December 18, 2014, 02:50:41 PM

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Messages - Lee Jay

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196
The 400 5.6 prime beats them all, canon 100-400, sigma zooms, whatever.

A midrange zoom isn't supposed to "beat" a prime because unless you're focal length limited. With the zoom you can get the optimal sensor coverage meaning less noise and more sharpness because of less nr. With a prime, what do you do if your subject decides to get near you? Quickly switch to the 300L, 200L and 100L?

Walk backwards?

I don't own any primes yet, so that's just my working theory as of the moment.  As soon as I own some primes I can properly answer your question and back it up with the scientific method.  ;)

How fast can you walk backwards?  Most of my subjects approach at 100-200mph.

197
Time has passed this lens by - it is two years to late.
The 150-600 zoom is the new kid on the block and the imminent Sigma S version could be a very good lens.

It's nine years too late, and it will still be worth probably twice what the Tamron and Sigma C cost.  As for the Sigma S, it's too big and too heavy to hand hold 10 hours a day, which is what I will do with this lens.

198
The Tamron is $1,069.  This lens is 2/3 as long.  So, it will be $712.66.  CR2.

You're welcome.

199
EOS Bodies - For Stills / Re: How to differentiate crop vs. FF
« on: October 24, 2014, 09:10:58 AM »
You can use software (noise reduction and downsampling) to trade all that extra resolution for much lower noise in the overall image with the same sharpness (resolution), and in fact that's what you end up doing when you compare the two images at the same final size.
That's something else again. This discussion was related to the discussion regarding the intensity and total quantity of light and whether how that was affected (if at all) by the size of the sensor [before post processing].

Yeah...and you can't do what I said unless you have all that extra light captured in all those extra pixels.

Quote
All those photons that are collected by all those extra pixels count in the total signal (sharpness) to noise (noise) of the final overall image, and that's the reason that a larger sensor out-performs a smaller sensor in low-light despite having the same sized pixels.
No, those extra pixels don't count (again, before post processing).


Yes, they do.

One assumption that we always make is that quantization noise is negligible.  That means, you can't see the individual pixels.  If you can, that's another whole problem.

Since you can't see the individual pixels, your eye is essentially averaging some small number of pixels together.  The averaging works like this - the noise goes down with the square root of the number of pixels averaged.  Average 4 pixels, you cut the noise in half.  Average 9, you cut the noise by a factor of three.

This works out the same as the decrease in shot noise from all that extra light - SnR goes with the square root of the number of photons collected.

In reality, all larger pixels do is block average.  It turns out that block averaging is about the worst performing method of noise reduction there is.  Even the most basic noise reduction is better, and modern advanced method are enormously better.  So, smaller pixels that are block averaging less combined with modern noise reduction software will out-perform larger pixels since the larger pixel are doing the dumbest kind of noise reduction there is.

200
EOS Bodies - For Stills / Re: How to differentiate crop vs. FF
« on: October 24, 2014, 07:50:51 AM »
To get that crop reach advantage, you need a GREAT lens. A lens like the 100-400 or the Tamron 150-600 is not sharp enough.

Not true.

I'll challenge anyone to go out with a 1DX or 5DII or III and get a moon shot like this one with a 100-400L.



Hand held.

http://www.canonrumors.com/forum/index.php?topic=435.msg120132#msg120132
And here,
http://photography-on-the.net/forum/showthread.php?p=10014826

As I said...not even close.

Oh, I missed the bit where you didn't mention the TC, that was naughty of you. There are loads more FF images out there with 5D MkII/III's with TC's that are every bit as good as yours, I was just looking for 100-400's.

Why?  That shows that the bare lens was sharp enough to be dramatically out resolving the sensor, which itself had pixels 1.6x smaller than those in the 1DX.  Oh, and this was a 2x TC and this shot was slightly better than the same shot taken with just a 1.4x.  That's like a 72MP 1.6 crop sensor or a 184MP full frame sensor.  And that's on a 16 year old zoom lens.

201
EOS Bodies - For Stills / Re: How to differentiate crop vs. FF
« on: October 23, 2014, 11:39:27 PM »
To get that crop reach advantage, you need a GREAT lens. A lens like the 100-400 or the Tamron 150-600 is not sharp enough.

Not true.

I'll challenge anyone to go out with a 1DX or 5DII or III and get a moon shot like this one with a 100-400L.

Nice image, well processed; but not sure I see the point.

It was shot with a 100-400L + 1.4x TC - so you could not even capture that image on a crop camera with the 100-400L alone.

Phil.

And what's the purpose of a TC?  Answer:  To compensate for the sensor under sampling the lens.  A 1.4x TC can be thought of as shrinking the pixels by 1.4x or as doubling the pixel count, rather than doing anything optically.  They are equivalent, and in both cases if the lens isn't resolving the detail, the extra pixels or extra magnification won't help.  But it does help as you just said yourself.  And you are right.

202
EOS Bodies - For Stills / Re: How to differentiate crop vs. FF
« on: October 23, 2014, 11:35:49 PM »
To get that crop reach advantage, you need a GREAT lens. A lens like the 100-400 or the Tamron 150-600 is not sharp enough.

Not true.

I'll challenge anyone to go out with a 1DX or 5DII or III and get a moon shot like this one with a 100-400L.



