October 21, 2014, 04:46:02 PM

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Messages - Lee Jay

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46
EOS Bodies / Re: Multilayer Sensors are Coming From Canon [CR2]
« on: October 12, 2014, 01:07:19 PM »
I'd jump to buy a camera that had a max ISO of 100 and 1 fp 10 seconds if it offered better resolution and DR.

Get a 7D Mark II and a Gigapan.  In 10 seconds, you can shoot something like a 9 shot panorama with a 5-shot bracket at each spot.  That should get you 16+stops of DR and 115 megapixels.

47
EOS Bodies / Re: Multilayer Sensors are Coming From Canon [CR2]
« on: October 12, 2014, 12:34:05 PM »
I meant with an IR-modified camera or for example with the 60Da

Oh...in that case, roughly the same (give or take a stop or two - not orders of magnitude).

48
EOS Bodies / Re: Multilayer Sensors are Coming From Canon [CR2]
« on: October 12, 2014, 12:00:40 PM »
A few questions pertaining to the usefulness of capturing IR data in a separate channel:
1) Can humans see InfraRed?
No.
Quote
2) How much of the IR spectrum can be transmitted through DLSR lenses?
All of the near IR spectrum.  But little gets through the sensor's IR filter.
Quote
3) Can you gain added colour accuracy by sampling additional channels which overlap with wavelengths outside human visual perception?
I doubt it.
Quote
4) For a given ISO and Aperture, what is the difference in exposure time needed to create an IR image vs a visible light image?
With the IR filter, orders of magnitude

49
EOS Bodies / Re: Multilayer Sensors are Coming From Canon [CR2]
« on: October 12, 2014, 11:40:30 AM »
Your rendering demosaiced data, which doesn't necessarily require the constant memory space.

Yes, it does.  When you're in the Develop module of Lightroom or using Camera Raw, the entire 64 bit per-pixel image is in memory.  The rendered view is on top of that.

50
I have DR problems a lot but that's because I get only get 7-9 stops of DR in many of my shots because so many are at high ISO.

If I had my choice, which I don't because of the quantum nature of light, I'd rather have two more stops of DR at high ISO than at low ISO.

51
EOS Bodies / Re: Multilayer Sensors are Coming From Canon [CR2]
« on: October 12, 2014, 08:51:47 AM »
Quote from: dgatwood link=topic=2316channel 1932#msg4channelste=1413081039
It would also be a tremendous amount of data, and a lot more data to be factored into image processing. Five layers at 25megapixels is 125megaphotodiodes. At 14-bit, that's around 235-245 megabytes per image. RAW editors would also have to add the right kind of support to utilize those extra layers.

Even three layers would be unworkable uncompressed at 25 megapixels per layer.  It's hard enough to deal with 25–30 megabyte image files, much less four times that.  They're clearly going to have to come up with a good lossless compression algorithm.  A lossless scheme similar to PNG should get you about 2.7:1 compression, which means about 81 MB with all five layers included, or 49 MB with only three layers.  But I think it is possible to do better than 2.7:1.  After all, the high order bits of nearby pixels are likely to be fairly similar except near high-contrast edges, and the more bit depth you have, the more identical bits you'll probably have.

Storage space probably isn't nearly as big a concern, as yes, you can compress the files. However when your working on them, you need the full pixel data. It's like opening a large 16-bit or 32-bit TIFF in Photoshop...if you look at the memory usage, it is usually several hundred megs.

So what?  When you're working in Lightroom or Camera Raw you're working on demosaiced data anyway at 16 bits per channel for four channeks.  The size is 8 bytes * pixel count.

52
I wonder if Chipworks will dissect the 7D II sensor. It's been a long time since they dissected a Canon sensor...

Not so.

https://chipworks.secure.force.com/catalog/ProductDetails?sku=CAN-EOS-70D_Pri-Camera&viewState=DetailView

For $16k you can find out everything you want to know.

53
EOS Bodies / Re: 7D2 theory
« on: October 10, 2014, 04:58:17 PM »
To produce stunning images, a professional doesn't need to understand the science of light, they just need to know what works for their images.

Understanding the science would make them better.

54
EOS Bodies / Re: 7D2 theory
« on: October 10, 2014, 11:57:25 AM »
He was talking FILE SIZE.

Then why did he say, "megapixels" instead of "megabytes"?

55
EOS Bodies / Re: Multilayer Sensors are Coming From Canon [CR2]
« on: October 09, 2014, 03:45:59 PM »
I wonder if it would be helpful to have a quasi-bayeresque multi-layer sensor.

