Confused about web posting

[mblumer]

I'm sorry if this appears to be a moronic question but I am confused.  I shoot pictures with two cameras.  Both are full-frame 35mm.  One is a Nikon D3 at 12.5 mp.  The other, and the one I use most often, is a Leica M9 at 18 mp.  There is a forum where I like to display my pictures that limits pictures to 960 pixel width.  When I post to that site my pictures are seriously unsharp and dull.  I usually prep my pictures in either LR 3 or CS5.  What pixel resolution should I be using and what is the best method to reduce the pictures to this maximum dimension but to retain maximum picture quality?  When I go to print (I have an Epson 3880) I export at 360 ppi.  I get excellent sharpness, contrast and color depth.  I would have thought that posting to the web would be easier but I'm having a heck of a time.

Thanks for your help.

Mark Blumer

[DarkPenguin]

Have you tried doing a lightroom export with screen sharpening set to standard?  Resolution shouldn't matter so go with defaults.

[mblumer]

Have you tried doing a lightroom export with screen sharpening set to standard?  Resolution shouldn't matter so go with defaults.

Thank you for what should have been an obvious solution!  I had previously unchecked the export sharpening box.  I forgot to re-check that option when exporting for screen.

Mark Blumer

[BobFisher]

Dull won't necessarily be affected by sharpening.  That sounds more like it might be a profile issue.  Resolution is irrelevant for web posting.  

Most browsers aren't colour managed.  If you post an image that's untagged or tagged with AdobeRGB or ProPhotoRGB, it'll look dull, washed out.  To ensure the best colour rendition for people viewing on the web, make sure you're either doing a Convert to Profile and using sRGB in CS5 or tagging with sRGB in the LR Export dialogue.

[ckimmerle]

Resolution is irrelevant for web posting.

That's not necessarily true. If sites restrict images to a certain size, they may be using a simple script to resample images to the appropriate size. If the submitted files are much larger than the display resolution, they can look quite bad. That is what I am thinking has happened in this case, at least partially. It's usually best to try and upload photos as close to the max size as possible.

As for looking dull, it may very well be, as stated earlier, that it's a profile issue. AdobeRGB images tend to lose some color saturation when put on the web. It's best to be sure and convert to sRGB before uploading.

[BobFisher]

Pixel resolution is irrelevant for web posting.  Doesn't matter whether it's 72ppi, 96ppi or 105894785604ppi.  Some websites will resize images if the submitted image is too large.  Flicker is famous for taking a good quality image and turning it into crap in their conversion process.  In that case; however, it's the pixel dimension that's the issue, not the resolution.

This image is at 1000ppi, http://www.rf-photography.ca/Windows-1000.jpg
This image is at 72ppi, http://www.rf-photography.ca/Windows-1.jpg

Both at 640x426.  The two appear identical in a browser window.  They'll print very differently, but on the web, no difference.

[ckimmerle]

You're right in that resolution, given identical file sizes, is not relevant. That's why I said it was "not necessarily true". However, the OP was, from my experience, having issues with overall file size, of which resolution is part. If you look back at the OP , you'll see that he referenced printing at 360 ppi and that, at the resolution, everything looked great in a print. In this case, your response saying that "Pixel resolution is irrelevant" is misleading as it indicates that a change in ppi would be irrelevant. However, if he had resampled to 72ppi, he would have seen much better results as the overall file size would have been much closer to that allowed by the host gallery.

THAT was my point.

FYI: the RF-Photography link on you footer is addressed incorrectly. There is a dash after the WWW rather than the required period. Just thought you'd like to know.

[BobFisher]

If you're going to quote me, please do it correctly.  What I said was pixel resolution is irrelevant for web posting.  Of course it makes a difference for printing.  Resampling before posting, to change file size, is an entirely different matter as well.  Yes, resampling will cause a change in the quality of the image.  Again, that has nothing to do with pixel resolution on the web.  

Given that the OP knows the pixel dimension limits of the site he's posting too, I assumed - perhaps incorrectly - that he would be posting within those file sizes.  If there's another limitation for overall file size, then even if the image is posted within the required dimensions, the site may be applying further compression which will cause a reduction in quality.  But whether the image is posted at 72ppi or any other number is irrelevant to how it will appear in a browser.

Thanks for the heads up on my web link.  Not sure how/when that got messed up.

[fredjeang]

What Bob said is correct.
If you Know the site that will just work.

But it does not mean you should not doing the downsampling yourself.
Why?

Simply because a script can be involved.
The script could be a limitation in images weight, automatically reduced by the site with deplorable results.
This is difficult to verify, but what you can try is sending the pic to the max dimensions allowed but at 72.

I bet that your image will be perfect.