360 spherical HDR tutorial

[jccloutier]

I am trying to create my own spherical maps to use in still image renderings because all the ones I use seem to be excessively blurry. I have the Dosch HDRI Skies, and Dosch Extreme Hi-res but when used as a spherical environment they look like 50 dpi x 50 dpi thumbnails.

 

Does anyone know of a tutorial that will take me from pulling the camera out of the bag to loading the hdr into the environment slot?

 

I've found thousands that cover some of the steps but i can't wrap my head around the issue well enough to get the entire process down.

 

I have a 10 mp camera ready to go but no skillz to pay the billz.

 

Thanks.

[batteryoperatedlettuce]

I want to try making some HDRs from my models using the 360 degree camera. any tutorials on this would be a big bonus too.

 

@ jccloutier There are some links to tutorials on making HDRI images on wikipedia if you search for HRDI. Sorry I can't be more specific, but it's difficult to get onto wikipedia at the moment because it's blocked from China.

[radii]

Making your own 360 HDRIs will not solve the low resolution look you get in 3ds max, if you use it in the environment background slot.

 

The only workable solution I have found, is to shoot a spherical HDRI at a certain location, and then take regular pictures of the location that you will later composit behind your rendered scene as a background in Photoshop. Use the HDRI only for illumination and reflection purposes, but not as a visible background.

 

There are some good tutorials online (can't remember the links), but the main thing to look out for when making your own HDRIs is WHITE POINT BALANCE !!!

[chris erskine]

I've been making 360 hdri's for a while now.

 

to make it work you need to spend a bit of cash on getting a tripod head that will allow you to move the camera back so you can rotate it around the nodal point of the lens.

 

my current setup for this is a manfrotto 303sph, nikon D200, 12-24mm lens.

 

with this setup i'm getting around 13k x 6.5k @12mm

 

also the added advantage of using the d200 is the 9-shot bracketing so i don't need to touch the camera to get up to a 9-stop hdr

 

there's no point trying to stitch 360 image without the proper tripod head. even if its only slightly out in the calibration it will couse a lot of problems.

 

but if you want to try it out there is a open source stitcher called hugin.

[jccloutier]

I've ...

 

Thanks Chris (and radii).

 

Could you please list the steps that you use for this process?

 

For example:

 

1. setup camera

2. take 9 exposures in 6 positions to complete the revolution (in .jpg format)

3. merge the 9 .jpg's into one .hdr file using X program

4. stitch the .hdr's using hugin

 

Thanks.

[chris erskine]

well first you need to calibrate the 360 rig. this involes moving the camera backwards and forwards until you stop getting parralex. this can be tricky and there is a bunch of different ways to do it. I've ended up making a grid the goes on a second tripod so you can see the difference in movement from the foreground and background objects in the scene.

 

as for photos taking the photos with a 12mm lens i shoot 34 per exposure or with the 10.5mm fisheye i shoot about 11 per f-stop.

 

you can shoot with less but i get better results taking a few extra.

 

then you need to go through a process of

lens correction (depending on lens and what zoom you may not need this)

stitching each exposure

merging stitched images into a single hdr

 

for stitching you could use hugin (opensource GUI for panotools), PTGui (based on panotools, cheap), or realviz stitcher (which is expensive).

either way you'll need to work out a method that stitches all the different exposures the same.

 

for the hdr merging you can use either HDRshop, photomatrix pro, or photoshop.

 

hdrshop isn't bad but it stops working at resolutions above 8192

photomatrix is better with tonemapping built in and works a little higher res around 10k or so.

photoshop is kind of crap but it will work at higher resolutions

 

well i hope that helps

 

chris

[jccloutier]

 

as for photos taking the photos with a 12mm lens i shoot 34 per exposure or with the 10.5mm fisheye i shoot about 11 per f-stop.

 

 

Not understanding this step. Are you saying for a single position you merge 34 pictures or 34 positions or something else?

 

 

for the hdr merging you can use either HDRshop, photomatrix pro, or photoshop.

 

 

What format are your originals? RAW? JPG? and what format do you save to once they are merged (in photomatix for example)? Photomatics does not let you save as hdr format.

 

Sorry, I told you I was a basket case when it comes to this stuff...

[chris erskine]

I shoot 3 rows of 10 at +45 0 -45 then 2 at +90 and 2 at -90.

 

i could shoot less at +-45 but i don't want to change tripod settings while shooting.

 

so thats 34 photos that need to get stitch for a 360 photo.

i then do that 9 times for each of those positions.

 

thats about 300 or so photos per hdr sphere. i can take 2 of those in RAW with a 12gb card.

 

as far as formats go i think EXR is a lot better than *.hdr it works way faster. and the 16bit float is supposed to cover something like 30 f-stops with 32bit around 256. but you should probably test that out.