Have you ever encounter these problem, when you use Stable Diffusion and suddenly many girls appear in one frame, or the limbs are deformed, or the body is stretched out?
These are common errors when you use Stable Diffusion. The reasons for fixing them are very simple and many people often ignore them because they think they are not important.
The reason behind is the resolution and image ratio you have chosen are all wrong.
I will give a brief explanation about this, because as we know Stable Diffusion currently has two most popular versions: SD 1.5 and SDXL.
With version SD1.5, they are trained by million small resolution images, with a pixel size of only about 512x512. Therefore, when you choose an image size > 1.5 times larger than the resolution of 512x512, the AI will encounter many difficulties in the sampling and denoising process, then errors will certainly occur.
Similar to the SDXL model, although in terms of prompt understanding they are clearly superior to SD1.5, and the SDXL trained data is twice that of SD1.5 (1024x1024), but still, they still has the error of the human body being stretched out.
Although you can use negative prompts to prevented these errors, they will certainly still occur frequently, which really annoying.
So to avoid these errors from happening, I recommend adjusting the resolution to only 1.1~1.5 times than the original data training image size
And here are the tweaks that I often use, please pay attention to the ratio too (d ^o^ b)
1. 768x768 (ratio: 1:1) with SD 1.5 and 1024x1024 (ratio: 1:1) with SDXL: Portrait, logo, vector, close-up sports display)
2. 640x960 (ratio: 2:3) with SD 1.5 and 768x1024 (ratio: 3:4) with SDXL: In cases you want to create full body view photos, cowboy shots, street landscape photos
3. 960x640 (ratio 3:2) with SD 1.5 and 1024x768 (ratio: 4:3) with SDXL: In case you want to create of many people, photos of natural scenes with many details.
