TIP: Resolution, Pixels And DPI (locked)
davoid
222 posts
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Confused about resolution? Don’t know pixels from pixies? Think DPI stands for Direct Petrol Injection? You’ve come to the right place. I’ve written a beginner’s guide called, funnily enough: Resolution, Pixels And DPI Enjoy! |
countrypix
10 posts
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Maybe someone has already asked this question before. If so , my apologies! |
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davoid
222 posts
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countrypix. Sorry I missed your question, there’s no notification on Forum comments. See my other guide: From Camera To Upload – Workflow Go to the Aspect Ratio section for instructions for use with Photoshop. If you’re using another image editor the instructions should still be helpful. I’m not sure, but I don’t think Red Bubble’s upload manager will let you upload 4:3 ratio images anyway. Feel free to email me. |
Sara Lamond
2415 posts
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RB lets you upload any aspect ratio. The only time it’s a problem is for cards, which are cropped to fit a specific aspect ratio which escapes me at the moment. Prints are printed in the ratio you upload – even panoramas. Ratio is not an issues aside from the cards. |
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davoid
222 posts
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Thanks Sara. |
louishiemstra
3 posts
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Hi Thanks for this incredibly helpfull forum! I shoot in RAW on my Canon 20D – the resulting files are CR2 – I open these in Photoshop CS2, and then save them as JPG’s The resulting jpg’s have a high amount of archiving, despite the fact that minimal editing of the CR2 file was done. The RAW files are around 7MB in size, but the JPG’s are quite small (less than 1 MB), although pixel dimentions are still 3504×2336. When I use the ‘print size’ button in Photoshop, it looks really small compared to when I shoot in max quality jpg. Confused!! What am I doing wrong? Please help! thanks everyone |
David Iori
202 posts
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what quality are you saving the JPG’s in |
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louishiemstra
3 posts
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Hi David, Available settings when opening the CR2 files are: Depth: 16 bits/channel |
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davoid
222 posts
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@ Louis My first thought is that Photoshop’s Image Quality goes to 12 and you set it to 10. 1. Image Quality = 12, Baseline (Standard): 2. Image Quality = 12, Baseline (Optimized): 3. Image Quality = 10, Baseline (Standard): 4. Image Quality = 12, Baseline (Optimized): So you can see; setting the image quality at 10 and maximum reduced the file size by half. I recommend: This will result in the least amount of compression possible. Regarding the Print Size preview in Photoshop being much smaller than usual: my first thought was that the resolution of the file must be very high, eg. 1200dpi, as Photoshop’s Print Size preview uses 300 DPI as it’s preview size. But I noticed you saved at 350DPI which wouldn’t make that much difference. Change it to 300DPI to match Photoshop preview for a slightly larger image. |
Will Hore-Lacy
73 posts
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The “DPI” that an image is saved should have nothing to do with the file size, the only thing that affect the file size (of a given image) is the number of pixles in the image and the compression applied (type and amount). I save most of my images at 11 coz it seems to be about the same as what comes out of my camera, saving them at 12 increases the file size. That said, if it is only of my best the I’ll save it at 12. Just keep in mind that something that affects the image size of different photos is the number of colours and if they are next to each other. JPEG compression actually groups like colours together so if you have an image that is mostly the one colour then it will compress much more. |
gordontant
3463 posts
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if you want the ratio for greetings cards, 1.14:1.62, which equates to 114mm x 162mm (c5) size, in redbubble dpi means noting because if you set your image size with the top pixel size, in image sizing then dpi doesn’t come in to it. dpi (dots per inch) is a conversion tool for you to work out in a measured distance how big your image will be ie 3000 px at 300 dpi is 10 inch |