What is the ideal resolution to upload to AstroBin so it looks best? Is there some kind of formula or preferred pixel dimensions?
Quinn Groessl:
I prefer ones that are able to have the nice zoom that Salvatore mentions. I never knew the size limit, but from now on that's the largest I'll submit.
Salvatore Iovene:
I don't think there's a specific resolution that looks best. AstroBin will of course resize your image to various smaller size for optimal display in various places (as of course it doesn't make sense for the browser to download the full resolution to display it as a small thumbnail, for instance).
When it does so, it tries to keep the quality as high as possible and reasonable.
Ultimately, there are a couple of constraints:
1. Images larger than 16536 pixels on one size will always be scaled so that the long size is 16536 pixels
2. Images with a total number of pixels larger than 32768 x 32768 will not be accepted at all
3. Images larger than a total of 8192 x 8192 pixels will not be able to be zoomed in with the nice zoom, but you'll get your native browser display in a new tab
If you're looking for the "optimal resolution" that displays the best, I'm afraid that it doesn't exist, because it depends on factors that AstroBin or you cannot control, such as the properties of the device that the viewer is using.
John Hudson:
Also full size tends to look a bit soft when re-scaled
Salvatore Iovene:Quinn Groessl:
I prefer ones that are able to have the nice zoom that Salvatore mentions. I never knew the size limit, but from now on that's the largest I'll submit.
I would recommend against that. Technical limitations are temporary, while images are forever, and at some point I might find a memory management trick to make the zoom work on larger images, and/or bump it up in the future as device get more and more powerful.
When that happens, the nice zoom will work on larger images too, but you are unlikely to come back and update your image with a higher resolution.
Hartmuth Kintzel:
Unless it is a large panorama image, I would always try to keep the image size such that the Astrobin zoom works.
It is much more comfortable for the viewer.
Salvatore Iovene:John Hudson:
Also full size tends to look a bit soft when re-scaled
I've never heard this one, but the full size doesn't get scaled unless one side is longer than 16536 pixels.
John Hudson:
The view that one gets from the main image page, whatever it happens to scale to, where you can see the other details and plate solved etc. That image tends to be softer than if you were looking at it in Photoshop for example. But I think here are image sizes that may look better there, so I will experiment with it.
Salvatore Iovene:
I guess the best way for me would be to create a 8192x8192 maximum resolution image to use in the zoom viewer, and offer a button to view it at full size in a new tab for images that exceed that size natively!