Originally Posted by Hitch
Well, I just tested a mobi that was made with a 600x800 original cover size (n.b.: we make our mobi's from ePUBs, via Previewer and/or Kindlegen, depending upon which Crew here you query. The NoteTab Pro crowd explode the ePUB and feed the OPF to KG; the PERL gang feed the ePUB to Previewer--six of one, half-dozen, etc.) I uploaded the mobi (1.839KB) with the embedded 600x800, and then I uploaded our "standard" 960x1280px jpeg as the product image. The final file was fine, no dual-covers (and I've had no reports of same in somewhere between 3-500 books we've done since the changeover--I can't remember what date they took the "option" out), and the final file is 1.7MB...so it seems to work fine.
I'm pretty sure if we were accidentally creating dual covers, I'd have heard by now from one of our clients; I mean, they pour over the samples and Look Insides relentlessly, so certainly out of that many hundreds done in this timeframe, I'd know.
Does that help? Covers look great, or as great as can be realistically expected with that compression ratio. It's hard to walk the fence between the "product image" needs and the embedded cover needs, and so you get some lossiness, no two ways about it--but remember: the bottom line, no matter how painful it is, is that most purchasers don't really look at the embedded cover anyway--it's a pre-sale item. If you have to choose, choose what will look good on the Amazon/B&N website, not INSIDE the book, because the "grabber" is the product image version. Now--that's just my opinion, and worth what you just paid for it. ;-)
Thanks Hitch, very helpful. Great to know there are no dual cover issues, and since your file size actually decreased I can only assume Amazon removed your 600x800 cover from the file, and fed in the new one (compressed), without adding to the files size. Bodes well for delivery cost
In my test last night on the Amazon upload site, I had a 600x800 image embedded, then uploaded a larger cover image file (1612x2474) with different aspect ratio (closer to the recommended 1.6 ratio). Upon conversion on uploading my book file, the embedded cover was replaced with a compressed version of the larger, different aspect ratio file, which didn't fill the screen properly in the Previewer on the Amazon site. So while I'm fine with their new single upload process in terms of having the embedded cover replaced, I don't understand why they recommend the 1.6 ratio of that doesn't fill the screen when they convert. I will go back and upload a larger file having the same 1.33 ratio as the 600x800, which is what I understand you did.