So currently I'm watching Andrew Price's tutorial on "How to Make a Cave in Blender - Tutorial". I've made some progress, and decided to make a nice render - this is a screenshot of the rendering progress:

rendering progress

You can't see that well, but the rendering is at path tracing sample 2000 of 1000000 (one million). By then it's been running for two hours. But when I compare this picture with Andrew's final render of his cave, I notice the differences:

enter image description here

You can notice mine scene has a lot of noise compared to Andrew's, which is silky smooth (Even though my picture is bigger). How many samples should I have? Am I missing some rendering settings? Should I let the samples do their thing all the way to one million? (There's 1057 hours left... that is 45 days)

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    $\begingroup$ You definitely shouldn't have to use a million samples! Check out Andrew's article on fireflies here. You can also check out this question. $\endgroup$
    – PGmath
    Commented Oct 1, 2015 at 16:15
  • $\begingroup$ @PGmath thanks for that, I think I got a clearer idea now $\endgroup$ Commented Oct 2, 2015 at 17:22
  • $\begingroup$ One thing to note, you are having noise problems. Not fireflies. Fireflies are bright white pixels that have little in common with overall noise. In fact, the clearer your render is, the more fireflies will appear.. $\endgroup$ Commented Oct 2, 2015 at 19:56
  • $\begingroup$ Right! Still a noob i guess, so I gotta get all the terms in place... $\endgroup$ Commented Oct 2, 2015 at 20:05
  • $\begingroup$ Also, it seemed to get much clearer at sample 4000 or something (don't remember), you can check the result here $\endgroup$ Commented Oct 2, 2015 at 20:07

2 Answers 2


I've followed that same tutorial a while ago when I was just starting, and I might be able to help a tiny bit. This is what my result looked like: enter image description here

That is 1440p. I think I used 2000-3500 samples for the final render. And I only used that much because I left my computer on overnight and while I was at school. It took a long time, somewhere in the realm of 14 hours.

That being said, I realized fairly early on that there is a limit to how good a picture can look given the scene and settings, no matter how many samples you use. I think my picture would have just as much noise if I used 10000 samples; after a certain point it just doesn't matter.

That being said there are several things you can do to increase quality and time of your render, and I highly recommend that you look up how to do all of these. Here are just a few of them:

  1. Use GPU rendering rather than CPU.
  2. Change the tile size to accommodate the type of rendering (CPU or GPU).
  3. Turn down the amount of light bounces.
  4. Use portals.
  5. Bake the Lighting.
  6. Decrease the resolution.

The most important thing you can do as a beginner at your stage is this: don't judge your render until you are closer to being finished, there is a lot you can edit along the way. Also there's absolutely no point to using an absurd amount of samples to preview an image, (again, until you're closer to being finished) you're going to add more to it anyway, and the preview isn't supposed to look like the final result.

If you're an absolute beginner, I would highly suggest starting somewhere easier. tutor4u (youtube) has some amazing step-by-step tutorials for a lot of things. As a novice myself, my main advice is to not overload yourself with scenes as advanced as the one you're trying to do, (and don't use 1 million samples, even 2500 is too much).

  • $\begingroup$ Nice first answer! I hope you continue to use the blender SE platform, it is a great resource for beginners and professionals alike. $\endgroup$
    – 10 Replies
    Commented Dec 3, 2016 at 1:18

Afaik, There is not a single way, many factors weigh in, and you have to find which fits better for you... since you follow Andrew Price, have you already tried what he suggests here http://www.blenderguru.com/articles/7-ways-get-rid-fireflies ?

And, add to those sugestions from Andrew the relatively new "portal" feature, because that could change all... check: http://wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.75/Cycles http://www.blenderguru.com/tutorials/using-portals-accelerate-render-times/

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    $\begingroup$ Additional helpful reading: wiki.blender.org/index.php/Dev:2.6/Source/Render/Cycles/… blender.org/manual/render/cycles/reducing_noise.html $\endgroup$ Commented Oct 2, 2015 at 20:50
  • $\begingroup$ Just to add a thought - you can try rendering at different exposures, and even darken the cave in post production. Dim lighting and small light sources tend to produce fireflies, so one solution could be to render with more light, then darken by other methods. Also, notice how much more light is entering the cave in Andrew's scene. The cave entrance is larger and closer to the camera. $\endgroup$
    – Mentalist
    Commented Oct 7, 2015 at 7:43

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