Hi there,
I have created my own hdri using an Insta360. I’ve exported out the image in Insta360 Studio and then completed it in photoshop by using ‘Merge to Hdri’ and then saving as a ‘Radiance Hdr’. When I render the Hdri in cycles, I don’t get any shadow from the sun in the image. The object I’m rendering is a house which would naturally cast shadows on itself. I’m not using the Shadow Catcher. The hdri was taken on a sunny day. I wonder if I’m missing something small along the way?
I expect that there is some cutoff, that very bright sun is not recorded or in Cycles there is light clamping.
If it is light clamping, it may be good idea to adjust to level where sun is clamped but sky is left, and add sun light source there. Then you avoid fireflies.
Hi SterliingRoth,
Yes, you are correct. I’m getting L1.788 on the sun. Does this mean that when I export the HDRI from Photoshop, I need to lower the levels?
I’ve exported out another HDRI and lowered the exposure. The L level is now. 0.8, but I’m still not getting shadows. I can’t help feeling that I’m missing something here.
No, I think that he means that you don’t really have an image with a large range. 1.7 is higher than a 1 or less you find in an LDR image, but still it’s far from the values you must find in an HDRI file. I have one from HDRI haven and it’s not too bright, but some light values of a fluorescent lamp go over 4.7, so you can imagine how low your sun is.
Thanks for the info Rodrigo. I’m combining 10 hdr images from the Insta360 which vary in value from pretty dark to very bright. I think I’ll have to do a bit more research on the way I’m processing the images.
I am not an expert in that matter, but what I understand about photos tells me that there’s a big difference if you start in a place where you have large areas of shadows and another where you have everything reasonably well lit. Where was your measure taken? If you make a measure in an area with hard light you tend to have smaller values for the sun than if you take the measure from a middle lighted point. How big was the difference between your very dark and very light images?
Hi Rodrigo.
The difference was pretty big. The insta360 one R camera takes a 10 shot burst in hdr format, going from very dark to very bright. I’m pretty sure that I’m just processing the images wrontly.
I’m using Insta 360 studio to process the original images. Then I export them out and process them in Photoshop. I’ve also tried processing them in Affinity photo. I export them out as 32bit Radiance images.
Did you ever give Hugin a try? It’s open-source, so I believe it could be interesting.
Here is a tutorial on how to make a high dynamic range image using Hugin and the same process could be used for environments. https://www.youtube.com/watch?v=ckP8FFfKsDI
