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Messages - ecka

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61
Lenses / Re: Is there a need for a 50mm?
« on: September 07, 2014, 04:14:51 PM »
I love walking around with my 70-200 with the 40 in my pocket.
You really need big pockets to put in the 70-200 should you want to switch to the 40, though.

That's doable, actually. All you need is a strap for your 70-200, instead of the body. :)

62
Lenses / Re: Is there a need for a 50mm?
« on: September 07, 2014, 04:11:56 PM »
I'd just be interested in knowing of a fast zoom that's faster than f/2.8 regardless of the make/compatibility.  I've never seen one to my knowledge.

Sigma 18-35mm f/1.8...generally considered an excellent lens.  It's for APS-C only, though.

Yeap, no need for fast primes on crop since 18-35/1.8 arrived, unless you have some kind of pocketability fetish ;).

64
EOS Bodies - For Stills / Re: Guessing Game- Canon or Nikon?
« on: September 04, 2014, 05:37:28 PM »
Sorry but this thread would only make sense if one were posting unedited RAW files taken under controlled conditions. Once processing is allowed we are looking at the skill of the person processing the image not just the capabilities of of the camera + lens.
I really don't understand the constant Canon vs Nikon squabbles - for my uses Canon is better but for many others Nikon is a better choice.
So the best advice is choose - don't waste time on endless and pointless discussions which resolve nothing and inform nobody.

Interesting. That is the entire point of this thread. You are a quick study. :-)

The camera brand is irrelevant. Many people here on cr argue vehemently for one brand over another... Trying to convince each other through theory, physics and math. Bottom line... None of it really matters. Whether a camer has 10 stops of DR or 11 or 12... Doesn't matter!

Also, to further my point... No one shares raw files. They are not finished products. It's the capture and the post processing of these files that makes an image. The intent of this thread is not to actually compare sensors or brands... It's to point out that while those details can make a difference to some... In the big picture it really just doesn't matter. Even the people who an extra stop or two of DR makes a HUGE difference, it is only in a tiny percentage of the images they make.

I applaud the point you are trying to make.

I've never gotten the Nikon vs. Canon thing myself. Just as I've never gotten the APS-C vs. Full Frame fight.

I've tried to make the point many, many times that the most inexpensive DSLR today is light years ahead of what could be produced during the film era.

But, the reality is: 1) people need to justify their purchases, so they "see" differences that either don't exist or don't matter; 2) some people have a deep seated need to have the "best" and they take offense when they perceive that someone else might own a product that is "better" even though it may be in some small, insignificant way; 3) Some people just like to be argumentative and get their jollies by making outrageous statements and watching people react; 4) Some people are unable to reconcile the reality that they may not be the greatest photographer who ever walked the earth and think that if they just had the other guy's camera they would be a better photographer; 5) Some people just need to be on a "team" and root for their side.

Camera brand matters mostly before shooting and while editing the image, not after all the work is done.

I think you miss the point. Camera brand doesn't matter.

Sure it does. After all this is CanonRumors, not WhateverCameraRumors :).

65
EOS Bodies - For Stills / Re: Guessing Game- Canon or Nikon?
« on: September 04, 2014, 03:31:03 PM »
Camera brand matters mostly before shooting and while editing the image, not after all the work is done.

66
Here is a way of calculating the effective extra reach or resolving power of a crop body versus FF, which will amuse the geeks among us...

MTF is not a measure of resolution, it is a measure of a lenses ability to transmit contrast of the original scene through a lens.  That's all it measures.

If what you really want is true image resolution, then there are two correct ways of measuring it.  The first is a measurement of the performance of the lens itself.  This measurement can be found in using something like a USAF resolution test chart and a microscope to perform aerial inspections of the image of the chart after it has passed through the lens.

Problems with this approach include difficultly in setting up a test bench (it's not easy at all).  Additionally, the final result will not include measurements of chromatic aberrations, image distortions, field curvature, etc.  The most important missing element in this kind of test is the exclusion of the imaging system itself.  However, if the question is about real optical resolution, this test will give you the right answer.

