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Zoom in/Zoom out resolution – Did you know…..??
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When I sharpen a portrait image, I always look to the hair to see if it has possibly been oversharpened. Sometimes I satisfy myself that there are no jaggies, but when I zoom in or zoom out, this appearance can change.
Did you know that Photoshop only ‘resolves’ pixels to their proper appearance at certain numbers of Zoom, ie 25%, 50%, 100& etc. If you are zoomed at 100% and go up or down in increments, it goes down to 66.7%, then 50% then 33.3% then 25%. The pixels are only properly resolved at the proper numbers.
So view the image at 100% or 50% to see whether there are any ‘jaggies.’
brandyman wrote:
Did you know that Photoshop only ‘resolves’ pixels to their proper appearance at certain numbers of Zoom, ie 25%, 50%, 100& etc.
Yup :) But well worth pointing out.
I personally feel you should never sharpen at anything other than 100% anyway, as you should be examining the effects of sharpening at the true pixel representation.
Thanks for that Ross. That’s something I wasn’t aware of at all. Good tip.
Rob.
Another thing I only discovered – when working in ‘quick mask’ mode, you are painting on a mask using the paintbrush. The bits you are masking are shown in red (by default), and when you switch to standard mode, the red mask is replaced by the marching ants around the area you have not masked.
Try this – when in quick mask mode, press the tilde key (?) and your mask appears in black and white. Maybe a lot of people were already aware of that, but if (like me) you were not, then it is useful to know! When you see the mask in black and white you can then refine the mask using all sorts of things like filters, painting, blurring etc.Nice tips…! Thanks!
brandyman wrote:
when in quick mask mode, press the tilde key (?) and your mask appears in black and white.
which key do you mean? the tilde key on most UK/Irl layout keyboards is the one with the hash (#) and tilde (~) key… just to the left of Return (enter).
The one up the top left with the acute angle (?) is called the ‘Dead Key’… the one which when pressed does nothing, until the next key is pressed.
Im learning to use Photoshop so I’d like to know too… :)
On my keyboard it is the one at top left – above Tab and to the left of number 1. Let me know if it works!
brandyman wrote:
Another thing I only discovered – when working in ‘quick mask’ mode, you are painting on a mask using the paintbrush. The bits you are masking are shown in red (by default), and when you switch to standard mode, the red mask is replaced by the marching ants around the area you have not masked.
Try this – when in quick mask mode, press the tilde key (?) and your mask appears in black and white. Maybe a lot of people were already aware of that, but if (like me) you were not, then it is useful to know! When you see the mask in black and white you can then refine the mask using all sorts of things like filters, painting, blurring etc.You can change this behaviour if you Double Left Click on the ?Edit in Quick Mask Mode?, Button to reveal the ?Quick Mask Options?, interface. In the “Color Indicates” section you can choose between “Masked Areas” or “Selected Areas”.
brandyman wrote:
When I sharpen a portrait image, I always look to the hair to see if it has possibly been oversharpened. Sometimes I satisfy myself that there are no jaggies, but when I zoom in or zoom out, this appearance can change.
Did you know that Photoshop only ‘resolves’ pixels to their proper appearance at certain numbers of Zoom, ie 25%, 50%, 100& etc. If you are zoomed at 100% and go up or down in increments, it goes down to 66.7%, then 50% then 33.3% then 25%. The pixels are only properly resolved at the proper numbers.
So view the image at 100% or 50% to see whether there are any ‘jaggies.’
And another tip – view your image at 100% zoom if the final destination of your image is to be viewed on a monitor and view it at 50% zoom if the final output is going to be a print. Prints require less sharpening than images viewed on a monitor.
Thorsten wrote:
Prints require less sharpening than images viewed on a monitor.
Thats interesting to hear. I always sharpen shots MORE before going to print?
ciaran wrote:
Thats interesting to hear. I always sharpen shots MORE before going to print?
I was always of the view that you slightly over-sharpened before printing as well?
I’ve heard very good reports about a piece of software called QImage which is very good at both upsizing
images prior to print and also is smart about the level of sharpening appropriate to apply before printing.I’ve not used it but I plan to get it. I understand that the author has been very good over the years in updating
it and listens to feedback very keenly and he maintains it very well.I’ve found that I usually have to sharpen when *downsizing* to web viewing size. With regards to how much
sharpening is needed in print it depends a lot on the original size of the image and the target DPI and
dimensions of the target print. Some labs prefer you don’t sharpen and they handle it within their RIP software.
If you are printing yourself using inkjet,etc then you may have to experiment but I do believe that
Qimage is well worth taking a look at if you are interested in squeezing the best performance in terms
of getting the image optimized to print.–Ian
WRT to sharpening before printing, it’s a bad idea if you’re getting lightjet prints off a Fuji Frontier thing or similar (like what Photobox use). I think something in their processing routines involves another pass of USM so it’s added onto any sharpening you’ve already done and can look utterly gross. I generally send Photobox only absolutely minimally sharpened, if at all, files, and they come back nice, but the ones I tried first sharpened to taste on the monitor were abysmally oversharpened and artefacty.
ciaran wrote:
Thorsten wrote:
Prints require less sharpening than images viewed on a monitor.
Thats interesting to hear. I always sharpen shots MORE before going to print?
Me too, It normally looks a bit “Rough” on screen after sharpening, before printing.
Si
Ian – I use QImage for all my home printing and occasionally for lab printing purposes too – it’s got excellent interpolation algorithms which work really well. The interface is a bit clunky and takes a bit of getting used to, but I think it’s a great piece of software and certainly much better value for money than a full-featured RIP.
The points made by Ian and Steve above re. lab prints are very valid and important ones. I think the best thing is to submit some test prints at varying degrees of sharpenning and decide for yourself what looks best. I should have clarified in my earlier post when I was referring to prints, I meant lab prints as opposed to inkjet prints. It’s true that inkjet prints do require more sharpening because of the tendency of the ink to diffuse through the paper thereby introducing some softness. Apologies, I didn’t mean to mislead anyone. I normally let QImage worry about this!
As for the logic of viewing at 50% for print sharpening – at that magnification Photoshop is doing pixel dithering — not unlike a printer will do — to show the image on screen. At 50% there are four image pixels dithered to make one screen pixel.
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