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Author Topic: Why I need MPs  (Read 6674 times)

Denabears

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Re: Why I need MPs
« Reply #30 on: December 10, 2011, 05:26:14 PM »
What about post-processing?

Do increased megapixels give greater ability to process images?

It seems like people are discussing too many variables here.

PLEASE PEOPLE...

Is there an "all other things equal" way to compare different megapixel counts ???

All these formulas and extra variables mean 90% of people viewing this thread probably don't understand the discussion.

That's actually a really good point.   Extra pixels help preserve high frequency detail that would be lost when transformations are done e.g. to remove lens distortion, level a horizon etc. 

I'm sorry that by my mention of diffraction (which was not even necessary for my argument) I caused the thread to get messy - mea culpa.

Even better: I'll shut up, unless asked a direct question.
« Last Edit: December 10, 2011, 05:28:43 PM by Denabears »

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Re: Why I need MPs
« Reply #30 on: December 10, 2011, 05:26:14 PM »

Gothmoth

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Re: Why I need MPs
« Reply #31 on: December 10, 2011, 05:38:50 PM »
No, the wavelength is of course assumed constant  in the 3 point argument.  Which step don't you agree with?


ok.. once more before i go to bed. :)

my viewpoint is a viewpoint of the physical OPTIMUM.
i don´t care about how good the real lenses are.
for my argumentation i already have a PERFECT lens (because i talk about the OPTIMUM performance, the best theoretical possible performance). it´s a mathematical view on the best possible resolution.

so with a PERFECT lens i have a MINIMUM size of an Airy Disc.

the amount of detail a sensor will resolve will INCREASE when i make the photosites SMALLER.... UNTIL i reach a point when the photosites are SMALLER then the Airy Discs.

how much smaller is open for argumentation.
but you will reach that size at some point (btw: that is also why we need other devices then visible light microscopes. because they are limited by the the wavelength of visible light).

so once we have reached that size we can make the photosites on the sensor smaller and smaller but we will NOT resolve MORE detail. at this point you can increase the megapixels (the theroretical sensor resolution) but the output resolution (real information) will be stagnating.

that is because ot the mathematical formula given in the wikipedia article.

the only way you can resolve more details with smaller photosites at this point is when the wavelength of the rays you collect with your sensor will be smaller/shorter (ultraviolett for example).
because a shorter wavelength creates a smaller airy disc with a given aperture.
 

 
« Last Edit: December 10, 2011, 06:18:29 PM by Gothmoth »

CanonLITA

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Re: Why I need MPs
« Reply #32 on: December 10, 2011, 06:17:58 PM »
Is one or more of the following correct?

1. even assuming a perfect lens, there will always be a minimum size of the resolvable light information (due to the way light waves behave when they pass through the lens aperture and are forced to change their direction - i.e. difraction) and therefore no more information would be captured be decreasing the size of the pixel below this physical threshold;

2. the minimum useful size of a pixel (as per 1 above) is so small that nowaday we are pretty far from it and it still makes sense (resolution wise, please disregard cost) to squeeze more than 21mp in a FF sensor;

3. even when the minimum useful size of a pixel (as per 1 above) is reached, squeeze more pixels in the sensor still makes sense (resolution wise, please disregard cost) to (a) better post processing, and/or (b) overcome the limits of a real-world-less-than-perfect lens.

Thank you all for your thoughts.

Gothmoth

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Re: Why I need MPs
« Reply #33 on: December 10, 2011, 06:26:08 PM »
Is one or more of the following correct?

1. even assuming a perfect lens, there will always be a minimum size of the resolvable light information (due to the way light waves behave when they pass through the lens aperture and are forced to change their direction - i.e. difraction) and therefore no more information would be captured be decreasing the size of the pixel below this physical threshold

correct and that is why at some point a visible light microscope is not good enough.
the wavelength of the visible light is limiting the size of the structures we can resolve with a visible light microscope.

Quote
2. the minimum useful size of a pixel (as per 1 above) is so small that nowaday we are pretty far from it and it still makes sense (resolution wise, please disregard cost) to squeeze more than 21mp in a FF sensor;

in theory yes (if you use big apertures and not f13 and smaller).  (*)
but in the real world we have to keep lens imperfections, noise etc. in mind.
so 21MP is not near the limit but with todays technology i question the usefulness of 36MP or even 45MP FF sensors.

(*) with small apertures you are today limited even with a perfect lens.

