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Keeping images sharp ?
#1

I find my photos are too large to upload here, so I have either to upload them to a third party site and link them, or resize them in post editing, but saving a resized picture loses the sharpness.. Which is best to see here ?

Canon EOS 650D with 18-55 kit lens/ 75-300 zoom/ 100-400 zoom
https://www.flickr.com/photos/125137869@N08/
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#2

What software Johnny, surprised it "Unsharpens". This pic,

http://www.shuttertalk.com/forums/Thread...9#pid95819

Was originally 11Mb, reduced to, 756Kb, for uploading, lost nothing really. Will upload the original, and link it, if you wish to compare. Cheers. Ed.


To each his own!
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#3

Johny, if you wish to take charge of the down-sizing, rather than letting various browsers and/or photo-hosting web sites do the job for you, you could follow closely the example given by Shuttertalk.

Notice that, whenever someone posts a photo that is too large for these forums, a message along the bottom edge of the image shows that it has been down-sized to 916 pixels wide. This is so that the image will download quickly and be viewed at 100% (1 image pixel = 1 screen pixel).

To me, 900 pixels seems a good size, as it fits within the width of the windows of most Internet/Web Site software, and the screens of desktop PCs, laptops and tablets.

So I make a copy of the full-size image file, and apply the re-sampling feature of editing software - e.g. using "bicubic" in PaintShop Pro or PhotoShop Elements, at fixed aspect ratio - to downsize the width to 900 pixels. Then, viewing the resulting image at its full size (100%), sharpen it if necessary - e.g. unsharp mask at strength=100, pixels=0.33, clipping/threshold=0. Then save the JPEG file - set at best quality (i.e. lowest compression) - ready for uploading to the web.

This seems to work - e.g. does this look sharp? - it is another photo of Wrest Park Mansion:

   

Cheers.
Philip
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#4

I hear what you are saying and have followed the resizing that was mentioned a few weeks ago. I use P.S.P X6 but every time a copy of an image is saved as a jpeg a tiny amount of detail is lost.

Canon EOS 650D with 18-55 kit lens/ 75-300 zoom/ 100-400 zoom
https://www.flickr.com/photos/125137869@N08/
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#5

(Jun 23, 2014, 16:31)johnytrout Wrote:  I find my photos are too large to upload here, so I have either to upload them to a third party site and link them, or resize them in post editing, but saving a resized picture loses the sharpness.. Which is best to see here ?

Johnny, I wouldn't worry too much about this. Folks will be looking at your images on all types and sizes of monitors. You will never be able to match your image to all of them. Some will have high-end IPS monitors that are often used by pro photographers for all their work, whereas others will be viewing your images on laptop screens which are most often TN monitors, so the quality of what they see will vary considerably because the colour gamut which each monitor is capable of displaying will also vary. I usually size my images for anywhere from 500 to 1000 pixels on the longest side. This seems to be sufficient for all the images that I post. When I do the conversion in Lightroom from a raw or tiff image to a jpeg, I also sharpen for display at the same time and this seems to yield acceptable results.

Hope this helps.

WesternGuy
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#6

(Jun 24, 2014, 08:59)johnytrout Wrote:  I hear what you are saying and have followed the resizing that was mentioned a few weeks ago. I use P.S.P X6 but every time a copy of an image is saved as a jpeg a tiny amount of detail is lost.

Technically that is true but, in practice, it makes little if any visible difference to the image quality if -
1. The saving is done in the same editing session.
2. The JPEG options are set to high quality / low compression.

So, I ask again - does the down-sized Wrest Park image in Post #3 here look sharp? (It is sharp on my desktop, laptop and Android tablet screens.)

Following point 1, I work only with JPEG files (not raw) - so the original camera JPEG was copied, opened in PSP X6, tweaked to my liking, and saved using Save As to make a new JPEG with a new name. This new file was then down-sized as described in Post #3, then saved as another new JPEG with a new name, for uploading to Shuttertalk. Following point 2, the JPEG Options were set to the lowest compression level, although 10% would probably have been good enough.

As a matter of interest, I opened the upload file again in PSP X6, saved it with a new name, closed it, opened the new file, saved it with a new name, etc. etc., 10 times altogether to get this one:

   

Does it look worse than the one in Post #3?

   

Cheers.
Philip
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#7

Yes it still looks sharp to me.
Well ............ I live and learn,
I have two P.S. Pro's, 7 and X6 and I never knew about the compression on jpegs.
On psp7, the compression is set to 15 and on the X6 it is 10
So what you are saying is they need to be lower ........ like 5 or less ???

Canon EOS 650D with 18-55 kit lens/ 75-300 zoom/ 100-400 zoom
https://www.flickr.com/photos/125137869@N08/
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#8

(Jun 24, 2014, 16:22)johnytrout Wrote:  Yes it still looks sharp to me.
Well ............ I live and learn,
I have two P.S. Pro's, 7 and X6 and I never knew about the compression on jpegs.
On psp7, the compression is set to 15 and on the X6 it is 10
So what you are saying is they need to be lower ........ like 5 or less ???
Edit ...
Thanks for your advice, I have now set them both as you have in yours tyvm

Canon EOS 650D with 18-55 kit lens/ 75-300 zoom/ 100-400 zoom
https://www.flickr.com/photos/125137869@N08/
Reply
#9

(Jun 24, 2014, 16:22)johnytrout Wrote:  Yes it still looks sharp to me.
Well ............ I live and learn,
I have two P.S. Pro's, 7 and X6 and I never knew about the compression on jpegs.
On psp7, the compression is set to 15 and on the X6 it is 10
So what you are saying is they need to be lower ........ like 5 or less ???

It does not need to be as low as in the examples here, unless perhaps the same file is being opened/edited/saved/closed many times.

It is unlikely that any quality drop would be apparent in normal viewing if the file has been edited then saved only once or twice at a compression level of 10-15%.

(But, of course, there might be other factors in the image processing that are affecting image sharpness.)

Cheers.
Philip
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#10

(Jun 25, 2014, 06:26)MrB Wrote:  
(Jun 24, 2014, 16:22)johnytrout Wrote:  Yes it still looks sharp to me.
Well ............ I live and learn,
I have two P.S. Pro's, 7 and X6 and I never knew about the compression on jpegs.
On psp7, the compression is set to 15 and on the X6 it is 10
So what you are saying is they need to be lower ........ like 5 or less ???

It does not need to be as low as in the examples here, unless perhaps the same file is being opened/edited/saved/closed many times.

It is unlikely that any quality drop would be apparent in normal viewing if the file has been edited then saved only once or twice at a compression level of 10-15%.

(But, of course, there might be other factors in the image processing that are affecting image sharpness.)

Cheers.
Philip

Hi Philip,

Congratulations in explaining a topic which can be rather complex, in a manner that was easy to understand. PhotoPlus X5 has a very similar operational procedure, and I also go through the same process as yourself. Eg, save as under a differing name, then exporting to a different directory & file, at reduced resolution with yet another name. Frankly, as I see it, it's the most logical way of working.

Have you ever considered the possibility of teaching this stuff at say evening classes? You ought to, your explanations are concise and very logical. As are EdMac's.

Best regards.

Phil.
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#11

Thank you, Phil.

To be helpful, I do try to make explanations concise and logical, so it is encouraging to have them described as such. As a relative novice, I wouldn't consider teaching this stuff but, when writing an explanation, I try to put myself in the position of someone learning something new. That is not difficult as I am learning new stuff all the time, having taken up digital photography seriously only a couple of years ago, since I retired - from school teaching!

Cheers.
Philip
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