Image size/resolution for Kindle page?

[Book Illustrator]

I understand that Amazon charges 15 cents per megabyte of book you upload. I want to get by with the smallest resolution that I can per image. 72 pixel per inch is likely the standard but is there a maximum inches-by-inches standard that a Kindle page has? I want to be covered for any Kindle device and not have pixelated images. I'm assuming images in Kindle books are mostly or all jpg and often saved as a 6 out of 12 size jpg in Photoshop.

[JSWolf]

You do need to make your images high resolution because of the 300DPI screens being used.

[Book Illustrator]

Thanks. I just have to figure out the biggest inches by inches dimension of a Kindle device.

[AnemicOak]

Originally Posted by Book Illustrator

Thanks. I just have to figure out the biggest inches by inches dimension of a Kindle device.

Keep in mind that Kindle book does not only mean Kindle device. It also means Fire tablets, Android Tabs & Phones, iPads/Phones, PC/Mac screen, etc. There are a lot of Kindle book purchasers who don't use an actual Kindle.

IIRC they used to have a file size limit on interior images, something like 250kb each, but that might have been 4 or 5 years ago and could have changed. Hopefully someone will come along who knows for sure.

[jhowell]

I recommend checking out section 9.4 (Image Guidelines) in the Amazon Kindle Publishing Guidelines.

Some highlights:

Use a resolution of at least 300 ppi for all images.
...
The maximum size of a mobi is 650 MB. KindleGen performs automatic image conversions to optimize the content for Kindle. You can obtain the best results by optimizing your images to the highest quality possible within the file size limit before inputting your files into KindleGen.
...
Photographs should use the JPEG format and be saved at high quality. (In Adobe Photoshop, choose Save As, select JPEG, and click Save. In the following JPEG Options dialog box, choose a Quality level of 10 or higher.) Photographs should use the highest resolution available within the file size limit.

Photographs of less than 300 x 400 pixels create a poor customer experience on high-resolution devices.

Amazon recommends that images display clearly at 2X magnification across devices. This means that if an image is intended to display at full width on device, its width should be captured at 3200 px (this is twice the width of our highest resolution device, the Kindle Fire HDX 8.9”). Smaller images can be resized
accordingly.

Of course these are only guidelines.

[Book Illustrator]

Thanks, AnemicOak anf JHowell.

The more photos/images, the less potential profit, unless you raise the book's price. That has a de-incentivizing effect on including images and, as a result, negatively affects photographers and artists.

[dwig]

Originally Posted by Book Illustrator

...Kindle books are mostly or all jpg and often saved as a 6 out of 12 size jpg in Photoshop.

NEVER EVER "Save..." as JPEG (or PNG or GIF) from Photoshop when the image is going to be used either in an ebook or on the web. You should always use Ps's "Save for Web & Devices" option instead.

Ps's "Save..." and "Save as..." functions will include a range of Photoshop specific ancillary data (e.g. guides, certain Save dialog settings, ...) and thus create larger files, for the same quality, than its "Save for Web & Devices".

[jhowell]

Originally Posted by Book Illustrator

The more photos/images, the less potential profit, unless you raise the book's price. That has a de-incentivizing effect on including images and, as a result, negatively affects photographers and artists.

That depends on the royalty option you choose. With 70% royalty you pay delivery cost and so have incentive to use little or no graphic content. With 35% royalty Amazon takes care of delivery and so you have incentive to sell the best quality book that you can with lots of high-res illustrations.

[Book Illustrator]

Dwig, Thanks for your reply. I'm using the latest ver. of PS. I see File>Export>Save for Web(Legacy) which implies that there is a new way of saving for the web so it seems that there is something in Photoshop CC 2015 called Adobe Generator that I'm now researching: http://blogs.adobe.com/crawlspace/2015/06/save-for-web-in-photoshop-cc-2015.html

[jhowell]

Originally Posted by dwig

NEVER EVER "Save..." as JPEG (or PNG or GIF) from Photoshop when the image is going to be used either in an ebook or on the web. You should always use Ps's "Save for Web & Devices" option instead.

Generally a good idea, but kindlegen processes images and strips out all of the cruft anyway.

[Book Illustrator]

JHowell, have you had a Kindle book with images published? I'm curious if you're satisfied with the way the images look after the kindlegen process vs the original image quality.

[JSWolf]

Originally Posted by dwig

NEVER EVER "Save..." as JPEG (or PNG or GIF) from Photoshop when the image is going to be used either in an ebook or on the web. You should always use Ps's "Save for Web & Devices" option instead.

Ps's "Save..." and "Save as..." functions will include a range of Photoshop specific ancillary data (e.g. guides, certain Save dialog settings, ...) and thus create larger files, for the same quality, than its "Save for Web & Devices".

You can save as JPEG from PS. Then use Calibre to losslessly compress the images. That will get rid of the crud in the graphic files.

[dwig]

Originally Posted by JSWolf

You can save as JPEG from PS. Then use Calibre to losslessly compress the images. That will get rid of the crud in the graphic files.

If the Ps saved image is a JPEG or JPEG compressed PNG then reprocessing it will degrade the image quality. If Polish simply strips the image metadata then no damage to the image data will occur.

[jhowell]

Originally Posted by Book Illustrator

JHowell, have you had a Kindle book with images published? I'm curious if you're satisfied with the way the images look after the kindlegen process vs the original image quality.

No I haven't published a Kindle book. I just use their tools for my own purposes.

[Book Illustrator]

Thanks, JHowell.