Edit or not to Edit

[Manfred M]

Are you confusing MB with MP, or am I not understanding the math? For example, I can save two identical images at a size of 1920x1080px - one at 8bit TIFF the other at 16bit. The MB figures would most certainly differ. I am obviously missing something and would like to understand.

Sorry Ted that was a typo and a bit of a mental mixing of MP / MB. Both numbers were meant to be MP and I qualified that i was referring to images resized for display purposes on the internet. My D800 produces ~ 36MP images whereas the 1366 x 768 display I am using right now ~ 1 MP means I am throwing away 35 MP of data if I scale an image for display (97% of the data is tossed).

My usual downscaling means the images that I display on CiC are at a maximum size of 2048 x 1367 = 2.8MP, so I throw away 33/36 = 92% of the data.

While I maintain the large image size throughout the edit process, most of the data goes when I resize for final display purposes. It doesn't matter which colour space I use or which bit depth I work in, the downsampling operation is where a lot of the data is thrown away.

[xpatUSA]

Sorry Ted that was a typo and a bit of a mental mixing of MP / MB. Both numbers were meant to be MP and I qualified that i was referring to images resized for display purposes on the internet. My D800 produces ~ 36MP images whereas the 1366 x 768 display I am using right now ~ 1 MP means I am throwing away 35 MP of data if I scale an image for display (97% of the data is tossed).

My usual downscaling means the images that I display on CiC are at a maximum size of 2048 x 1367 = 2.8MP, so I throw away 33/36 = 92% of the data.

Manfred, thanks for the clarification. Indeed, I often think about what size is "best" to post here and elsewhere. But with such a great variety of devices with which one can view images these days, from smartphones to 4K monitors, there is probably no "best" size.

Personally, I tend to shoot my Sigma SD1M in low-res (2x2 binned) mode which gives me a better SNR and more manageable ~12MP file sizes. That gives me 2336x1568px images and which, if saved half-size, gives me 1168x784px which fits my 1280x1024px monitor nicely and everybody's 16:9 monitors too probably.

Throwing data away is also a fact of JPEG life if one posts reasonable file sizes. Which makes me wonder if anyone posts PNG habitually here?

Here's one just for grins:



Only 1168x748px but the file size is uncomfortable, even at max (lossless) compression, it's a whopping 2.5MB; whopping, that is, to someone who prefers to post well under 1MB.

No blocky artifacts though

Incidentally, for this image, it only comes out 100% on my screen by right-clicking and selecting 'view image' (FireFox, Win7). Just left-clicking on the image causes it to be re-sampled (upward in this case) which I don't particularly like at all. I don't like it because, having spent time and effort processing at 100%, CiC re-samples it downward for the post and upward for the zoom size using algorithms which I know nothing about. In other words, what I posted is not what you'll see. Very irritating for this old pedant

Pardon me, therefore, if I am probably the only member here not celebrating the return of Lytebox or whatever it's called . . .

[Manfred M]

Ted - I've discussed this with a number of photographers (including some pros who use their websites as their primary marketing tools). Load time is really what we are fighting with here and there are so many different internet connection speed issues in the wild, that the consensus seems to be that 1600 pixels is a good tradeoff.

Some will ensure that their maximum dimension does not exceed 1600 pixels and the other stick to 1600 pixels max on the shortest dimension. This seems to allow for a decent amount of pixel peeping without taking forever to load.