Hand held.

http://www.canonrumors.com/forum/index.php?topic=435.msg120132#msg120132
And here,
http://photography-on-the.net/forum/showthread.php?p=10014826

As I said...not even close.

203
EOS Bodies - For Stills / Re: How to differentiate crop vs. FF
« on: October 23, 2014, 11:11:28 PM »

SNR = sqrt(photon count)

True, but I believe that's photon count per pixel. I'm trying to understand how the the total photon count on the sensor matters.

If you only look at one pixel, the per-pixel photon count would be all that matters.  If you look at a whole image, the whole image photon count is what matters.

I don't think so. You've probably seen this before
http://theory.uchicago.edu/~ejm/pix/20d/tests/noise/

For the shot noise, its only a function of the number of photons captured by a pixel.

The shot noise for that pixel.

Quote
Its the physics of why the crop (smaller pixels) shot noise can never be as low as the FF.

Shot noise is also called "photon counting noise".

If you have a larger sensor with the same pixel count, the shot noise per pixel is lower.

If you have a larger sensor with the same sized pixels, the shot noise for each pixel is the same, but you have many more pixels.

You can use software (noise reduction and downsampling) to trade all that extra resolution for much lower noise in the overall image with the same sharpness (resolution), and in fact that's what you end up doing when you compare the two images at the same final size.

All those photons that are collected by all those extra pixels count in the total signal (sharpness) to noise (noise) of the final overall image, and that's the reason that a larger sensor out-performs a smaller sensor in low-light despite having the same sized pixels.  It's also why cropping 1.4x (linear) is like increasing ISO by 1 stop, and cropping 2x (linear) is like increasing ISO by 2 stops (as far as noise is concerned) - the same as a teleconverter requires for the same shutter speed.

204
EOS Bodies - For Stills / Re: How to differentiate crop vs. FF
« on: October 23, 2014, 10:12:03 PM »
To get that crop reach advantage, you need a GREAT lens. A lens like the 100-400 or the Tamron 150-600 is not sharp enough.

Not true.

I'll challenge anyone to go out with a 1DX or 5DII or III and get a moon shot like this one with a 100-400L.


205
EOS Bodies - For Stills / Re: How to differentiate crop vs. FF
« on: October 23, 2014, 09:37:20 PM »

SNR = sqrt(photon count)

True, but I believe that's photon count per pixel. I'm trying to understand how the the total photon count on the sensor matters.

If you only look at one pixel, the per-pixel photon count would be all that matters.  If you look at a whole image, the whole image photon count is what matters.

206
EOS Bodies - For Stills / Re: How to differentiate crop vs. FF
« on: October 23, 2014, 09:12:30 PM »
In the real world, with the cameras Canon makes now, FF wins the IQ contest in all but one scenario... and that scenario is when you are focal length limited, can't move any closer, have a GREAT lens, and good lighting. Under those conditions (happens a lot with small birds) the quality of your crop pixels is fairly close to your FF pixels, but you have more crop pixels on target so you end up with a better image from the crop camera.  Everywhere else, FF wins.

No, there's another one - when you're magnification (as in macro) limited.

207
EOS Bodies / Re: 4K Products Coming From Canon [CR2]
« on: October 23, 2014, 08:22:17 PM »
Who would be okay with Canon implementing 4k on the lower end products (7D2, 5D4, C100, high end compacts, etc.) through a 1:1 pixel implementation?  That would give the 7D2 an additional 1.425x crop on top of the 1.6, for example.  It would require a lot less processing power and software.

Personally, I'd be okay with that.

208
EOS Bodies - For Stills / Re: How to differentiate crop vs. FF
« on: October 23, 2014, 07:48:49 PM »

True, but the 2.56x greater area of the FF sensor will gather more total light.  Comparing noise at the pixel level isn't the same as comparing noise at the image level.

There's shot noise, which is clearly related to the size of the pixel and I thought that the signal processing to convert the analog to digital was done on a pixel-by-pixel basis, which would make the read noise related to the pixel photon count, too.  Is that so? If so, what else would make the image level noise different? In other words, how does the total amount of light collected by the sensor come into the noise calculation?

SNR = sqrt(photon count)

209
EOS Bodies / Re: Canon Announces the Cinema EOS C100 Mark II
« on: October 23, 2014, 10:48:12 AM »
SHARING - WIFi, wireless iOS and Andriod inegration with cameras, file transferst etc, THEY NEED IT NOW

FASHIONABLE PRODUCTS - COLOR COLOR COLOR, they turned out a great white SLR, but ARE NOT SELLING IT RIGHT!!! You sell it as a Dolce Gabbana camera and shoot the spring campaign on it, and then make fabulous bags and sell it in fashion retail stores. It's not hard! General population doesn't care to go to B&H to see a white camera, it needs to be where the fashion is!

These are what are important to you?  That's pretty sad.

210
EOS Bodies / Re: Canon Announces the Cinema EOS C100 Mark II
« on: October 23, 2014, 10:28:51 AM »
I also see no reason to record 4K today.

So I can stabilize in post, crop, downsample, and still have 1080p left.

This is a legitimate response, but this camera is aimed at people using professional-style rigs, no? So stabilisation isn't really an issue.

For fast objects, it always is, even with a fluid head, optical IS, and electronic stabilization.

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