So instead of having every pixel being constructed with what I assume would be a B/G/R construction, they decide to have some interspersed pixels with other channel arrangements. (e.g. R/G/B)

Personally, I like Panasonic's color splitting technique. It still preserves all of the light, but it has W-R and W+R pixels (white plus/minus red, which ends up being "bluish" and "reddish" pixels in the end). It doesn't filter at all, it just splits the light coming in and directs some component of it (red) to different pixels. It's supposedly 100% transmission (probably not exactly, 99.something%), and 2-3 times the sensitivity of bayer sensors (which should mean it's far more sensitive than a layered sensor, with high dynamic range and color fidelity:

http://image-sensors-world.blogspot.com/2013/02/panasonic-develops-micro-color-splitters.html

Di and Trichroic filters have been used before, most notably in "3 CCD camcorders".

Sure, but those were pretty bulky, with three full sized sensors. This is a fully integrated per-pixel solution.

You saw this?

http://www.dpreview.com/articles/6555348105/nikonimagesensor

56
EOS Bodies / Re: Multilayer Sensors are Coming From Canon [CR2]
« on: October 09, 2014, 02:56:03 PM »
I wonder if it would be helpful to have a quasi-bayeresque multi-layer sensor.

So instead of having every pixel being constructed with what I assume would be a B/G/R construction, they decide to have some interspersed pixels with other channel arrangements. (e.g. R/G/B)

Personally, I like Panasonic's color splitting technique. It still preserves all of the light, but it has W-R and W+R pixels (white plus/minus red, which ends up being "bluish" and "reddish" pixels in the end). It doesn't filter at all, it just splits the light coming in and directs some component of it (red) to different pixels. It's supposedly 100% transmission (probably not exactly, 99.something%), and 2-3 times the sensitivity of bayer sensors (which should mean it's far more sensitive than a layered sensor, with high dynamic range and color fidelity:

http://image-sensors-world.blogspot.com/2013/02/panasonic-develops-micro-color-splitters.html

Di and Trichroic filters have been used before, most notably in "3 CCD camcorders".

57
EOS Bodies / Re: Multilayer Sensors are Coming From Canon [CR2]
« on: October 08, 2014, 11:21:22 PM »
Guys, is it possible to get 16-bit images with FF DSLRs in theory? Would it give any real life benefit vs. 14-bit?

Yes, and possibly.

58
EOS Bodies / Re: Multilayer Sensors are Coming From Canon [CR2]
« on: October 08, 2014, 10:48:16 PM »
Can someone explain to me why they're working on this rather than more megapixels?  Rather, why the focus is on more layers?  I understand it's to better represent colors.  But what is wrong with colors?  My cameras have always nice, realistic, vivid colors as long as I use a good lens.  I've never had a photograph where I even had the slightest hint of a thought that the color is not accurate.  When I look at my pictures, it looks like when I was there.  Granted, the dynamic range is not the same, but we're not taking pictures with our eyes, so that's expected.  What is it about color that they need to squeeze that last 0.01% of color accuracy out of the camera?

The problem with Bayer cameras isn't color, it's that the Bayer dyes absorb something like half the light coming in.  In theory, if you could go without that dye layer, you could gain a stop, or perhaps a bit more, of high ISO performance.

59
EOS Bodies / Re: Multilayer Sensors are Coming From Canon [CR2]
« on: October 08, 2014, 09:20:39 PM »
A problem with Foveon sensors is lousy color separation.  It's not a red, blue and green layer, it's three white layers with a little bit of bias on each one.  This is why they have lousy, inaccurate colors with lots of color artifacts like purple and green splotches all over the place.

I hope Canon has a way to dramatically improve on Foveon sensors before they'd release this into the wild.  Foveon's have lousy DR, lousy high ISO performance, lousy colors, and the lack of an AA filter means a ton of aliasing artifacts.

Hmm, that hasn't been my experience with Foveon images. They seem to have pretty good color fidelity at low ISO. They also seem to handle blues quite well, which isn't surprising given that blue is the top layer.

I was never impressed with the high ISO capabilities, and I think their higher ISO noise is pretty splotchy...but Canon noise is often just as bad (only Canon color splotches tend to be primarily reddish, with a bit of green.)

I'm talking about different splotches.  They aren't a few pixels like chroma noise, they're a few thousand pixels.

60
EOS Bodies / Re: Multilayer Sensors are Coming From Canon [CR2]
« on: October 08, 2014, 08:57:31 PM »
A problem with Foveon sensors is lousy color separation.  It's not a red, blue and green layer, it's three white layers with a little bit of bias on each one.  This is why they have lousy, inaccurate colors with lots of color artifacts like purple and green splotches all over the place.

I hope Canon has a way to dramatically improve on Foveon sensors before they'd release this into the wild.  Foveon's have lousy DR, lousy high ISO performance, lousy colors, and the lack of an AA filter means a ton of aliasing artifacts.

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