How to improve definition of photos posted on website

[Rupert67]

As a member of our local U3A I am the unofficial official photographer at numerous outings to places of interest. I use my 5DIII and one or other of my 'L' lenses, more recently my EF 24-105 mm f/4.0L IS II USM, with the images (shot in RAW) processed and saved as jpegs.

My saved pictures are typically 5760 pixels on the long edge and I usually choose a file size between 2.0MB and 2.5MB, although sometimes I'll save them as larger files if they're in portrait format - for some reason it makes for better definition when imported to a PowerPoint presentation.

We have a local website and I always submit a selection of pictures to the co-ordinator for posting on the site, so that those who were present at the time can enjoy some memories of the day. To this end I always reduce the jpeg images to 1000 pixels in width and between 1.5KB and 2.0KB in file size. I send them across by email in a zipped folder and subsequently they appear on the site.

What I've noticed, however, is that the pictures lack sharpness when viewed on the web page, when compared with the same reduced images viewed on my computer screen. Why should this be and does anybody have any advice about a more appropriate image size to submit for subsequent posting, which might improve the look of the resultant image when viewed on the web page?

 

[droj]

Since your figures are unlikely, do you mean 1.5Mb and 2.0Mb? If so, that's far too big and I'd guess that someone is re-saving them with what might seem to be a large degree of jpg compression.

 

[Rupert67]

Since your figures are unlikely, do you mean 1.5Mb and 2.0Mb? If so, that's far too big and I'd guess that someone is re-saving them with what might seem to be a large degree of jpg compression.

Sorry droj, I meant 150KB to 200KB - I'm aware that 1.5MB upwards is usually too large for websites.

 

[sirch]

You probably need to talk to whoever uploads them and find out how they are uplaoded and to where; there could be further automatic compression going on server-side. You could also try downloading the image from the website (right cliick the image and select "save image as") then compare the saved image with the one you compressed, if the size is different then it has been compressed further

 

[Rupert67]

You probably need to talk to whoever uploads them and find out how they are uplaoded and to where; there could be further automatic compression going on server-side. You could also try downloading the image from the website (right cliick the image and select "save image as") then compare the saved image with the one you compressed, if the size is different then it has been compressed further

The plot thickens!

I downloaded one of the pictures from the website as you suggested, to find that it's 900 x 600 and 121 KB (my original reduced version was 1000 x 667 and 143 KB). Not only that but, viewed as they appear on my computer screen, I laid a 12" ruler along the long edge and found that my original reduced image measures 265mm wide, the same picture viewed on the website measures 298mm wide but - and this is the odd thing - the website version I downloaded measures 239mm wide.

Clearly there is additional compression going on here, so could I offset the effect this has on my images by saving them as 'heavier' files, i.e. the same dimensions - say, 1000 px wide - but possibly upwards of 500KB or more? Or should I be looking at the sharpening phase of my image processing, if the pictures are intended for the website?

 

[Chaz Photos]

When resizing them are you then sharpening? as this is always the last thing you do, Facebook give this info

• Resize your photo to one of the following supported sizes:
  • Regular photos: 720px, 960px or 2048px wide
  • Cover photos: 851px by 315px
• To avoid compression when you upload your cover photo, make sure the file size is less than 100KB
• Save your image as a JPEG with an sRGB colour profile
• 
  If it is for your own website then you set the display size in the layout, and this will tell you what size to make them.

 

[sirch]

so could I offset the effect this has on my images by saving them as 'heavier' files, i.e. the same dimensions - say, 1000 px wide

I would think not in fact I would try the opposite. The website/hosting company might have say a 120k limit (seems a bit small but who knows) so I would supply images at or under the limit so that no further processing is applied on upload. That way the published images should be the one you supplied

 

[Phil V]

As Chris alluded earlier, the answer here needs to come from your website admin. Either the site itself or him are doing 'something' and to find a solution you need to understand the problem.

It might be user error on the part of the admin, it's not uncommon for amateur website builders to have no idea how to host pictures, and he may even be breaching the sites 'recommendations'.

He might appreciate your interest because he maybe doesn't understand why the images don't look as good as the ones he is receiving.