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Messages - Lee Jay

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1
Lenses / Re: New Lens Information for Photokina
« on: August 29, 2014, 05:24:03 PM »
No you didn't, the request was for comparisons between a 7D/70D and a 5D MkII/5D MkIII/1Ds MkIII/6D/1DX handheld with AF.

I don't care about your request (which changes every time), I care about a controlled test demonstrating the point.  And I provided that.

Well you did care enough to argue the point, and you failed.

My request hasn't changed, I just broadened it to include more cameras to make it easier. Here is the original request:

Quote
Show me one test done with the same lenses from the same place shooting the same subject handheld whilst using AF that demonstrates the 7D's resolution advantage.

If by showing tripod mounted shots from a 20D and a 5D you think you have demonstrated the 7D's resolution advantage when hand held you have a different understanding of Engish than I do, or, to quote you, "Idiot".

I demonstrated it with a controlled test, not an uncontrolled one.  It's not my fault you don't have the skills to extract full resolution from your systems in real-world shooting.

2
EOS Bodies / Re: EOS 7D Mark II & Photokina
« on: August 29, 2014, 05:19:55 PM »
If you just check how 300 2.8 mk2 IS perform on 1ds iii in DXO showing 21mp of 21mp resolving power.
Witch means almost perfect lens for this size/mp sensor.
Same lens on Canon 70d produce 17mp from 20mp. This means 3mp is throw away due to smaller sensor. And this is in perfect test conditions. On the field you will throw out  even more 10mp for sure.

And, at the same range, the 21MP will be reduced by a factor of 1.6^2 (2.56), leaving 8.2MP.

In other words, the larger sensor only has an advantage if you can use a larger lens or wait until the subject is closer.  At the same range, it has a disadvantage because of its large pixels.

3
Lenses / Re: New Lens Information for Photokina
« on: August 29, 2014, 04:46:13 PM »
No you didn't, the request was for comparisons between a 7D/70D and a 5D MkII/5D MkIII/1Ds MkIII/6D/1DX handheld with AF.

I don't care about your request (which changes every time), I care about a controlled test demonstrating the point.  And I provided that.

4
EOS Bodies / Re: EOS 7D Mark II & Photokina
« on: August 29, 2014, 04:43:04 PM »
So moving to a smaller process to shrink the borders does not affect the amount of light captured for each pixel because of the gapless microlenses?

Pretty much, yes.

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If microlens size = photo site + border, then it would seem that a larger pixel-with-microlens would gather more light than a smaller pixel-with-microlens. Are you saying that the resolution (given the same sensor dimensions) is higher for the smaller pixels so when you compress the image to the same resolution as the sensor with the larger (fewer) pixels, the overall light/data collected for the multiple smaller pixels, now sized-down to the lower resolution end up producing essentially the same image quality?

Yes, though if you do the down-sizing properly, the smaller pixels will generally win, and quite easily.

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Am I understanding this right? Does this mean that if I want to enjoy the same image quality as the sensor with fewer pixels I have to compress the resolution of my images to match?

That depends on what you mean by image quality.  Resolution?  Noise?  With the smaller pixels, you have the option to reduce noise at the expense of resolution.  On the larger pixels, that part has been done for you and you have no choice.

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One other thought: microlenses perfectly focusing the light on the photo site sounds great on paper. How precisely do the lenses do this in the real world? If they're nearly perfect, how in the world do they accomplish such precision on such a small scale? Simply amazing to me...

The efficiency varies with the design, but it's quite close to all of the light.  They do this using the techniques of photolithography, which is quite a precise thing, especially in the more modern versions.

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If the microlenses do their job, then I guess it's not light/surface-area that makes the difference between crop and full frame. Could it be that for the smaller pixels, there's more opportunity for noise to be introduced by the supporting circuitry? Something must be happening, because it seems that sensors with larger pixels seem to do better for noise at high ISO.

They do this because they use more sensor area, not because they use larger pixels.  When you have the same f-stop, the light intensity (called "illuminance" - light per unit of area) is the same (for a given scene), and that means a sensor with more area captures more light.  Since signal-to-noise ratio goes with sqrt(total light captured), more area (bigger sensor) means better signal to noise ratio for the same f-stop.  That's why larger sensor perform better in low light.

Another way to look at the same thing is to express f-stop as its definition - focal length / aperture.  So, a lens with a 100mm focal length and a 25mm aperture has an f-stop of 4 (it's often written as its reciprocal - 1/4 or 1:4).

Well, let's say you want to use your 100/4 on your full-frame camera.  To what do you compare?  Well, on a 1.6-crop camera, you might use the same lens zoomed out to 62.5mm so that you have the same angle of view.  62.5mm / 4 = 15.625mm compared with 25mm on the full-frame camera.  That's a lot smaller hole for the light to squeeze through, and so you get a lot less.

The two explanations are equivalent.

5
Lenses / Re: New Lens Information for Photokina
« on: August 29, 2014, 04:16:37 PM »
Well do you have proof of that or is it just another guess like your ff comparison without actually using a ff?

