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Sphere♥
02-12-2005, 10:07 PM
I was placing bright panel objects around my scene to recreate studio lighting, works well, but can take time. Then in a search on the internet for studio lighting I came across HDRI Studio (http://www.hdri-studio.com/). Very nice HDRIs there to recreate high-resolution studio lighting. Using image based lighting for studio lighting is a great idea but I though that for scenes without mirrors, high-resolution probably isn't necessary. So as a test, using a simple brush in a paint program, I painted lights on a 1400x690 black canvas. I don't have an HDR paint tool, so I saved it as a simple jpeg and increased the color gain in maya. It's fast and cheap and probably would look good if I spent more than a few seconds on painting the lights :thumbsup:.
Link to sample image... (http://www.geocities.com/grotata/) (newbies can't attach:sad:)

floze
02-13-2005, 03:59 PM
There's a big difference between a .hdr (or any floating point capable format) and a jpeg.. that's why it's called hdr (high dynamic range), not ldr (low dynamic range). Dig into Paul Debevec's site to get an understanding for it:
http://www.debevec.org/

WhiteRabbitObj
02-13-2005, 04:36 PM
Basically you're just texturing the Final Gather color by doing your method. Which, in essence, is really all HDRI is as well, but you lose a lot of intensity information since HDRI has a much wider range. Realistically though, for many applications, ldri is probably sufficient and faster.

TomD
02-13-2005, 10:30 PM
:scream: Hahah those hdri studio guys maybe they know something about studiophotography and heard something about HDRI but selling HDRI photos of studiolighting ??? :scream: Sphere, you just undermined their whole business plan, with a simple brush in a paintprogram. :D

Floze, WhiteRabbit, for a studiolight setup is hdri just overkill, there would be too much equal floating point values in a hdri (A softbox is just a plane that emits the same amount of light from corner to corner)
I would have to agree with you, if you want to integrate a 3D object in a real environment, filled with subtle shades and bright spots, than nothing beats a real environment-hdri.

Sphere, you mention that it takes more time if you use bright panels. Do you mean longer rendertimes? I could live with that, then I'd get the extra flexibility of quickly placing my lights wherever I want.

floze
02-13-2005, 10:46 PM
:scream: Hahah those hdri studio guys maybe they know something about studiophotography and heard something about HDRI but selling HDRI photos of studiolighting ??? :scream: Sphere, you just undermined their whole business plan, with a simple brush in a paintprogram. :D
Without judging anything, cause I havent ever seen a sample of one of their HDRIs, but:

#Out of their FAQ

Q: What are the advantages of using your HDRI environments over just using standard lights?

A: The lighting available from our maps is based on a live photographic studio scenario where the photographer set up the lighting and balanced the exposures. Photographers approach lighting in a fundamentally different way due to real time feedback of the light interacting with the objects. The photographer's lighting skills are, in a sense, built into the maps as opposed to you having to create a virtual set-up yourself.

The keyword is: exposure

TomD
02-14-2005, 02:23 PM
My reasons why I don't like Studio HDRI are two fold.

For the better part of my career I've been a studiophotographer and I've done in real life what hdri-studio.com attempts in 3D with their hdri and those are packshots.

If someone makes a hdri of a light setup, well balanced exposures and based on an actual situation then you have a nice picture of a fixed lightsetup... even with similar objects, not once have I made an excact same lightsetup. To get a fine line of reflecting light to accentuate a knob, for example, I'd always have to move only one softbox and/or adjust its lightintensity.
What they sell are fixed lightsetups. That's the artistic reason why not to use hdri for studiolight setups.

Photostudio walls are often painted black or dark grey, to avoid secundary or unwanted reflections. And softboxes are just lights with a difusor in the form of a square, rectangle, cirkel or hexagonal. So what a hdri would capture are, in the darkest areas: studio walls (that you don't want to show in your rendering) and the brightest areas: a bright shape. Between the brightest light and the studiowall? ... there is a backdrop that I prefer to make in 3D.
So the only thing I'd realy need are the values of the bright shapes. Those values fit perfectly in a Normal-dri, if not bright enough there is color gain. So that is the technical reason why not to use hdri in a studio environment.

It's just that when I saw what hdri-studio are selling made me laugh until I saw their prices (for a single hdri, between 20$ and 375$ depending on resolution and license) that just made my stomach turn, a plain ripoff I'd say. Especially if you look at the nice results of Sphere's quick doodle. (I'd still advise to use independant, bright panels over one big texture though)

In my opinion hdri can only be used to its fullest extend in outdoor environments where you want to capture wide range of lightinformation and fine details, for reflecting in your 3D object.
...its just a humble opinion.

PeterCrowther
02-14-2005, 04:35 PM
Hello gentlemen,

First, I am the developer of HDRI-Studio (http://www.hdri-studio.com/)
So I have to declare my interest in this conversation you are having here.
I hear you opinions and some concerns over costs.

No pack shots on the site, just simple models created in Maya and rendered in Mental Ray.
All the images on the site are unretouched, straight from the render, with minimal set up time
using only the files we sell to light the scene.

The HDRI-Studio maps can be used for far more than just virtual pack shots.
We have very wide ranging customers from all over the globe who got the idea quite quickly.

We show interactive previews for all the images we sell. You only buy the file or files
you need instead of a mixed bunch bundled on CD. In our own tests, you only need
low to mid resolution files for good results at high resolution rendering. Each file has
been designed to be flexible, creating a large number of possible outcomes by rotating
the enviromment about the vertical axis. (See the "open preview" buttons
on the product bars on the order page. Mouse over the 'rotate' to see the lighting
effects change by rotating the environment).

