HDRI instead of Backplate too blurry/ Artefacts in Reflection

[ben_hamburg]

Hi,

in our current project we are using a high resolution (9298x4649) HDRI for Lighting and Reflections.

I plugged the HDRI in a Vray domelight and also in the environment background.

I noticed two problems though:

1. The backgrounds are too blurry to use instead of backplates. It works for shots with a FOV higher than 60°, but we need lower FOV on some shots.
We would simply use the supplied JPG Backplates, but some shots have 180° turns and we´d need to stitch some of the backplates together, which is not only a hassle, but also not very flexible.

2. There are some artefacts in reflections, they look like big, blurry pixels. Once again, can be fixed be using Reflection Plates, but it´s just another step, that seems unnecessary.

Can somebody maybe shed some (image based...) light on these issues?

[chriserskine]

is it just a sky you are trying to reflect or a scene with more detail?

short answer is not enough res, esp if you are using higher zoomed in shots.

that res would have been shot with a fisheye lens on camera a few years old.

D800 now with fisheye would get about 16k, and at 24mm 30k x 15k.

saying that i use only slightly higher res than that for 95% of my work with no back plate. but i generally don't use higher than 24mm lens, and its only sky in the hdr.

[Dariusz Makowski (Dadal)]

is it just a sky you are trying to reflect or a scene with more detail?

short answer is not enough res, esp if you are using higher zoomed in shots.

that res would have been shot with a fisheye lens on camera a few years old.

D800 now with fisheye would get about 16k, and at 24mm 30k x 15k.

saying that i use only slightly higher res than that for 95% of my work with no back plate. but i generally don't use higher than 24mm lens, and its only sky in the hdr.

I shot with D800 and 8m Fisheye... I only get 10k res out of that :/ As to 30k at 24mm well its down to scene I shoot mine hdr in 5 images thanks to that I can capture quite a lot of detail quickly(say walking people etc etc they dont get too bad..)

I think there is no fix for ur problems. We all have it. We all deal with it. Its pretty normal. Unless U want to start shooting ur IBL and Backplates using IQ180....

[cheerioboy]

Hi,

in our current project we are using a high resolution (9298x4649) HDRI for Lighting and Reflections.

I plugged the HDRI in a Vray domelight and also in the environment background.

I noticed two problems though:

1. The backgrounds are too blurry to use instead of backplates. It works for shots with a FOV higher than 60°, but we need lower FOV on some shots.
We would simply use the supplied JPG Backplates, but some shots have 180° turns and we´d need to stitch some of the backplates together, which is not only a hassle, but also not very flexible.

2. There are some artefacts in reflections, they look like big, blurry pixels. Once again, can be fixed be using Reflection Plates, but it´s just another step, that seems unnecessary.

Can somebody maybe shed some (image based...) light on these issues?

this might solve problem #2, http://www.peterguthrie.net/blog/201...y-reflections/

[chriserskine]

yeah you might just have to replace with a reflection plate.

I've shot a few pano's with d800 at 50mm, getting 66k x 33k. but there no way I'm going to shoot hdr at that res. its already a 12gb psb at 8bit. (jpg stops working after 30k)

[ben_hamburg]

So, project is done and I just wanted to close this thread by saying...

1. Yep. Only workaround is to use stitched backplates. Managed to stitch together a 360° Backplate from the provided Jpgs and just mapped that onto a cylinder...
2. The Tip from Peter Guthrie about the artefacts worked like a charm. Might be a good idea to include that option in the domelight parameters for future releases.