Photo Size for the latest tablet resolution

Hello Guys,
before i am new in the forum. My name is Claudio Giovenzana, from italy. I am travelling taking picture and writing… unfortunately mainly in italian.

Anyway… i am converting to epub on of my book and i wonder which is a FUTURE PROOF photo resolution considering the increasing quality of the tablet in the market…
Here i have read that a good rule of thumb is 800x600 72 dpi… but i wonder if it is enough for devices with retina display
i am a photographer so i have plenty of very good photos to put in the ebook i don’t want to leave them low res and size to save space… a good balance between quality and size would be great

Any idea?


Future proof would be to treat digital work with the same quality that we currently do for print work. Although most printers do not actually print at 300 DPI, that’s the industry standard because it is much easier to scale something down than up. So tablet bearing book sellers like Amazon and Apple are currently suggesting 300 DPI. This works well with the current crop of high resolution displays (which are around 200 to 300 pixels per inch, and likely won’t need to go much beyond that as we’re getting close to what the human eye needs to see things clearly). In my opinion that’s something to shoot for one if quality really matters (which it sounds like it does), because that really going to bloat the book size by a lot, especially if there are many images.

Thanks Ioa,
i have to do the math to discover a full tablet page photo would weight at 300 dpi… quite scare about it,
Astrid told me there are some size restriction for the ebooks in some websites.
so i better take care of it.

And last but not least,
I open the epub with calibre or digital edition and when i resize the page the image lose the aspect ratio to fit in the page… is there an option inside scrivener to preserve ratio? (when i double click the image i leave checked the option “lock aspect ratio” … but it doesn’t work)

thanks a lot!

Yup, that’s the main problem right now with these new recommendations—they don’t sit well with the existing infrastructure. Most people aren’t ready to be piping 30mb e-books over cellular or otherwise, and most vendors either have size restrictions, are start to charge you quite a lot for delivery fees to customers. That’s why I say I think you should only consider it if quality is important. Even just a cover graphic by itself would set the book far above what most others are in total. Finding the quality vs. vendor specific cost line and getting as close to it will be the name of the game for now.

Aspect ratios: I think this is a peculiarity of these two readers, because I’m not sure what else could be done from the HTML side. Scrivener already declares a width and height, so if the display is squishing it rather than downscaling on the short side, well that’s how it was programmed to display images for some reason. It seems an odd choice to me.

Do you mean “Scale to fit”? That’s the only checkbox in that tool; it means to scale the graphic so that it fits into the editor box. There isn’t actually a way to squish the image in the editor—it always maintains aspect ratio, but whatever the case that is only for the editor itself. It doesn’t alter the image in any way.

Yes i mean scale to fit (sorry about my english)
in digital edition the image keep the same aspect ratio but it doesn’t scale…
in calibre it squeeze and distort a lot…

any idea?
wher i double click on an image the “RESIZE IMAGE” box appear… (last version of scrivener for mac)
and there is width scroll bar… height scroll bar… and lock aspect ratio check box

i cannot find the SCALE TO FIT option you did mention me …

Sorry, I misunderstood you on the “Lock aspect ratio” bit, you are right about that. I was thinking about when you have a graphic dropped into the Binder and double-click on it in the editor—not when it is dropped into the text editor as a figure. That box does impact the output, but the lock aspect ratio just locks the two sliders together.

Okay, for Adobe Digital Editions, it should be coming out the same size as it shows up in the Scrivener text editor. That is the result that I get anyway. I tried several different DPI settings on the same exact picture (no interpolation, just switching the display size) and they match the original size in ADE. Try using the slider in Scrivener to increase the size (that just adjusts the display size, it doesn’t damage the pixels, so feel free to play with it).

As for Calibre, again I don’t know why it has been designed to stretch images like that. It isn’t normal and no other e-reader I know of acts that way. I suggest just leaving its viewer window size alone, as that is shaped to mimic a common e-reader display anyway.