Which leads to the second way of measuring, well, actually calculating real image resolution.  This is diagnostic and very simple to perform.  Simply take the number of image points ("pixels") in your file, divide by the size of your sensor (in millimeters), and divide by two.  This number will represent the number of Line Pair per Millimeter (the measure of the ability to go from one white line to one black line) that your sensor can resolve.

This is rather interesting in that you can quickly see that a Canon 7D 18 mpixel sensor is capable of resolving 116 line pair per mm.  The Canon 5D MkII is capable of 78 lppmm.  As a comparison, Sony's 36mpixel FF sensor is capable of resolving 102 lppmm and Phase One's monster 80mpixel IQ180 returns 97lppmm.

Taking this a step further, look carefully at the physical limits (as in optical physics) of optical resolution, as measured in lppmm.  You see that at f/2, an optically correct lens will return 695lppmm in the center of the scene where the light's wavelength is 589.3mu (green).  At f/11, an optically correct lens will return 123lppmm, dropping off to 92lppmm at 25 degrees off-axis tangential.

Looking at this over the years, I have come to realize there is seldom a lens in-capable of resolving so poorly that a sensor (or old film for that matter) could out-resolve the lens.  Sure, there are other optical effects, but we are talking pure resolution here.  Nothing more.

Think about this for a moment.  MTF does _not_ measure optical resolution.  While useful, it does _not_ tell the story of resolution, no matter how much "math" you throw at it.  Secondly, and perhaps most interestingly, optical physics show diffraction limited resolution at f/11 EXCEEDS currently manufactured sensors ability to return that resolution in all cases. 

Rather shocking, don't you think?

Back to the original poster's point: Canon's 7D sensor outresolves (using the correct application of the word "resolution") the FF sensors from any manufacturer.  It does so, however, for reasons other than those that were brought up.

Correct application of rational thought and real world science can help us properly understand and identify the errors and misleading comments widely published by marketeers and critics of optical imaging systems.

You see, if Canon had made a FF camera with 7D's pixel density, then there wouldn't be any questions - FF wins, period.
Nikon did that with their D7000/D7100 vs D800/D810. You crop FF and you get almost exactly what the pre-cropped D7000/D7100 produce. In fact, you can just shoot in DX mode on D800...
So there is no global question about crop winning anything vs FF other than price.
The question is why Canon didn't make that 46mp FF camera?
Was it because consumers didn't ask for it? - Maybe.
Why didn't they ask for it? - Because they are too ignorant in How-It-Works department. They are affected by this ... More_Pixels=More_noise=Bigger_Files=My_Old_iBox_Can't_Handle_it
=Crop_Is_Just_As_Good_It's_Just_Magically_Different_Because_Size_Doesn't_Matter
=I_Better_Buy_An_Overkill_Lens_For_My_Crop_And_Not_Use_The_Rest_60%_Of_It
=I_Don't_Need_That_Much_Pixels_But_Digital_Zoom_Is_Bad#!@ERROR*2&$ERROR...
System_Reset~Hello_Micro_Four_Thirds=Must_Buy_35-100/2.8_Because_It_Is_70-200/2.8
 ... virus :).

Lmao, +1

You forgot the part about how the equipment doesn't matter, and a good photographer could take a photo better than the hubble deep field with their iPhone.

Thanks for reminding about that one. Actually, there are plenty of them (like - "macro lenses are too sharp for portraits" or "I shoot JPEG, because I'm no pixel-peeper" or "look at these 300x200 images, 1DX and a Rebel both look the same, so why pay more..."), but who's counting :)