Quote
3. even when the minimum useful size of a pixel (as per 1 above) is reached, squeeze more pixels in the sensor still makes sense (resolution wise, please disregard cost) to (a) better post processing, and/or (b) overcome the limits of a real-world-less-than-perfect lens.

kind of.
in a perfect world (theoretical world) more photosites would not make things worse.
but we don´t live in a perfect world. ;)

(a) the size of the files will be bigger -> slower to process in camera and on the PC, more storage space needed. but no real gain on information.

(b) in theory yes. but i doubt that you will see it.
i mean look at the 18MP 7D... crap lenses make no visible better images with that camera.
« Last Edit: December 10, 2011, 06:41:24 PM by Gothmoth »

Richard8971

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Re: Why I need MPs
« Reply #34 on: December 10, 2011, 09:00:53 PM »
I can't tell you how many times I see guys out shooting who have high $$$, high MP cameras/L glass who can't shoot their way out of a wet paper bag. It is far better to KNOW your equipment, regardless of what EOS body you use and use it frequently!

I have gotten outstanding photos from my XTi through my 7D. My wife still loves her T1i that we bought new 3 years ago and refuses to upgrade to a "pro" body. I only got my 7D because my 40D was damaged beyond repair, not because I needed/wanted a higher MP camera.

Truth of it is, the higher the MP, the better the glass needs to be to take full advantage of the higher pixel count. Hand shake CAN effect the quality of the photos, regardless of IS or not. Unless you are doing SERIOUS cropping (and if you do, maybe you should buy the lens you really need for the job vs cropping) I really doubt you would ever notice how many MP there were in the PRINTED photo taken from ANY camera.

Guys, the only time you ever really NOTICE the resolution is when the photo is on your monitor and you are scrolling in to each and every pixel. Take a 8-10MP rebel and take a photo. Take the same photo with a 18MP 7D and have 8x 10's made. I doubt you would ever really be able to tell them apart. The 40D vs 50D was a great example of this.

I am still a huge believer that good glass & knowledge of your equipment is far superior to high MP camera bodies. If you are buying a new camera, buy the one that you can AFFORD and best suits your needs, regardless of MP size. (IE, 6.5fps 40D vs 8fps 7D, these are very fast cameras and about a grand difference between the two. BOTH produce outstanding images! You do the math.) If you already have a camera, keep it and learn it WELL! Only upgrade if your current camera cannot keep up with your needs, not wants. But, of course, if you have plenty of money and a budget isn't of concern to you, none of this really applies. I am mainly speaking to the working folk of the world on this point. If you make your living with photography then I would still say the same. Buy what you can afford and learn it!

Will any of this stop the MP race? No, and it shouldn't. Cameras will continue to advance and grow in MP. I think however, that more and more people are starting to see that the QUALITY of the photo (regardless of MP size) is far more important than the SIZE of the photo. Right now, the technology is set to do just that and Canon has led the way with the new 1D X by changing people's perception of needing higher and higher MP!
« Last Edit: December 10, 2011, 09:54:29 PM by Richard8971 »
Canon 5D2, 7Dv2.03, 50D, 40D, T1i, XTi...XT (& lenses, flahses), various powershots... You get the idea... I have a problem. :)

Wife shoots Nikon, D7000, D7100, (lenses and flashes)... we constantly tease each other that our cameras are better than each others!

Richard8971

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Re: Why I need MPs
« Reply #35 on: December 10, 2011, 09:37:59 PM »
I do have to add one point. I would say that the question SHOULD be, not the size of the MP of a sensor but the SIZE OF THE SENSOR!

In other words, FF vs crop sensor. Now, that being said, the original Rebel at 6MP has about the same pixel density of the FF 5D at twice the resolution. Both produce very clean images at similar ISO settings. I'm not talking about cropping, scrolling down to each pixel, blowing up the image... yada, yada, yada. I am simply talking about taking a photo and having a 4 x 6 made!!! I bet you would be hard pressed to tell them apart.

Pixel density has a greater effect on image quality over MP size of the sensor! Unless some breakthrough takes place in CMOS/CCD techology, it will be this way for a long time.

At this point in camera tech, FF produces smoother photos than a crop sensor with the same resolution at higher ISO settings with similar lenses. Just the way it is...

D

Canon 5D2, 7Dv2.03, 50D, 40D, T1i, XTi...XT (& lenses, flahses), various powershots... You get the idea... I have a problem. :)

Wife shoots Nikon, D7000, D7100, (lenses and flashes)... we constantly tease each other that our cameras are better than each others!

dtaylor

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Re: Why I need MPs
« Reply #36 on: December 10, 2011, 09:52:44 PM »
but in the real world we have to keep lens imperfections, noise etc. in mind.
so 21MP is not near the limit but with todays technology i question the usefulness of 36MP or even 45MP FF sensors.