You say a lot of dumb things.  I have over 50,000 shots on my 5D, which I purchased at release.

I have talked with owners that love their 400/4DO.  Not so much the 70-300.

And you are my equal.

For all your 10,000's of shots you still couldn't post two images to illustrate your belief and assertions.

Yes, I did.  Since you're memory seems to be failing you, here it is:



And, if you prefer to see them at native (but different) sizes, here's that one too:

6
EOS Bodies / Re: EOS 7D Mark II & Photokina
« on: August 29, 2014, 04:14:20 PM »
So the 6 MP p&s S3IS has better IQ of the 13 MP full frame 5D?

No, the 2.04 micron pixels of the S3IS provide better IQ behind the same lens as the 8.2 micron pixels of the 5D.  In other words, small pixels win.

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Could you provide a link please so that I can see all by myself without asking you more detail? Thanks.

I don't know what link you want.  They're my pictures.

The reason this works is pretty simple - the same amount of light falls on the same area of the sensor regardless of how you divide that sensor up into pixels.  Lots of small ones or one large one, it's all the same light.  The difference is, with the small ones, you can choose to reduced your resolution down to the same as you get from the large one (and reduce noise along with it), or not.  You can't make that choice with the larger pixels.  Further, when you reduce your resolution, you can choose to use far more effective techniques than the simple block-averaging approach that is effectively what the larger pixels are doing - averaging over the large block size of the large pixels.

7
Lenses / Re: New Lens Information for Photokina
« on: August 29, 2014, 03:43:01 PM »
Well do you have proof of that or is it just another guess like your ff comparison without actually using a ff?

You say a lot of dumb things.  I have over 50,000 shots on my 5D, which I purchased at release.

I have talked with owners that love their 400/4DO.  Not so much the 70-300.

8
EOS Bodies / Re: EOS 7D Mark II & Photokina
« on: August 29, 2014, 03:39:23 PM »
Too many of you claim that a higher MP sensor does not have more noise than a lower MP one, all conditions being equal, and support this claim with mathematics, but that's not true in the real world. Some even claim that smaller photosites have less noise than bigger ones: now, that's the kind of claim that should make all of us invoke Santa, bigfoot and rainbow-pooping unicorns going on vacation together with a flying saucer. The real world behaves differently.

Oh, really.  Same ISO, same f-stop, same shutter speed, same focal length, same subject, same lighting, shot in raw, same raw processing tool.  The pixels on the left are 1/16th as big (in area) as the pixels on the right.



Which ISO? Which f-stop? Which sensors? Could you provide a link, please? I've found this

ISO 800 (the highest setting available at the time on the small pixels.  The cameras as the Canon S3IS and the Canon 5D.

9
Lenses / Re: New Lens Information for Photokina
« on: August 29, 2014, 03:23:28 PM »
I don't, but I have put up with Canon's loss leading tech pet projects for a long long time, and DO is one.

It is a fair assumption that it isn't ready for prime time because of what it is and why it does wrong what it does wrong. With current tech the only way to negate the impact of putting steps into a perfectly smooth surface is to counteract it in software.

Now if Canon have invented a different way to bend light at the very least I would expect them to call it a new technology, for goodness sake they can paint a Rebel red and call it new, something like Diffractive And Micro Nano Glass Observational Optical Detail. We live in hope.

Diffractive optical elements do bend light, and they do it using a different approach than refraction.  This comes with a couple of major advantages compared with conventional refractive elements.  For one, the refractive index of the glass isn't the limitation on how much the light can be bent.  Secondly, the DO elements produce CA in the opposite direction as conventional elements thus making it greatly easier to correct CA with down-stream elements.  Both of these lead to smaller lenses that do the same job as conventional refractive lenses.

Here, read up:

http://www.usa.canon.com/cusa/consumer/standard_display/Lens_Advantage_Perf#f

I know and understand exactly how DO works, my point was they need to have come up with yet another way of bending light (hence the use of those words) to get over the intrinsic issues the DO introduces, despite the advantages, the disadvantages have proven to make the idea incompatible with consistent high quality photographic output.

I used two DO lenses for a day and instantly realised they were not good.

And yet, many owners just love them.

10
EOS Bodies / Re: EOS 7D Mark II & Photokina
« on: August 29, 2014, 03:15:48 PM »
Too many of you claim that a higher MP sensor does not have more noise than a lower MP one, all conditions being equal, and support this claim with mathematics, but that's not true in the real world. Some even claim that smaller photosites have less noise than bigger ones: now, that's the kind of claim that should make all of us invoke Santa, bigfoot and rainbow-pooping unicorns going on vacation together with a flying saucer. The real world behaves differently.

Oh, really.  Same ISO, same f-stop, same shutter speed, same focal length, same subject, same lighting, shot in raw, same raw processing tool.  The pixels on the left are 1/16th as big (in area) as the pixels on the right.