67
You see, if Canon had made a FF camera with 7D's pixel density, then there wouldn't be any questions - FF wins, period.
Nikon did that with their D7000/D7100 vs D800/D810. You crop FF and you get almost exactly what the pre-cropped D7000/D7100 produce. In fact, you can just shoot in DX mode on D800...
So there is no global question about crop winning anything vs FF other than price.
The question is why Canon didn't make that 46mp FF camera?
Was it because consumers didn't ask for it? - Maybe.
Why didn't they ask for it? - Because they are too ignorant in How-It-Works department. They are affected by this ... More_Pixels=More_noise=Bigger_Files=My_Old_iBox_Can't_Handle_it=Crop_Is_Just_As_Good_It's_Just_Magically_Different_Because_Size_Doesn't_Matter=I_Better_Buy_An_Overkill_Lens_For_My_Crop_And_Not_Use_The_Rest_60%_Of_It=I_Don't_Need_That_Much_Pixels_But_Digital_Zoom_Is_Bad#!@ERROR*2&$ERROR...System_Reset~Hello_Micro_Four_Thirds=Must_Buy_35-100/2.8_Because_It_Is_70-200/2.8 ... virus :).

I think it's more than that, really.

Think about this from the manufacturer's point of view.  The electronics you use to integrate your system cost real money.  The Bill Of Materials (BOM) will add up quickly as you select higher performing parts.  Over time, the cost of parts will drop (typically) as newer, faster parts become available.

So it's a balance of price and performance.

From a business perspective, how much Gross Margin do you think you can recover?  Answer that with the number of units sold and you'll be well on your way to finding out what the company's quarterly profit will be.

From an electronics point of view, proprietary data-busses (how data moves around inside your camera) are not cheap.  Even when you build a system based on existing, open specifications, you still have to source the parts and make sure they will be available over the life of your product (not easy in this day and age).  The more mega-pixels you design into your system, the faster your busses need to be to keep the beast from being Dog Slow.

I'm not saying it's not possible.  Obviously, if Sony can say they'll release a 50mpixel FF sensor in a couple years, Canon could certainly do it too.  But I think the companies are waiting for the BOM costs to drop, mixed with the corporate Gross Margin targets, into the region people will be willing to pay for a new toy.

Isn't 5D2 the most popular FF DSLR, which was an overpriced MEGApixel monster back in 2008 that forced everyone to buy larger capacity memory cards and new PCs; enjoy FullHD videos they didn't want and struggle shooting sports/action with it's inferior AF system and burst rate because they wanted those beautiful FF images?
All that whining about how much work has to be done and all the investments and new technologies ... is just unreasonable. We pay for it. We vote with our money for what we want. There may be 5D Mark 4 coming at Photokina and we can't stop it :) and I hope it will have 50+ mega pixels in it :) and 4K :) and maybe a hybrid viewfinder (OVF+EVF) :) and a 4" touch screen :) and quad-pixel AF or something :) and all that for only $3999 :).

68
Here is a way of calculating the effective extra reach or resolving power of a crop body versus FF, which will amuse the geeks among us...

MTF is not a measure of resolution, it is a measure of a lenses ability to transmit contrast of the original scene through a lens.  That's all it measures.

If what you really want is true image resolution, then there are two correct ways of measuring it.  The first is a measurement of the performance of the lens itself.  This measurement can be found in using something like a USAF resolution test chart and a microscope to perform aerial inspections of the image of the chart after it has passed through the lens.

Problems with this approach include difficultly in setting up a test bench (it's not easy at all).  Additionally, the final result will not include measurements of chromatic aberrations, image distortions, field curvature, etc.  The most important missing element in this kind of test is the exclusion of the imaging system itself.  However, if the question is about real optical resolution, this test will give you the right answer.

Which leads to the second way of measuring, well, actually calculating real image resolution.  This is diagnostic and very simple to perform.  Simply take the number of image points ("pixels") in your file, divide by the size of your sensor (in millimeters), and divide by two.  This number will represent the number of Line Pair per Millimeter (the measure of the ability to go from one white line to one black line) that your sensor can resolve.

This is rather interesting in that you can quickly see that a Canon 7D 18 mpixel sensor is capable of resolving 116 line pair per mm.  The Canon 5D MkII is capable of 78 lppmm.  As a comparison, Sony's 36mpixel FF sensor is capable of resolving 102 lppmm and Phase One's monster 80mpixel IQ180 returns 97lppmm.