People keep debating the maximum useful FF resolution without considering what we know from APS-C.

The 7D and 5D2 are pretty close in terms of MP (18 and 21). Having a smaller sensor, the 7D is like a crop from a 45 MP FF sensor.

If real world lenses and shooting conditions would render 45 MP of little or no benefit on FF, then they should impact the 7D to the same degree. In other words, even though the 7D and 5D2 are close in terms of MP, their actual performance on resolution charts should be much further apart if the 7D is hobbled by lenses and shooting conditions.

DPReview has tested the resolution of both bodies. They typically stop down to f/8 in these tests. They are:

7D Absolute Extinction (JPEG test)
H 2500 3100
V 2450 3050

5D2 Absolute Extinction (JPEG test)
H 2800 3300
V 2700 3300

Note: I'm using the JPEG test numbers because DPReview didn't do a RAW resolution test on the 5D2. RAW numbers would be a bit higher because ACR is better at resolving fine detail then Canon's JPEG engine / DPP, but the relative difference would remain the same.

The difference in measured resolution is actually a bit less (<12%) then we would expect based on the MP difference (16%). This is real, hard, observed data. If your theory conflicts with it, your theory is wrong, not the real world experience.

The 7D sensor is not limited by the 50mm f/1.4 @ f/8. That's a very good lens at f/8, but it's hardly the only lens that can resolve that much detail, and f/8 is actually just touching on diffraction effects for the 7D's pixel density. This tells us that a 45 MP FF sensor would be quite useful.

How useful? Stitch three 7D frames together overlapped so that you end up with roughly 45 MP. The resulting image will out resolve 6x7 film on an Imacon, and resembles the 645D sample images I've seen in terms of sheer detail and clarity.

Not everyone needs this. Many people would love it. That's why Canon needs a fast shooting/low light FF sensor (1Dx) and a high resolution FF sensor.

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Re: Why I need MPs
« Reply #36 on: December 10, 2011, 09:52:44 PM »

dtaylor

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Re: Why I need MPs
« Reply #37 on: December 10, 2011, 09:57:00 PM »
Guys, the only time you ever really NOTICE the resolution is when the photo is on your monitor and you are scrolling in to each and every pixel. Take a 8-10MP rebel and take a photo. Take the same photo with a 18MP 7D and have 8x 10's made. I doubt you would ever really be able to tell them apart.

I make 16x24" and 20x30" prints. The last two portfolios I made were 17x22. I guarantee you I could tell them apart.

Richard8971

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Re: Why I need MPs
« Reply #38 on: December 10, 2011, 10:21:15 PM »
Guys, the only time you ever really NOTICE the resolution is when the photo is on your monitor and you are scrolling in to each and every pixel. Take a 8-10MP rebel and take a photo. Take the same photo with a 18MP 7D and have 8x 10's made. I doubt you would ever really be able to tell them apart.

I make 16x24" and 20x30" prints. The last two portfolios I made were 17x22. I guarantee you I could tell them apart.

??? The statement I made was regarding 8 x10's, not prints that large.

And for the record, I have prints in my studio that I have made from my lowly 10MP XTi as large as 16 x 20 that I would put against ANY camera, regardless of MP. Here are a few that I have made large prints from. Mind you, I had to compress them down a tad to allow the 'CR' server to accept them but trust me, there is NO loss of detail or "crispness" in the full size prints! (The ones I posted are jpeg's at 25% compression!)
« Last Edit: December 10, 2011, 10:56:22 PM by Richard8971 »
Canon 5D2, 7Dv2.03, 50D, 40D, T1i, XTi...XT (& lenses, flahses), various powershots... You get the idea... I have a problem. :)

Wife shoots Nikon, D7000, D7100, (lenses and flashes)... we constantly tease each other that our cameras are better than each others!

archangelrichard

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Re: Why I need MPs
« Reply #39 on: December 10, 2011, 11:52:42 PM »
The OP asked a practical question and got an awful lot of impractical answers (a long with a very few practical ones - like Danabears first response)

Look here, folks. FILM is a monstrously higher resolution (anyone who doubts this, try enlarging a sharp film negative to 48 inch x 60 inch - then try doing so with a digital print ... at 1200 dpi for high quality to match the film as close as you can (my printer does 9600 dpi!) and look at the results)

Remember lenses worked to get that sharpness in film; should be able to achieve the same in digital so the lens is NOT the limiting factor; at least not in the way many have stated here (however chromatic aberrations are different for film over digital so that may cause some issues)