11
EOS Bodies / Re: EOS 7D Mark II & Photokina
« on: August 29, 2014, 02:50:54 PM »
Dare I wade into the pizza war?  :P

Perhaps I can translate it into a wooden pizza to fit one of my other hobbies: If I have a 15" maple disc, cutting it into 6 pieces WOULD give me more maple surface area than cutting it into 8 pieces. Why? because there is waste from blade kerf. If I have a 1/8" kerf, I lose an approximately 1/8" slice of material with each cut. Let's say now that we fill in each cut with a 1/8" slice of ebony so we don't lose overall surface area when we glue it all up. The disc maintains its original surface area, but there is still less maple surface area with 8 slices than with 6. Using a 1/16" kerf blade will increase the ratio of maple surface area to ebony, but there will still be less maple surface area with 8 slices than with 6.

Now imagine the disc is actually a rectangle, and the pieces are squares instead of pizza slices. The maple is the photo-sensitive portion of the sensor, and the ebony is the border around each pixel. If sensor size and transistor size are constant, doesn't increasing the number of pixels increase the number of borders and transistors, and doesn't that reduce the portion of the overall sensor that receives light? Is moving from a 500nm process to a 180nm process like going from a 1/8" kerf to 9/200" kerf?

I'm obviously not a sensor geek, so I might be completely misunderstanding pixels, borders, et cetera. What am I missing in this analogy?  :P

What you're missing is gapless microlenses, which essentially render the "blade kerf" largely moot by concentrating the light into the light-sensitive area between the "kerf lines".

12
Lenses / Re: New Lens Information for Photokina
« on: August 29, 2014, 02:48:42 PM »
I don't, but I have put up with Canon's loss leading tech pet projects for a long long time, and DO is one.

It is a fair assumption that it isn't ready for prime time because of what it is and why it does wrong what it does wrong. With current tech the only way to negate the impact of putting steps into a perfectly smooth surface is to counteract it in software.

Now if Canon have invented a different way to bend light at the very least I would expect them to call it a new technology, for goodness sake they can paint a Rebel red and call it new, something like Diffractive And Micro Nano Glass Observational Optical Detail. We live in hope.

Diffractive optical elements do bend light, and they do it using a different approach than refraction.  This comes with a couple of major advantages compared with conventional refractive elements.  For one, the refractive index of the glass isn't the limitation on how much the light can be bent.  Secondly, the DO elements produce CA in the opposite direction as conventional elements thus making it greatly easier to correct CA with down-stream elements.  Both of these lead to smaller lenses that do the same job as conventional refractive lenses.

Here, read up:

http://www.usa.canon.com/cusa/consumer/standard_display/Lens_Advantage_Perf#f

13
EOS Bodies / Re: EOS 7D Mark II & Photokina
« on: August 29, 2014, 11:40:14 AM »
A 12mp sensor would have better high ISO performance,

No, it wouldn't.  This myth just won't go away.

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utilize the center of lens elements,

Which is wrong on two levels - every pixel uses all of the lens elements.  You may have meant "image circle" instead of lens elements.  Secondly, using the "sweet spot" is nearly always detrimental compared to using the entire image circle because of increased enlargement.

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And also, a 12 mp crop sensor is 150% of the "reach" and 16mp is 200% of the "reach"... As you put it.

"Reach" means "resolving power" and it goes with the square of pixel count.  You want to double resolving power?  You need four times as many pixels.

Whatever... my opinions are derived from "field" observation... and interestingly I have found that most things being equal, larger pixels translate to higher ISO noise usability.... and that the center of images are always sharper and have less distortion than the edges.  But who needs field observations when we have all of these "theoretical" photographers here on the forum to prove us all wrong??

I've got a quarter million shots under management in LR.  I wouldn't call that theoretical.

You're noise observation is wrong because you are comparing at different enlargement ratios (1:1 with all pixel counts).

Your center image circle is wrong because you aren't comparing crops and full image circle images at constant final size.

And what I said about "reach" (resolving power) is correct.

14
Lenses / Re: New Lens Information for Photokina
« on: August 29, 2014, 10:40:29 AM »
I'm not sure either, unless they sell this for $300-400 or something.  Perhaps they see it as a 28-135 IS replacement more than a 24-105 replacement.

Bingo.

15
Lenses / Re: New Lens Information for Photokina
« on: August 29, 2014, 10:30:09 AM »
Who the heck would want a FF lens that only goes to f/5.6 at 105mm? 
Not me, but people that want a light, cheap lens for landscape, travel, & studio use where shallow DOF is never used.  6D shooters would likely be the target for this lens.

Your logic makes about as much sense as saying who would want a crop sensor, or would want a camera any less tough than the 1D X.

There's this little thing called market segmentation.  It's how big companies make money.  Reference Canon's profits on the Rebel line vs. the 1D line.

I think the logic is ok.  You are talking about what people will accept, not what they want.

I'm thinking about how dSLR's continue losing ground, and that putting out mediocre lenses which will produce disappointing results for new buyers accelerates that.

I'm committed to Canon.  I'm satisfied with my gear, in some cases extremely pleased.  I'd recommend Canon.  Their CPS is fantastic.

But I do think it is ok to point out blunders and express disappointment.

Just because a lens is slow does NOT mean that's it's optically lousy.

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