+ 
)