PDA

View Full Version : HDRI creation/Camera RAW files....did I do it right !?

mushroomgod
07-19-2007, 05:15 PM
Hi Guys, I posted this over on the vray forums, but i thought Id post it over here to :)


oh, and this is the first time Iv done this so if Iv done this wrong or missed somthing. could somone please tell me! And I realize this is not the best way to make an HDRI, and its not a true HDRI...but its easy and quick http://www.chaosgroup.com/forum/phpBB2/images/smiles/icon_smile.gif

so......
Last night I took an enviroment shot of a local church, I took the shots on raw format, I took about 6 horizontal and 1 up 1 down with a fisheye lens.

The files where then converted to 16 bit tiffs and stiched using PTGui, and then saved out as a 16bit ps file.. The final 16bit PS image is the top image..

Then in Lightroom I made a bunch of exposures - the 7 images in ther middle, these where saved out as 8 bit jpgs.

Then in HDRISHOP I combined all the different exposures and made a single HDRI file...it is the image at the very bottom (note it looks very similar to exposure -2, but looking at them in photoshop revieals more information in the 32 bit hdri)...also, I was expecting it to look like exposure 0...did i miss somthing?

http://www.mushroomgod.com/hdri/hdri-test-run.jpg

also, here are some rendered examples, showing a test car, with 8bit and the new 32 bit reflections...to me atleast there more info in the 32 bit, and looks less flat.



http://www.mushroomgod.com/hdri/cars-hdri.jpg

http://www.mushroomgod.com/hdri/range.jpg


Anyway...have I missed anything...what (if anything) did I do wrong, and what are youre thoughts?


if anyones intrested...heres the low res hdri file.
http://www.mushroomgod.com/hdri/test.rar

and a QTVR
http://www.mushroomgod.com/hdri/localchurchsmall.mov
mushroomgod
07-19-2007, 11:52 PM
heres another test, same as before....exposures genrated from 16bit tiffs generated from 12 bit raws..

1st car is the 8bit enviroment only

2nd car is the same 8 bit enviroment with 2.2 gamma applyed

3rd is the pseudo-hdri, no gamma applyed just raised the output to make it look like the original exposure.

http://www.mushroomgod.com/hdri/carpark.jpg

the 8bit 2.2 (No2) one is pretty close visualy to the pseudo-hdri (No 3), but the hdri still has more range, and oddly the colours are more acurate, the 2.2 is a little over saturated.
Sandstorm
07-28-2007, 12:33 PM
Very interesting and useful thread. :thumbsup:

Can this result also be achieved by using freeware tools like pfstools?
http://www.mpi-inf.mpg.de/resources/pfstools/

Best regards,
Martin
Kender
07-29-2007, 03:10 AM
hi,
as I saw, your extrem pictures are to bright, for the darkest one, and to dark for the brightest one.
The darkest picture needs to be almost black, to give to your hdr panel the very dark values.
The same for the brightest, but at this oposite :)

Anyway, I just read deeply your post and, if I understood well, my english is not exellent, you didn't take several picture with differente exposure but you did thel in your labo.
I guess it is a source of problem because, when you do them in labo you cannot create extreme values. You need to have under exposed photo to give values of extrem lights, like the sun behind clouds.

You should take your time and take 7 or 9 photo of the same point of view and see what HDRshop makes with them.
I hope that will help you.

I ll try to find back the debevec course from the last siggraph. Maybe some more tips in it ;)
Enjoy,
KEnder
CGTalk Moderation
07-29-2007, 03:10 AM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.