So, to the OP; YES what you say is true and it  is possible at some point in time that this will happen - but not with today's technology. In medium format you can go with an 80 MP mamiya / Phase One (645 means 60mm x 45mm sensor size); there can be incremental increases in MP count in 35mm format but you are not going to see anything like 80 MP any time soon - that 80mp sensor is a density of 25.6 MP for FF sensors so we know that this is possible easily and we can see the quality of it; above that there are a lot of guesses of 32 - 36 MP's being possible / practical / pending - see all the rumors on this site

NO we are nowhere near the limits of possible technology as many here would like to think; more is definitely possible; but you could be talking of different materials for sensors, etc. to get much higher; Yes for the purpose the OP mentioned, more resolution / more MP is possible and will help in your work as you need to crop (and ignore the insults you have been getting about reframing, etc. from people who failed to read and comprehend the Original post); it just won;t be that soon

Richard8971

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Re: Why I need MPs
« Reply #40 on: December 10, 2011, 11:55:39 PM »
Sadly, the battle of higher MP and FF vs crop sensor will go on and on as long as Canon, Nikon and others produce different camera bodies with different features.

Is there any one right answer? No. If there was, and I knew it, I would be a very, very, very rich man today.

The bottom line is, no matter what you know, or think you know, no matter how much money you have or don't have, no matter what camera body you own and no matter what lenses you own or don't is this... Learn the equipment that you DO have and learn it well. If you do... you will be in the position when the time comes to take that ONE perfect photo and make it shine. Be happy and grateful for the equipment that you DO have! That I DO know...

Photography is fun... continue to make it that way! :)

D
Canon 5D2, 7Dv2.03, 50D, 40D, T1i, XTi...XT (& lenses, flahses), various powershots... You get the idea... I have a problem. :)

Wife shoots Nikon, D7000, D7100, (lenses and flashes)... we constantly tease each other that our cameras are better than each others!

Richard8971

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Re: Why I need MPs
« Reply #41 on: December 11, 2011, 12:10:28 AM »
The OP asked a practical question and got an awful lot of impractical answers (a long with a very few practical ones - like Danabears first response)

Um, the OP said this...

"Just because I like to throw fuel on the flame...

There are so many discussions about needing more megapixels with strong proponents on each side, I thought I'd join the fray with some specific examples (especially because it seems like most of the "I need MPs" side is landscape photographers of which I am most definitely not.)

Below I am posting the crop image and then the original.  Again, my context is that capturing a decent shot of every athlete in the race is my number one priority.  There is little to no time to worry about doing anything artistic, and often even a basic reframing of the shot is more work that I seem to have time for.  So some of these are cropped because I think there is artistic value in the a portion of the original image (and 500 shots of "runner...runner...runner...runner" gets old without some creativity  ), or as one example shows, simply to isolate the given athlete.

I'm open to contructive criticism if there are things I could do differently to reduce or eliminate my "need" for more MPs (or any other photographic/artistic feedback)."


I would believe that most, if not all of the posts here answer his question. He says he uses the XTi and 40D (both of which I have owned and loved) and wants to know how he can improve on it. Does he need more MP? Hard to say... why? I still believe that glass is more important that camera body. Look, I have seen OUTSTANDING, crisp images taken from a 40D using the 100-400L lens. 10MP guys... great images, just like ones I have taken with my XTi. :)
Canon 5D2, 7Dv2.03, 50D, 40D, T1i, XTi...XT (& lenses, flahses), various powershots... You get the idea... I have a problem. :)

Wife shoots Nikon, D7000, D7100, (lenses and flashes)... we constantly tease each other that our cameras are better than each others!

neuroanatomist

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Re: Why I need MPs
« Reply #42 on: December 11, 2011, 09:45:24 AM »
I still believe that glass is more important that camera body.

Bingo.  Put a good lens in front of a sensor, and the effects of increasing pixel density will be subtle, at best.  Put a crappy lens in front of a sensor, regardless of the pixel density, and the image will be worse.
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Re: Why I need MPs
« Reply #42 on: December 11, 2011, 09:45:24 AM »

thepancakeman

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Re: Why I need MPs
« Reply #43 on: December 12, 2011, 11:55:06 AM »
Wow, this thread did not exactly go how/where I'd planned.

There is now another thread on the topic here: http://www.canonrumors.com/forum/index.php/topic,2424.0.html.

