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-   -   Moving HDR images..? (https://www.dvinfo.net/forum/alternative-imaging-methods/141358-moving-hdr-images.html)

Biel Bestue February 19th, 2009 09:25 PM

Quote:

Yes alot of pro photographers use a single-exposed raw 16-bit
strange when hdr images can go up to 64 bit images!

Raw doesn't have to mean more latitude but non-debayered image

Nicky Campos February 23rd, 2009 02:31 AM

Quote:

Originally Posted by Craig Bellaire (Post 1014674)
How about using HD usb web cams and capture all at once?

Great Idea but is it possible to capture simultaneously with many cams and be synch-locked?... with one capture/pc station?

Also the cameras cannot be in the exact same place can they?

This would be really cool if someone could assist... even for stereo/3d parallax?

Craig Bellaire February 23rd, 2009 07:22 AM

Web Cams
 
With this software
| NORPIX | DIGITAL VIDEO RECORDING SOFTWARE

Yes you can record multiple cameras on one computer... Or use IP cameras and record using gigabit crossover cable straight to the computer... No Encoding just capture the stream just like using a USB HD TV card...

And for the offset, get the cameras as close a possible in a rack or mounted on something, check all the levels and make sure they are as close as can be, shooting straight, then over shoot and realign in post and crop...

Anyway that's what I've been pondering on....

Karel Bata March 6th, 2009 11:18 AM

I'd much rather use a single camera, which is why I'm going to try some experiments with film. Unlike video, modern film stock has a lot of info 'hidden' in the latitude. it is in fact an HDR capture medium already, but any photographic paper, or monitor, that was set to flatten out and display the whole range would look very, er, flat.

I've just tried something with an old stills negative: Use password 55555 to see the images

The first pic shows how a 'normal' print from the neg would look. Unimpressive. Burnt out sky. By altering the light setting on the flat-bed scanner I produced the next two stills which pulled out the information previously hidden. I then combined them in Photomatix.

The result was a bit flat so I tweaked the contrast - which is what you'd do in post anyway. (And I must confess -naughty me- I also fixed the scratches because they really bugged me)

Not bad methinks for a first attempt with the settings in Photomatix left in their default. The important points are 1) this is from only one camera exposure and 2) using regular domestic Kodak stills stock. In other words, all done in post. With video you would need 3 seperate camera exposures to get this (or something like a Dynamax chip) but with film you can do it in one.

Which means, with the right software, you can do it with live action in DI. However, that's a bit out of my budget right now...

Thoughts...?

__________________

Nicky Campos March 7th, 2009 01:14 AM

I like that Karel!!!

I have a friend who has done this same thing... although I dont see any extra latitude in the shadows though? Is there anything else in there?

Damnn I wish film were more affordable - the HDR look isnt well suited for shallow DOF of 35mm sized format... so Im thinkin a good 16mm stock equivalent could be cool???

What ya think of 16mm for single-exposed HDR? A guy once told me he could put a 16mm rental package together for the same price as a good 2/3rd inch HD camera package??

Karel Bata March 8th, 2009 05:26 PM

Glad you like it Nicky. Yes, it looks very good for a random image!

Still a few problems to crack. Like
how do you get the negative sequence into a computer without a proper telecine? And scanned three times at different light levels! That's a lot of scanning.
Film speeds are never exactly as they say so optimally you need to do a clip test for each film batch to establish what the speed really is.
And it could be the film exposures have to be spot on for it to work - or at least incorrect in the same way on all the shots within a sequence or you may not get a good match.
And then there's the amount of time it takes to scan it all in and process it!

I reduced the images from my original 35mm scan to 1280 and it then took Photomatix about a minute to process (in batch mode that would be half an hour for a second of film!) I then shrunk them to the size you see on Photobucket.

I think Super-16 should work fine. Regular 16 might be a problem with grain - the HDR may accentuate it. Might be nice though. Again, more tests. I'll see if I can dig out some old 16mm neg.

I've also tested using only two scans, which would lessen the workload, but that didn't come out too good, but maybe it's a case of finding the settings' sweet spot. There's a lot of stuff on the net that's been written about HDR, so now that I've established this approach works in principle I ought to do some serious RTFM.

Will continue doing tests though with old negs taken in different lighting conditions and post links here.

:-)

Karel Bata March 23rd, 2009 01:39 PM

Here's some more experiments I've done with still images taken from film negs and then digitised at different light settings (you'll need password 55555 )

And an interesting allied link: Work with natural light in HDR
"It’s a common yet mistaken assumption that the only
Adobe® After Effects® Professional users who have any
business using 32-bit mode are artists working on bigbudget
blockbuster films. The reality is that anyone
using the Professional edition can benefit from the
32-bit float High Dynamic Range (HDR) pipeline."

Karel Bata November 15th, 2009 05:43 PM

Well it seems that Arri may have beaten me to it!

Arri's new cameras Everything is about to change... according to an article in High Definition magazine have a 'magic' trick up their sleeve:
  • "The key to the increased performance is what we call ‘Dual Read Out’ – we have on the sensor 32 output channels and we read every pixel twice through a normal gain and through a high gain. Each of these read outs happens in 14 bit depth. We then combine them and get 16 bit pixel depth for every pixel element. So that results in a very quiet image with very low noise. This is a philosophy which is similar to our scanner with its double flashing, however these read outs are happening at the same time.”

    "Arri promise more ‘magic’ to do with this heavy processing which may be to do with HDR or High Dynamic Range as its known in stills photography. This is where you combine several different exposures into one, taking the best exposure elements from each to make a extraordinary image. Could this be what Arri have in mind?"

Well, if Arri aren't thinking that, other folk clearly are, and tonemapping software is now well established and it wouldn't be too difficult for a programmer to adapt it. Photmatix (the standard in stills hdr software) are going to kick themselves for not looking ahead and making their software available as an AE plug-in. I wrote to them about it, and they said they had no plans. So someone else will do it, and it'll be the next Big Thing.


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