Usual problem

I've done my usual trick of posting a competition entry late at night only to find on inspecting it the following morning that it doesn't really properly reflect the full size original.

Still haven't got to the bottom of this. My weekly comp entry this week was done using JR's method as outlined here link - resizing to 1200 pixels width then sharpening (though I did alter the amounts to get the desired output - I think it was around 70%/Radius 1.3/Threshold 1). The result was this:




This morning I tried to do it the way Daniel Bridge favours (halving a sharpened full size image to 2000 pixels width then applying circa 65/0.8/0 then halving again and applying circa 55/0.8/0). I got this:




To my mind the latter looks better (even though it's smaller - and in the past I've had more problems the smaller I've got) - and closer to (though still not as good as) the sharpened original on full screen. (I should have waited and entered this in the comp - not the one I did.) To my eye even the colours are slightly better in the second shot - and I don't think it's ovesharpened (though I'm often - rightly, too - criticised for this). Does anyone else have any thoughts on this?

Perhaps I'm seeing things?!

But I think there is a difference - check out the detail on the prawns legs & the lamp base. Also the colour is - if my eyes aren't completetly misreading things - very slightly lighter in the second (though this is much harder to see, admittedly) - check the prawns and the flat bread.

The second image looks brighter too

I doubt this affect how the image will be judged in any way, though

The 2nd shot is lighter. It is evident in the whole shot but the giveaway is that I can see detail in the shadows where I cannot in the 1st image.

Well I'm not sure i can tell any difference, though one picture is 1200 px wide and the other only 1000, wont that make a difference?

They both appear just as bright for me but there is a bit more contrast in the second photo, you can see that with the shrimps and the crabs look sharper.

I'd say the second image is marginally better than the first as there is slightly more detail in the shrimps and crabs, as Stefan says.
david

Thanks for the feedback, all.

I've still not got to the bottom of this issue. In this case, the second re-sized version is pretty close to my original sharpened one on a full screen (which produces the optimum viewing results on the equipment I am using - a 13.3" laptop). However, with other photos - such as my entry to the bricks competition last week - I find I can't re-size without a loss in image quality, and as a result I sometimes end up over-doing the sharpening to try to capture the detail in the original.

Has anyone else experienced similar problems?

SteveT - the images here have both been re-sized by the forum engine, so I don't think the fact that one is 1200 wide & the other 1000 is siginicant. Though it would be a different matter if you opened up the larger images in another window. However, I find that once again the second shot is better then too - although normally my experience has been that larger image size results in a better quality picture. So I guess this goes to show that the latter method is perhaps preferable - that is unless I'm getting the former wrong (though it is quite straightforward, so I don't really see what I might be getting wrong).

Are you using unsharp mask on a full pixel/size image?

I never do this.

Mike

There is no point trying to compare two images of different original sizes that the forum software then resizes differently.

Looking at the originals, the second looks sharper, certainly, but it's smaller, so you'd expect it to, so again, hard to compare.

Mike - Yes I apply USM to a full size jpeg when I've finished working on it in PP. For me, this is the way I see the full potential of the shot - on my computer on full screen. And when I re-size, I am trying to capture the quality of this original. And judging by my experience here, I think I'm right to do this - as when I sharpened the original after resizing above the result was worse.

Chris - I understand that it is difficult to compare when there are variables, such as image size. However, contrary what one would expect, in my recent experience (since I switched laptops in the summer) larger files look sharper and more detailed when I've resized them. In particular I have problems re-sizing images to under 1000 pixels width. I find I can retain decent quality in resizing down to around 1200-1000 pixels, but then under that the image quality deteriorates noticeably - both when I view it on my computer AND when it is uploaded and resized on the forum.

There's a difference between actual sharpness and apparent sharpness.

Inevitably, making an image smaller removes detail, if the detail is there to start with. So a bigger image, properly sharpened, may look more detailed than a smaller one, also properly sharpened, simply because it is.

Against that, there's the increase in apparent sharpness that you get by simply making lines and other details narrower, which is what happens when you resize down.

So there are conflicting effects, and they're not always entirely predictable.

Getting to the bottom of whatever's causing this will be the key to it for you, I think.

There shouldn't be any sudden change in quality at any arbitrary size, if the software you're using is up to the job.

It's a mistake, though, to let the forum do any resizing at all. Resizing once, sharpening carefully for that size, and then letting the forum scale it again is bound to give you a worse result than sizing and sharpening for the 800px max.

Unless of course, you aren't bothered that the forum scaling makes it worse, and your intention is for people to click on the image and see it in a different tab at its original size. That's a valid approach too, since it at least gives us the opportunity to see it in all its bigger glory. I quite like that, although not everyone will click to open a new tab.

Personally I always have the PSD file at full size and then I will convert the file for whatever purpose it is intended. SO I would not sharpen the PSD file as I can see no point.

To use here probably convert to sRGB, resize, unsharp save as JPEG.

For printing I have taken to resize to target print size, unsharp, print

I think Mattmatic suggested to me it was better to keep a master PSD file and the always work from that to whatever target use was planned (if the grammar there makes sense). So for one image I may have 3 or more JPEG files of different sizes all processed from the master PSD.

Mike

Chris - I've been using PSE to re-size of late. Funnily enough, on my old computer I used to just do a resize in Microsoft Office Picture Manager, with no adjustments. I guess this is pretty crude, but I never noticed any particular loss of image quality back then. When I did this on my new computer, I noticed substantial degradation. (I suppose this has something to do with the higher quality screen on my new laptop - though I didn't expect the difference to be so dramatic. Could be the size of screen too - this one's 13.3" as opposed to my old 17"). I didn't get around this until I started using the method outlined above as suggested by Daniel Bridge. As I said this works for me down to about 1000 pixels.

Mike - I think there's perhaps some misunderstanding. I also have a PSD file saved (at least I have started doing this of late). However, at the time of creating this I also save a sharpened jpeg, as I find this indicates the full potential of the image as viewed on my computer which I aim to replicate in re-sizing. But the results still seem better if I sharpen before resizing by half, then sharpening again etc.

What I always do is save for Web and then you can keep the PSD as it is and he does all the necessary things for you.
Resizing, Colour space, sharpening, optimizing (trying to make the file smaller), etc.