So, for as little as $20 you can get a professional lighting set-up that can be used
over and over again on many different jobs. And, unlike a landscape or interior image,
you can re-use it in such a way that your client never realises that the same map was used.

We have tried to keep the costs lower for smaller companies and individuals.
This is I think a fair way to do business.

You get what you pay for. These files were not cheaply produced. We took
no short cuts on quality, and great care in what we were after.

You are of course entitled to form your own opinions.
Try one out, and see for yourself. Otherwise it's a bit like reviewing a film
without seeing it, not very convincing...and certainly not accurate.

Best regards,

Peter Crowther

Sphere♥
02-14-2005, 10:19 PM
Hi guys, just want to make clear that I wasn't saying what I did "is just as good as..." or anything like that. Simply was surprised by the results of a few seconds (literally) of paintbrushing a blank spherical map. And yes Floze, more control over the lights would be achieved with an HDR paint tool (and a rectangle tool ;)), but I mentionned I didn't have one and the results without aren't bad. TomD, no, I don't think longer render times (not noticeable anyhow) and yeah, you're right, definitly more control with moveable light objects. I guess I meant it takes time to set them up (lazy as I am). I just thought I'd share the simple idea :) . PeterCrowther, nice product, albeit I agree it's a tad expensive. I guess you need to cover the costs of the SpheroCamHDR camera! (<envy>)

TomD
02-15-2005, 09:43 AM
Oooh this realy is a popular board. Mr Crowther himself cares to join the discussion.
...Try one out, and see for yourself. Otherwise it's a bit like reviewing a film
without seeing it, not very convincing...and certainly not accurate...
True, seeing is believing. So Mr Crowther my question to you is, do you have a sample hdri that I can use to play with? Perhaps with a red cross painted over the map.
Than maybe I could write a more objective opinion about hdri's captured in a studio.

PeterCrowther
02-15-2005, 10:21 AM
Hello TomD,

It's great that you thought the images on the site were real pack shots.
This from a real life studio photographer is very good to hear.

We do have some low res demo files on the CD attached to the current issue
of 3D World magazine. These are very low res but are good enough to test
and get a feel for how they work. This, along with a special discount offer should be
enough to evaluate the files and move onto the proper commercial ones.

There are a couple of independent reviews and some other more in depth ones
in the pipeline. 3D World reviewed it in the previous issue, 61. Metin Seven reviewed it
on his site http://www.metinseven.com/review_hdri-studio.htm


Cheers,

Peter

floze
02-15-2005, 04:18 PM
Metin Seven reviewed it
on his site http://www.metinseven.com/review_hdri-studio.com

'Fixed' that link ;)
http://www.metinseven.com/review_hdri-studio.htm

PeterCrowther
02-15-2005, 04:27 PM
Thanks Floze,

As I am new here the delay in posting is making it tricky
to see if I got the info correct first time.

Cheers,

Peter

Sphere♥
02-23-2005, 06:18 PM
If anyone is interested just before leaving last night I set up a simple scene using this lighting to test FG animation in 6.5. If only the camera moves, with FG Rebuild off I get good quality and low flicker with low FG rays. With moving objects (FG Rebuild on) the FG rays must be much higher to reduce flickering. This simple animation is using no lights (no GI), 1000 FG rays, slightly increased min/max radius, seconday diffuse bounces on (1,1) and anti-aliasing contrast threshold lowered to avoid aliasing on monochromatic (white) cubes. On a single AMD CPU PC it took just under a minute per frame with 500 frames taking eight hours.
1MB Xvid avi Animation (http://www.geocities.com/grotata/BallDominoesL.avi) hosted by geocities on same page as image above, so it may exceed download limits first few days. Note that mpeg4 compression noise is probably contributing to the flickering, but there was flickering in the raw animation frames. I have a higher quality Xvid, but it's too big to post.

Cheers.

PeterCrowther
02-23-2005, 07:05 PM
Hi Sphere,

Yes, it looks good. Mental Ray in Maya 6.5 is a real improvement over version 6.
Secondary diffuse bounces really does add some warmth that previously
required a lot of photons...

Good test. Thanks for sharing.

Cheers,

Peter

Sphere♥
02-24-2005, 12:23 AM
I've put up a mirror of the 1MB Xvid avi animation (http://www.putfile.com/media.php?n=BallDominoesL&width=640) trying out putfile.com. You can double-click on the embeded animation there to view full screen (well, for Windows anyhow).

rodrigogua
04-07-2005, 12:25 AM
@ TomD: the charm in their products is that they ARE based of real-world studio lighting set up by PROS. it says so in their ads anyway. the idea is that they had a lighting profesional to set all these lighting rigs for them ina dark room, took an HDR Spheron camera and got super-high-res hdris for use in the CG industry. do you think they'd still be on business if their products were false? i think lots of CG professionals have used their products to get quick, proffesional lighting setups real fast and with virtually no effort. their images ARE high dynamic range, so somw of the lights actually emit a more intense light than others. beleive me, i've gone through their documentation and studied their products in my attempts to recreate them in an entirely CG way. you can have a look at one of my attempts here. The one thing that i didn't consider when recreating it is that MR is not capable of creating an unclamped output, so the image in that thread is actually LDRI. You can still set the brightness of the image, but all of the planes are equally bright, which is the whole matter when it comes to HDRI

Hope this helps clear up the whole matter.

ulei
04-07-2005, 10:23 AM
you can get the same results with just painting those pictures in LDR and set a colorgain. just as the first poster said - i worked with that in a few projects, and the imitation of studio-environment worked perfect.
HDR makes no sense, because it would have just an minimal falloff to the edges of the light in its intensity ...

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