high res texture render result gets blurry as camera pulled away

[daniel.xiaohong]

So I have this problem, I have 7 or 8 "screens" in my scene, to achieve certain effect, they have to share the same uv map that contains all the screens content, the camera starts in a close up position then pull away to a wide shot, in order to keep the screen sharp when it's in a close up position, I created the image sequence in 9216*9216 resolution.

It's fine when the camera is up close, sharp, bright, all works out, but as the camera pulled away, the render result gets blurry, the image gets dark, the model's screen gets dark,(*I was planing on increase the emission value as the camera pulls away to fix this "gets dark" issue. you might know a better way or why this problem occur, be great if anyone could help). the result is showed blow. to compare with what it should be look like, i scale down the same source image on the right hand side.

As you can surely see, it gets blurry.

I don't have depth of field enable in my camera just to be clear, I use arnold 5.0.2 in maya. I use after effect to create the image sequence, and it's all created properly, no one single image gets scale up and lose resolution.

Is arnold down sizing my texture?

[daniel.xiaohong]

by the way, i render these images in 1920*1080, sampling numbers are: 7,2,2,1,1,2.

[daniel.xiaohong]

@Lee Griggs?

[brian_Foley]

It looks like it could be a mip map bias issue. Is your mip map bias changing as the camera pulls away?

[daniel.xiaohong]

i wonder if i export the image sequence in tiff format, would it fix this problem

[lee_griggs]

Yes, the mipmap_bias control in the image node could be useful if you want to adjust just a few textures. Are you converting to .tx btw?

How are you lighting the scene?

[daniel.xiaohong]

here is the image node,

so do I just disable auto-generate TX textures? or make some changes to filter type? I did some test, where I disable auto-convert to TX in render setting-arnold renderer-textures globally, the result looks brighter for sure, sharp but a little over sharpening. I'm still testing.

here is how I light my scene, one the top is a bit of a right hand side back view with the perspective camera, on the bottom is side view.

[brian_Foley]

Try setting your mip map bias to a negative number.