Railfan Technology > Loss of sharpness uploading photos

Anyone here ever use the Polarr editing app or otherwise have a loss of sharpness uploading photos to TO? When I'm at home I use the Epson supplied software or GIMP to sharpen photos on a Dell laptop with Windows and they seem to look the same after uploading. But recently I bought a Chromebook to take on trips and I use the Polarr app to make a few adjustments if needed, including sharpening, but when I subsequently upload to TO there's a noticeable loss of sharpness in the photos and I can't seem to figure out why. I use a Canon T7i camera with a 24mp sensor so I know there's plenty of sharpness in the original (RAW or jpeg), and if I process on the Dell there's no loss of sharpness, only when I use Polarr. Should I try another editing app or is there something I'm missing? I can make the adjustments and leave the processed photo open in the app and compare it to the TO version after upoading and there's a clear difference, is it something with TO software and how much data is kept when uploading? Any help is appreciated...

JG

Over the years one story goes that TO has a file limiting feature used on images, the images larger than 1000 pixels in any direction are reduced, or compressed ( but compression is basically selectively throwing out pixels). Some folks have the opinion that if the poster reduces the image to 1000 pixels before attaching the image file, then the compression S/W is not used and the images seem to be sharper than if it had been compressed by the TO S/W. Most folks are hard pressed to see any difference caused by the TO compression, so perhaps there is something else going on.

Some Photographers on other sites, Landscapes for example, not RR, have a technique for reducing noise / sharpening, adjusting color and reducing file size in a series of steps, as opposed to one giant leap down to 1000 pixels. The info seems to always use a Photoshop product, don't know about other photo editting software. My opinion is that there are other styles of photography that use similar tools and techniques as what we use for RR photography. There are quite a few tutorial and training websites out there to check on.

Although I don't upload that many photos here, I did read some time ago about the 1000 pixels. I always reduce my images in my editing software to 999 pixels wide before uploading, and have never noticed any loss of quality onto TO. chris uk.

You save in your software you want to save at maximum quality, on some software there may be setting like save for email etc but use max, on ps there is a range from 1-12
This was saved at 1000 pixels or 652 kb.

Bob



Edited 2 time(s). Last edit at 12/14/21 07:41 by robj.

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This is saved at 1600 pixels or 1.32 mg.

Bob

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The file posted at 1000 pixels when downloaded back to my computer from TO's  is still 652 kb.

The file posted at 1600 pixels is now 334 downsized from 1.3 mg.

So the larger file size has been reduced to half the size ot the smaller file but even more importantly been downsized by system unknown.
Just in general every time a file is resaved it loses quality.

Bob


 



Edited 3 time(s). Last edit at 12/14/21 07:42 by robj.

The lossiness iof JPG is why I always save my work in TIFF....at least my originals are.....the may get jpg'd if uploaded somewhere but the deterioration that eventually results means it is no more good for anything but looking at on the tinterwebs. 

That should always be the standard. Tiff is archival and can be re-edited. Once a jpg is save data (pixels) have be thrown away and can never be recovered. Treat the tiff as an original neg or slide - make copies as jpg for email of posting on line.

RWJ

engineerinvirginia Wrote:
-------------------------------------------------------
> The lossiness iof JPG is why I always save my work
> in TIFF....at least my originals are.....the may
> get jpg'd if uploaded somewhere but the
> deterioration that eventually results means it is
> no more good for anything but looking at on the
> tinterwebs. 

LV95032 Wrote:
-------------------------------------------------------
> That should always be the standard. Tiff is
> archival and can be re-edited. Once a jpg is save
> data (pixels) have be thrown away and can never be
> recovered. Treat the tiff as an original neg or
> slide - make copies as jpg for email of posting on
> line.
>
> RWJ
>
> engineerinvirginia Wrote:
> --------------------------------------------------
> -----
> > The lossiness iof JPG is why I always save my
> work
> > in TIFF....at least my originals are.....the
> may
> > get jpg'd if uploaded somewhere but the
> > deterioration that eventually results means it
> is
> > no more good for anything but looking at on the
> > tinterwebs. 

Yes.  but also PSD ie photoshop files are also lossless and maintain PS information like layers etc.  I'd guess that PS interchangeable file format  is also lossless.
Files modified in Lightroom also use a side file, the original is not changed.

I'd also note if you are using a digital RAW file and doing most of your adjustments in RAW it would just create a lot of extra storage to save your final product as a TIFF.  You always have the original.
I think a lot of scans can be saved as jpg as long as you keep the original or first copy, the key is not keep opening making a change and closing again and again.
Of course then there is the subjective value of the file.

Bob
 

I've noticed that my most recent photos on TO are not as clear as they used to be.  For years I used Windows Photo Gallery to resize a copy for TO posting to standard sizes, and my photos always looked clear on TO.  Now I'm using Photoshop, and when I resize to the TO guideline standard my photos do not look sharp.  Maybe I'll try going smaller to see if the compression software does not modify them. 



Edited 1 time(s). Last edit at 01/01/22 19:19 by dwatry.