Taking this a step further, look carefully at the physical limits (as in optical physics) of optical resolution, as measured in lppmm.  You see that at f/2, an optically correct lens will return 695lppmm in the center of the scene where the light's wavelength is 589.3mu (green).  At f/11, an optically correct lens will return 123lppmm, dropping off to 92lppmm at 25 degrees off-axis tangential.

Looking at this over the years, I have come to realize there is seldom a lens in-capable of resolving so poorly that a sensor (or old film for that matter) could out-resolve the lens.  Sure, there are other optical effects, but we are talking pure resolution here.  Nothing more.

Think about this for a moment.  MTF does _not_ measure optical resolution.  While useful, it does _not_ tell the story of resolution, no matter how much "math" you throw at it.  Secondly, and perhaps most interestingly, optical physics show diffraction limited resolution at f/11 EXCEEDS currently manufactured sensors ability to return that resolution in all cases. 

Rather shocking, don't you think?

Back to the original poster's point: Canon's 7D sensor outresolves (using the correct application of the word "resolution") the FF sensors from any manufacturer.  It does so, however, for reasons other than those that were brought up.

Correct application of rational thought and real world science can help us properly understand and identify the errors and misleading comments widely published by marketeers and critics of optical imaging systems.

You see, if Canon had made a FF camera with 7D's pixel density, then there wouldn't be any questions - FF wins, period.
Nikon did that with their D7000/D7100 vs D800/D810. You crop FF and you get almost exactly what the pre-cropped D7000/D7100 produce. In fact, you can just shoot in DX mode on D800...
So there is no global question about crop winning anything vs FF other than price.
The question is why Canon didn't make that 46mp FF camera?
Was it because consumers didn't ask for it? - Maybe.
Why didn't they ask for it? - Because they are too ignorant in How-It-Works department. They are affected by this ... More_Pixels=More_noise=Bigger_Files=My_Old_iBox_Can't_Handle_it=Crop_Is_Just_As_Good_It's_Just_Magically_Different_Because_Size_Doesn't_Matter=I_Better_Buy_An_Overkill_Lens_For_My_Crop_And_Not_Use_The_Rest_60%_Of_It=I_Don't_Need_That_Much_Pixels_But_Digital_Zoom_Is_Bad#!@ERROR*2&$ERROR...System_Reset~Hello_Micro_Four_Thirds=Must_Buy_35-100/2.8_Because_It_Is_70-200/2.8 ... virus :).

69
EOS Bodies / Re: Mirrorless vs DSLR Camera
« on: August 29, 2014, 09:09:37 AM »
I like both. Mirrorless has a big future. Once the AF gets up to speed and the EVF evolves sufficiently, what else has to happen? Based on the game-changing specs & performance & gob-smacked reviews of the mirrorless Panasonic GH-4 I bought one for my video work where it tidily beats the pants off my 5D3 in all situations with the exception of high iso shooting (over 1600 iso).

After using the GH-4 for a couple of months I'm discovering the sheer brilliance of it's very decent EVF and surprisingly good AF; much much quicker and accurate than I initially expected. Now that Adobe DNG converter v8.6 and Lightroom v5.6 can see the GH-4 RAW files, I've even been using it for stills on some commercial jobs.

Mirrorless is evolving fast. It's great to use. I'd hate to see favourite mainstream manufacturers (cough, cough..) being caught flat footed as this revolution gains pace.

-pw

GH4 is a brilliant tool for video. Have you tried the Sigma 18-35/1.8 via SpeedBooster on it? Some say it helps to overcome the high ISO disadvantage very effectively.

70
Lenses / Re: Help deciding on going full frame
« on: August 27, 2014, 01:40:33 PM »
With full frame costing less than $1,500 now (used or on sale), I can't think of any reason to stay on crop unless your budget is under $1,000.

Even if your budget is under $1000, a used 5D Classic goes for around $500 and is a much better option than pretty much any crop camera in that $500-1000 range in my opinion.

I'm not sure about the $500 5D, but no crop can beat 40/2.8STM on FF :).

71
Lenses / Re: A New Pancake Lens? [CR1]
« on: August 27, 2014, 12:47:07 PM »
I really am not concerned with how a camera looks, but the A7 just makes the 6D look like 1990's aesthetic.

Really? Isn't the A7 looking more retro?... from seventies :)

72
Lenses / Re: A New Pancake Lens? [CR1]
« on: August 27, 2014, 12:41:16 PM »
I'd like to see them also come out with a 30mm f2.8 Pancake. Great "near 50mm" equivalent for crop frames.  Would still expect it to be EF rather than EF-S--just have a slightly different utility on crop vs. full. :)

Yeap, nice 50/4.5 equivalent for crop frames :). There is really not much of size or price reduction in APS-C realm.

73
Third Party Manufacturers / Re: Samyang Teases New Lenses
« on: August 27, 2014, 12:02:45 PM »
There is no such thing as a "macro" if its below 1:1 ;)   Shame on Zeiss.

1:1 ratio is a subjective value. You get more magnification with 1:1 macro on crop, than with 1:1 macro on FF.
Something like A7R (36mp sensor) allows you to crop a lot and get the same magnification of a 16mp crop sensor. So, technically, 1:2 macro on 20mp crop provides similar magnification to 1:1 macro on 12mp FF.

1:1 has nothing to do with megapixels; it is entirely governed by optics and means the physical size of the projected image equals that of the subject, ie a 1cm tall object results in a 1cm tall projected image.

Due to the cropping factor of an aps-c sensor though, you are effectively blowing up the projected image. So this means that for a crop factor of 1.5, a 50 mm lens will become 75 mm equivalent, and at 1:2 magnification becomes 3/4 magnification.

Well, lens magnification has nothing to do with megapixels, but the amount of information you get from it depends on the number of pixels you put on each millimeter of the projection. I may be using wrong terminology here, I'm sorry for my bad english. IMHO, on different sensor sizes (FF, APSC, m4/3) 1:1 ratio has different values, as well as with different resolutions of the same sensor size, because, when it comes to the final (real macro) image, everything matters. At those magnifications I mostly care about the information I can capture with the final image in mind (on big display or print), not how big it looks on my camera LCD or in a smartphone snapshot gallery.

74
Third Party Manufacturers / Re: Samyang Teases New Lenses
« on: August 27, 2014, 09:52:55 AM »
There is no such thing as a "macro" if its below 1:1 ;)   Shame on Zeiss.

1:1 ratio is a subjective value. You get more magnification with 1:1 macro on crop, than with 1:1 macro on FF.
Something like A7R (36mp sensor) allows you to crop a lot and get the same magnification of a 16mp crop sensor. So, technically, 1:2 macro on 20mp crop provides similar magnification to 1:1 macro on 12mp FF.

75
Lenses / Re: A New Pancake Lens? [CR1]
« on: August 24, 2014, 11:03:28 AM »
I would love to have 20mm pancake on FF
I think we'd like a 20mm prime of any sort in FF.  Canon hasn't made a new once since 1992.
yeah a nice 20-21mm prime would be sweet - 21mm IS USM
pancakes at with canon's registration distance at 20mm? would have alot of compromises.
the Voigtländer 20mm 3.5 skopar is a good example. vignettes like hell, and blows the snot out at the corners.  it makes the 17-40 look good in the corners.
Not sure i would like that versus just having a regular 21mm as sharp as the other current 24,28,35 IS USM lenses - especially for under 1k.
unless this is an EF-S lens and if so, why 24mm? the same as 40mm on full frame perhaps?
for EF-S .. a more likely and needed lens would be a 30mm 1.8 EF-S IS STM  (IMO - but that's what everyone in the EF-S world usually complains about not having)
Canon 30mm F1.8 IS STM ... It would be a dream lens for me. ::) :-*

Not much different from EF 35/2 IS USM, is it? :)

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