# Gallery Pro image sizes

**URL:** <https://forums.realmacsoftware.com/t/gallery-pro-image-sizes/55258>\
**Category:** Elements\
**Created:** [March 22, 2026, 10:24pm UTC](https://forums.realmacsoftware.com/t/gallery-pro-image-sizes/55258 "2026-03-22T22:24:20Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![tinalyd](https://dub1.discourse-cdn.com/flex005/user_avatar/forums.realmacsoftware.com/tinalyd/32/1111_2.png) [@tinalyd](https://forums.realmacsoftware.com/u/tinalyd)\
**Post date:** [March 22, 2026, 10:24pm UTC](https://forums.realmacsoftware.com/t/gallery-pro-image-sizes/55258/1 "2026-03-22T22:24:20Z")

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Hi

I have a few questions about image sizes and large collections.

How do I choose file sizes in thumbnails without degrading quality. The lightbox image sizes are smaller than the thumbnails. How come.

I have a large collection in a submenu and want to divide it into smaller sections. Like 20 x 2 under folders. How do I do that.

@Dan or @Ben I would really like to see a more detailed video about Gallery Pro.

Best Tinalyd

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**Author:** ![dropgates](https://dub1.discourse-cdn.com/flex005/user_avatar/forums.realmacsoftware.com/dropgates/32/34206_2.png) [@dropgates](https://forums.realmacsoftware.com/u/dropgates)\
**Post date:** [March 23, 2026, 12:09am UTC](https://forums.realmacsoftware.com/t/gallery-pro-image-sizes/55258/2 "2026-03-23T00:09:59Z")

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There’s no magic number for use this size, but a simple rule of thumb is:

Thumbnail width = [container width](https://www.browserstack.com/guide/common-screen-resolutions) divided by the number of columns

Export size = thumbnail x 2 (for retina)

Use compressed jpgs, but webp would be better.

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**Author:** ![ben](https://dub1.discourse-cdn.com/flex005/user_avatar/forums.realmacsoftware.com/ben/32/28488_2.png) [@ben](https://forums.realmacsoftware.com/u/ben)\
**Post date:** [March 23, 2026, 7:53am UTC](https://forums.realmacsoftware.com/t/gallery-pro-image-sizes/55258/3 "2026-03-23T07:53:25Z")

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> [@tinalyd](#):
>
> How do I choose file sizes in thumbnails without degrading quality.

You specify the desired thumbnail size via the Thumbnails → Width setting. This setting is responsive, so you can override it for each device.

 ![CleanShot 2026-03-23 at 08.50.16@2x](https://europe1.discourse-cdn.com/flex005/uploads/realmacsoftware1/original/3X/1/4/147d22f921253ae380e8998b0adb0d299b174944.png)

> [@tinalyd](#):
>
> The lightbox image sizes are smaller than the thumbnails. How come.

Hard to say without seeing your project settings, however, you can control the lightbox image sizes via the Lightbox Media → Image Size setting.

 ![CleanShot 2026-03-23 at 08.52.22@2x](https://europe1.discourse-cdn.com/flex005/uploads/realmacsoftware1/original/3X/1/4/14394c6c0afb0b9d9a229c20b4aaa3686307e39e.png)

Hope that makes sense, but do let us know if you need any more help 🙂

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<div class="post-metadata">

**Author:** ![tinalyd](https://dub1.discourse-cdn.com/flex005/user_avatar/forums.realmacsoftware.com/tinalyd/32/1111_2.png) [@tinalyd](https://forums.realmacsoftware.com/u/tinalyd)\
**Post date:** [March 23, 2026, 3:31pm UTC](https://forums.realmacsoftware.com/t/gallery-pro-image-sizes/55258/4 "2026-03-23T15:31:22Z")

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Hi Eric.

Your math explanations is very useful. I will try to export the images once again. Maybe it’ll help with my problems.

Your link about screen resolution is also helpful,

My problems is that I have a lot of different dimension images. Some tall and narrow and some wide and high in the same submenu. I Guess I have do the work before importning them into Elements.

Thanks again for helping me out.

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<div class="post-metadata">

**Author:** ![tinalyd](https://dub1.discourse-cdn.com/flex005/user_avatar/forums.realmacsoftware.com/tinalyd/32/1111_2.png) [@tinalyd](https://forums.realmacsoftware.com/u/tinalyd)\
**Post date:** [March 23, 2026, 3:47pm UTC](https://forums.realmacsoftware.com/t/gallery-pro-image-sizes/55258/5 "2026-03-23T15:47:47Z")

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Can you help me with this.

I have a large collection in a submenu and want to divide it into smaller sections. Like 20 x 2 under folders. How do I do that.

I have one a menu item called galleries and 4 submenus and one of the submenu called Mezzotint and it contains 52 images. How do is make smaller collections with less image in the same submenu. Is it better to make two submenus called mezzotint 1 and 2. In the main submenu. If you understand what I mean.