I was trying to add a different slant to the MP crowd, as it seems most of them are landscape photographers and their cries for higher MPs is answered with "hey there are a lot of great landscape photos out there that don't have high mps, so what you really need is better ISO or DR performance".  There are (or were) a few billboard photographers out there as well, and the response to them was "people shouldn't be looking at your billboard that close anyway."  I am attempting to add a 3rd category to the high MP crowd as those of us who "NEED" (?) to be able to do fairly extensive cropping after the fact.  I have heard a few fashion photogs jump in in this category as well, and I was just trying to provide some concrete examples (plus maybe solicit some feedback on my images.)

I did get the expected response of:
learn composition in camera.

While I'm happy to oblige, I think the challenge is summed up pretty well here:
So the OP is supposed to compose 8 different pictures, of different objects, who are moving 10-30/mph(runner vs. biker), in a matter of a few seconds

I think this is an interesting suggestion:
And one more idea: maybe buy a 1DX and use it in video mode.  The video resolution might be high enough to let you "sweep" a group and get multiple useable still shots.
Has anyone done or tried that?  My one concern would be the time and effort of wading thru the video to ferret out the few that I missed in the stills.

The sample posted by wellfedCanuck is not atypical of race photos.  IMHO, the entire photo is fairly weak, and the only 1 of the 7 runners in the photo would likely be interested in purchasing a copy (my principle clients are the athletes themselves.)  So if that's the shot I walk away with, I just lost 86% of my potential customers.  I think it can be done better.

As a side note relating to neuro's comment--yes distribution does depend on capturing bib numbers, as well as the fact that most runners seem to prefer photos that are framed to include their feet.  So between the athletes themselves and the race directors, the full body shots are my "expected" output, the headshots/crops are "bonus" items.

Let me explain my methodology, and perhaps there are other good ideas on how to better accomplish the task (aside from getting a Nikon D800  :o ).  I am nearly always shooting with the 70-200 f2.8 IS.  When I have a large group coming, I start at 200 and pan back as the group approaches trying to anticipate where gaps might open up so that I can isolate individual runners.  When there's clearly no way to pick them off one by one, I will stop down and try to frame 2 or 3 in focus at the same time (hence the cropping, hence the needing more MPs).  Where I am really open to ideas, is how to balance everything:  I usually shoot at 2.8 because I need a high shutter speed to freeze the motion.  In my (albiet limited) experience, cyclists require a bare minimum of 1/250, with more reliable results starting at 1/800; runners I can get away with 1/125 if there are no other options, but prefer about 1/400.  When I stop down it's because I'm going to end up cropping, so then a higher ISO becomes an issue because the noise is more evident in the cropped result.

Of course, maybe a "dude, your crops suck even worse than you originals, so don't bother" would solve the problem too.   ???

Firstly remember what is expected of you. Practice composition in camera so you don't have to crop in post because this takes forever for a few thousand pictures. If the client wants to publish any pictures he will crop them anyway, and usually not very artistically.

For your own portfolio, pick a few of the best and edit these more thorougly, including crop, angle, spot removal, vignette, etcetera. 10 MP should still be enough for a web portfolio and smaller prints (up to A4). If not then your upcoming 7D might be the right solution for you; I would have suggested renting it otherwise.

Yup, post processing a few thousand pictures every event does take forever.  Yes, I race directors like a few "poster" shots for their websites and advertising, but most of my revenue comes from the individual participants, so the balance is between quality of shots and missing shots.  I'm of the mind that a decent shot of nearly every athlete is going to generate more revenue that fabulous shots of a few athletes.  But if I can crop some to get those better shots, it's a big plus.  However, I'm still very new to this, so if there's a better way to sell/market my photos I am all ears!  I've gotten really positive feedback from the few races that I've done, so I think I'm on the right track, but there's always room to do it better, more efficiently, and hopefully more profitably.

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Re: Why I need MPs
« Reply #44 on: December 12, 2011, 01:15:17 PM »
I think this is an interesting suggestion:
And one more idea: maybe buy a 1DX and use it in video mode.  The video resolution might be high enough to let you "sweep" a group and get multiple useable still shots.
Has anyone done or tried that?  My one concern would be the time and effort of wading thru the video to ferret out the few that I missed in the stills.

It don't know if it would work for your workflow, but maybe hire a kid at $10-$15/hr to scan the entire video and enter bib#'s and time slots into a spreadsheet.   When someone sends you their bib# and asks, you can look it up in the spreadsheet and go straight to the right timeslots.

You could get some friends to help you test technique and workflow with your current camera.  Obviously, image quality will be very different, but it would give you an idea if it's feasible.

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Re: Why I need MPs
« Reply #44 on: December 12, 2011, 01:15:17 PM »