Problem with Cycles Rendering

I’m sorry if this is the wrong place to ask about Cycles, but here it goes anyway. I’ve been following Jonathan Williamson’s Introduction to Cycles tutorial on So I followed the tutorial at the end and created a glass bottle with liquid. SO, after completed it and everything I proceed to render it in cycles with 500 Samples. So I noticed a few “specks” of white noise, so I thought I would go ahead and render it again with more passes. Not only was there still white noise (and you will see in the pictures), but there was more (and that was a 3800 sample render). So I just completed a 63 minute, 5000 sample render, and I get the same result.

In case you didn’t realize by now, I’m learning Blender and Cycles, so I’m sure it’s something I did, and I re-modeled the scene twice. Pictures are below and any help would be fantastic. Thanks!

3800 Sample Render:

5000 Sample Render:

Could there be anything else in your scene that could be causing the specs? Like something else that’s emitting on the glass?

And your first link is messed up you have an extra “p” after png.

It won’t let me change the link, so here it is:

(That is the 3800 Sample Render)

Here is something I discovered: I don’t get any white noise (like the above noise) when rendering in the viewport at 800 samples. When I’m rendering from the camera, the specks show up around the 300th sample.

I tried the solution in the thread, but at 400 Samples I’m getting the same noise… :frowning:

try this solution, it worked for me …

Blender 2.3 has a new clamp setting in the integrator that deals with fireflies.

Old known bug in glass shader or/and other related parts, hard to fix, use post process like GIMP despeckle filter as workaround.

Did you use any area lights? or just Mesh Emitters? I’ve not had much issue with Fireflies and real glass, just noise. If you’re not bothered with the IOR, you could always make a mix shader of Transparent and Glossy to simulate glass - although that tends to works better for windows etc.

I think @Jay-artist is right. The problem could be to use area lamps. Change them for meshlights. I think thant noise will disappear and you will see some kind of specular reflexion.

Yes, I found out it was because I had the default area lamp in my scene, and when I deleted it and re-rendered, it came out fine. The GIMP De-speckle filter also works too. Thanks for your help everybody, happy Blending! :stuck_out_tongue:

I have a Dell XPS L702 laptop with a Nvidia GeForce GT 550M graphics card, and I find that my renders only go as far as a small square in the middle of the image and then the render doesn’t continue, as if Blender freezes. Is this normal at all for the cycles? I started using Blender last week, having moved from Maya and After Effects, as I can’t afford the money they ask for their products, now that my college course has finished and I need a software to do work on. I have found Blender super useful in it’s sense that it can do everything from modelling, to pushing out a final production. I use objects with the emission shader assigned to them for lighting and rendering with cycles, instead of using lights for the render as I believe that’s what the Blender Guru tutorial teaches. I also worked through the tutorial that is hosted by and presented by Gary Maestri, a really awesome tutorial, taught me everything I needed to know for getting started. Just curious if this behaviour for the cycles has occurs with the rest of you guys as well?

it is normal if you use final render and tiled, and you have very hard scene, or too high “samples”, cycles just rendering first tile that take a long. Decrease “samples” and try again.

I dad that and it worked, Blender would place a few tiles at a time, render them somewhat, then place more tiles and render them a bit, and it would continue this way until all the tiles have been placed and the image is finished. I rendered a test of this in 30min an dthe results were satisfying. Thank you for your help. :smiley: