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Unbounded High Dynamic Range Photography Using a Modulo Camera

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Re: Unbounded High Dynamic Range Photography Using a Modulo Camera

#71
post #65
post #52

Earlier quoted context omitted.

https://twitter.com/ICCP_2015/status/592403545468448768/phot...

That's a picture. Where's the paper?

Here's the paper link: http://www1.cs.columbia.edu/CAVE/publications/pdfs/Nayar_ICC...

Re: Unbounded High Dynamic Range Photography Using a Modulo Camera

#73

> No more will photographers or even ordinary people have to fumble with aperture size and exposure length. This is a "computer scientists" understanding of photography, and this phrase alone can even be seen as "dangerous" by photographers. There's more to aperture size and exposure length than "how much light reaches the sensor", like focus, depth of field, motion blur and bokeh, to name a few, that is not aknowled…

> This is a "computer scientists" understanding of photography, and this phrase alone can even be seen as "dangerous" by photographers. The actual headline of the article is actually more informative and less misleading than the subhead: "Unbounded High Dynamic Range Photography Using a Modulo Camera" In photographer's terms, they're referring to ending blown highlights (caused by filling the wells in a sensel) not s…

[deleted]

Re: Unbounded High Dynamic Range Photography Using a Modulo Camera

#74
post #61

Earlier quoted context omitted.

Yes, that's what modern cameras with the built in feature do. (although I'm not sure about 8 times) The article talks about this feature.

Yes, but why can’t the camera do it continuously? Film at 240fps and provide a 60fps output with 10bit color depth.

Because the images would look funny. Imagine you're capturing someone running - at frame 1, they would be at position x, and at frame 2, they'll be at position x + 1. If you try to stack them together, you'll get a weird ghosting effect.

Re: Unbounded High Dynamic Range Photography Using a Modulo Camera

#77

Looks to be more related to exposure than saturation but still, it's an interesting new take on dynamic range. I'm more a hobbyist than an expert but current tone mapping techniques (at least anything mostly automated) can often leave you with "halos" around objects where the software has feathered the edges between lighter and darker areas. Then the article mentions the issues with using multiple shots for tone mapp…

Halos are a problem, but they can mostly be removed with good post-processing. Note they're not a fundamental aspect of tone mapping. Tone mapping is just whatever algorithm you chose to compress the HDR information into a low dynamic range we have for displays. The great thing about this camera compared to multi-exposure HDR (apart from the halo effect you mentioned) is you can actually take pictures of moving objec…

Out of curiosity, with regard to video, what would be the difference between what you describe and a nicer version of the sort of processing used in (for example) some Axis security cameras? I guess the current method is just to capture a decent range and then process each frame to boost the gain on shadows and lower the gain on highlights, right? Sort of an extension of quick-and-dirty HDR on still photos.

Either way, this is the sort of stuff that has always interested me about photography and videography. The creative aspects are obviously the end goal for most people (myself included) but I've always been a sucker for the technical aspects of it...the craft to the art as it were. Nothing prompts me to pick up my camera and shoot some photos or some video like learning about some new tool or technique that I want to try out. It may be the mark of the eternal amateur but still enjoyable.

Re: Unbounded High Dynamic Range Photography Using a Modulo Camera

#78
post #76

Can somebody explain how this design differs from existing self-resetting pixel designs?

I'm not sure what you mean by self resetting pixel designs. Do you perhaps means the self-shuttering (rolling shutters) on CMOS sensors?

This is very different. If you oversaturate either a self shuttering sensor or a shuttered CCD, that information is gone. All you know is that this is "100% bright, or more". Your software which turns raw sensor readings into an image makes the area full brightness, and you get blow outs.

With this approach, say the light is bright enough to make a pixel read 567% (if that as possible). A standard sensor would record 100%. This sensor would empty itself five times and record 67%. Then, the algorithmic magic happens which looks at neighboring areas and figures out how many roll-overs happened and adds the 500% back in.

You can't do that perfectly (hence my comment before about an overexposed zebra), and it will introduce new forms of aliasing, kind of like de-bayering the bayer masks makes moiree patterns.

Re: Unbounded High Dynamic Range Photography Using a Modulo Camera

#79

> No more will photographers or even ordinary people have to fumble with aperture size and exposure length. This is a "computer scientists" understanding of photography, and this phrase alone can even be seen as "dangerous" by photographers. There's more to aperture size and exposure length than "how much light reaches the sensor", like focus, depth of field, motion blur and bokeh, to name a few, that is not aknowled…

I'm surprised no one in the comments so far has used the word "clipping", which is what the real breakthrough here is in. I've been doing street photography somewhat seriously for about five years now, and always shoot full-manual: I rarely have problems with motion blur because I control the shutter speed; I rarely have problems with focus because I use assisted manual; the only thing that gets me with any regularit…

Being about year in with street photography this is very insightful. Can you elaborate on any tricks you do in Lightroom in this area ??

Re: Unbounded High Dynamic Range Photography Using a Modulo Camera

#80

> No more will photographers or even ordinary people have to fumble with aperture size and exposure length. This is a "computer scientists" understanding of photography, and this phrase alone can even be seen as "dangerous" by photographers. There's more to aperture size and exposure length than "how much light reaches the sensor", like focus, depth of field, motion blur and bokeh, to name a few, that is not aknowled…

> This is a "computer scientists" understanding of photography, and this phrase alone can even be seen as "dangerous" by photographers. The actual headline of the article is actually more informative and less misleading than the subhead: "Unbounded High Dynamic Range Photography Using a Modulo Camera" In photographer's terms, they're referring to ending blown highlights (caused by filling the wells in a sensel) not s…

> There's a school of photography that basically lives and dies by over-saturating images (e.g. http://kenrockwell.com ) and they'd likely have a cow over the headline, but understand and be totally onboard for the actual goal.

Actually, I suspect that even that crowd, after the initial shock would be absolutely on board. This would mean that no longer would the sensor control how the high-end clipping happens, but now that could be tailored specifically via a post-processing filter. E.g. to exactly match a long-gone film emulsion's behavior, "enhance" a classic, or to simply to create new clipping functions.

This is a bit analogous to the flexibility that black and white shooters gain by working with modern color sensors. When shooting B&W film, the tonal result was controlled via a combination of the film's spectral response and any colored lens filters applied, the latter used to manipulate tonal contrast between different colored subject matter (e.g. sky, plants, skin tones, etc.). Now a skilled photographer can shoot color RAW w/ B&W preview (for a preview of the image luminosity) then adjust in post to nail the image effect without having to mess even thinking about what colored lens filter(s) to have used.

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