The Images and Moving Pictures (Technical) Thread

[Mattmovies]

This thread is for image sharing and the technical aspects of visual art forms. This is an exciting time to see what techniques are being perfected in garages and basements across the world.

I'll start the conversation with HDR photo and video.

Years ago, in Spengler's Forum, I had discussions on photography primarily with Jiaogulan, Petroamerica, and Geotima. At one point, Geotima brought up HDR photography, which I had never heard of.

Examples:






Each of these images is made up of multiples. You have to bracket the exposure or adjust the shutter a stop for each picture. Then you use software (I use photoshop) to combine the images to allow for extra detail in the highlights and shadows. As I remember Geotima was really into this style, Jiaogulan wasn't into it ( for reasons I respect, he was into film and felt these images were too painterly and untruthful, or because he's German and digital is like using an automatic transmission: it's for sissies), and Petroamerica encouraged any experimentation at all (he's a master photographer of the old school, and he was using a camera phone in circa 2006 to take crazy awesome images). I was interested in HDR primarily because I felt it was something digital photography brought to the table that would be nearly impossible to mimic with film (at least there is that computer component either way, and I don't know that this could happen chemically).

I was also interested in the possibility that it could be done with video. I went to my film professor in January 2007 and asked him if it was possible to create HDR video. The answer: HD?? Clarification: No High Dynamic Range... um... like the photography. Clarified answer: *smiles* Sorry, I don't know anything about that.

Clearly the HDR thing hadn't crossed much into the video world. I thought on how this could be done and couldn't fathom the answer. First, the shutter on a video camera is a constant that can't move, so if you have a 30 or 24 frame per second image, you can't change that. You'd have to change the aperture. But how would I get multiple identical images in a shot, especially with people?

It looks like I've got an answer today: They used a beam splitter and two cameras:

The quality is sort of like you might see in a video game. It's very painterly. I don't think it necessarily imitates the eye, but the detail in the latitudes of the image is vaguely similar. It's a good way to mimic how our eyes have such a huge dynamic range and attempt to fill in some extra detail. And in some ways its like shooting with black and white in that you can really play with what colors are on the set. I wonder if it would be better to use clothing that was less "busy" and distracting?

They are using two Canon 5D mark II s:

The latest trend in indie film and video is to use one of these new HD digital SLR cameras that record HD video. I got a different model recently and love it.

[Tinker]

My friend does HDR. What I would like to do is figure out a way to do HDR video. One of the things I was thinking was of having a camera take three photos in sequence for the HDR sequence but have people moving through, so that the motion is caught in three different color schemes, but they don't line up perfectly, so that even a still implies motion. So twenty-four bursts of three in a second.

[Mattmovies]

Getting a camera to operate that quickly and to program it to bracket the exposure in that sequence would be a challenge. The guy at the link (its a bit buried ) for the HDR video built a rig and used two cameras, but he hasn't shown the rig to the public yet. He uses a beam splitter on a lens, then the light from that lens bounces to each camera with the same image, but the cameras take them at different shutter speeds. That way you get an under exposed image and an over exposed image that combines to an HDR image.

The cheapest camera I can think to use would be the Canon T2i (runs about 895 with kit lenses). Most video cameras don't allow for adjustments on shutter speed, but the T2i does on its HD video setting. You'd have to have two to do it by that method though.

[Mattmovies]

There are cameras on the horizon that will have this built in, though, probably using the method you're mentioning. The RED scarlet will, but its going to be expensive. The feature will certainly move to cheaper models of DSLR.

[Colonel Sun]

[Tokyo]

Not my work. Anyways, an interesting thread. Will read up on HDR.

[Colonel Sun]

[noddy]

Stunning pictures (the HDR ones)

Ive got a cheapo DSLR (bottom of the range canon eos) that ive been using to re-learn photography after many years, and im still frustrated with my lack of skills!

Im sure I saw something simmilar being done with FFT filters during my computer generated art fetish period, will have to chase it up.

[Tinker]

I have an older DSLR too. Mostly been using it to take photos of campaign events. I need to get into it a bit more deeply.

[Mattmovies]

If you're diving into DSLR photography, two things to play around with and get used to are ISO controls and white balance. Those are two settings that aren't on film SLRs (ISO was chosen by film selection). White balance can often be easily set by placing a piece of white paper in the light you are using and taking a picture of it, selecting that as "white" and allowing all the the other colors to follow suit. Otherwise there are pre set settings for white balance that can work pretty well. DSLRs are the easiest device to use to learn photography because of the instant result and manual features.

I've been playing around with old lenses on my camera. I have an adapter that I use to connect my old Olympus OM lenses and an old 1950s Hanimex telephoto lens. The only disadvantages to using old lenses is the lack of autofocus and auto aperture. The old lenses sometimes have an unusual "feel," are built of metal rather than plastic, and you can find them in thrift stores and online for cheap to reasonable prices.

[Nonc Hilaire]

[Colonel Sun]

For anyone interested in HDR, fast bilateral [gaussian] filtering for tone mapping is probably of interest.

http://en.wikipedia.org/wiki/Bilateral_filter

http://people.csail.mit.edu/sparis/bf_course/

By coincidence, have been reading about this topic this past weekend for an entirely unrelated reason.

[Colonel Sun]

from



Software solutions for dealing with the unwanted



halo effect:

[PDF slides with some impressive results]

Good explanation of the method with only minimal mathematics.

[Mattmovies]

Another type of photography that is interesting is the tilt shift lens variety.


The lens can tilt in various directions out from the camera. At extremes, the effect makes real life look like it was created with miniatures. Here's some examples:




I'm usually pretty good at figuring out special effects, but when I saw this type of footage for the first time, I was bewildered. I felt like a kid again.

[Colonel Sun]

The 3D illusion is striking. However, I wonder how one could reduce the jerkiness of the images. Probably a faster sampling rate.

[Colonel Sun]

I thought that this 3D anamorphic illusion [simulation] was impressive:

http://vimeo.com/1496857

[Mattmovies]

The jerkiness is intentionally manipulated in post production. The guy that shot the footage changed the frame rate to mimic old stop motion movies, to make it appear as though the cars were toy cars and the people were animated, but they were in fact real people. One of the tricks of shooting miniatures is to keep the depth of field narrow, to make miniatures more life like. He's creating an illusion of that practice.



That hologram is interesting and reminds me of new alternate reality programming. I'll see if I can find more to post on that soon.

[Tinker]

[Rhapsody]

[Colonel Sun]

[Mattmovies]

Colonel Sun,
Here's an example of augmented reality:
There are aps that are already happening on the iphone to mark location and such in the real world. A camera device sees a symbol and adds a layer of 3D augmented reality to it. That's what your video reminded me of.

Here's a video by Keiichi Matsuda to simulate a world of augmented reality:

[Colonel Sun]

[Colonel Sun]

[Colonel Sun]

[Rhapsody]

[Colonel Sun]