5DmkII less sharp than 5D!

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Archive 2008 · 5DmkII less sharp than 5D!

vkalia
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p.4 #1 · 5DmkII less sharp than 5D!

stockriderman wrote:
100% crop of 12mp should not be any sharper than 100% crop of a 21mp. This is the reason why reviewers do this so call "mistake" I don't want to buy a 21mp camera so that it would only be as sharp as 5D at 12mp. I want it to be just as sharp at 100% crops as well. Otherwise, why not just re sample the 5D images via photoshop!!
OP,s view doesn't make any sense

Well, if your goal is to compare 100% crops, then yes, you are right. Brainiac's view doesnt make sense.

But for most people, the goal is prints. With any image, the goal is a certain sized print - be it 4x5, 16x20, 4'x6', billboard or whatever. When you compare 2 cameras, what you are trying to figure out is how well the prints from the 2 cameras would match up (at that chosen print size).

In such a case, it makes more sense to compare the 2 cameras with one image up-rezzed to the other (not down-rezzed - that destroys information and also leads to blindness and hairy palms, I think). This gives you a better idea of how the 2 cameras stack up.

It is a bloody shame that camera reviews today seem to be driven by the 100% crowd, most of whom dont appear to actually make large prints or actually use the camera in real-world conditions. It affects those few remaining people who actually seem to care about images and prints, b/c it forces manufacturers to re-allocate their priorities to appease the pixel-peeping vocal minority/majority.

I've already ranted about this in another thread, but I read these posts from people who need 100% weathersealing and wonder if they have actually ever shot in the rain - what they do with water droplets on the front element and viewfinder window, for example. And for those people who apparently shoot fast-developing action and at the same time want AF points on the edge of the image frame (!!!). My best-selling action shot to date was taken with an Elan IIE (3 AF points, 3fps).

Anyway, I digress. Coming back to the subject - I hope it makes sense now why 100% is not the best arbiter of IQ.

Vandit

Edited on Sep 19, 2008 at 08:49 PM · View previous versions

Sep 19, 2008 at 08:04 PM

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p.4 #2 · 5DmkII less sharp than 5D!

DoubleNegative wrote:
Photon wrote:
Sigh, life was so much simpler when we waited a few years for film manufacturers to improve color, grain, ISO by some small amount, and plastered the magazines with ads about revolutionizing photography...

Not that I want to return to any "simpler times", no way, no how!

Actually, they did... Kodak is coming out with Ektar 100, due in October or November. Promises to be VERY good (better than Ektachrome E100G) and replaces the Ultra Color UC100/400 films.

Fuji I believe is also fully comitted to film, mentioning something recently.
My point is that before digital matured, it was understood that to get a major improvement in print quality you moved to a larger format. There were periodic improvements in film emulsions, but they were generally more subtle than some of the jumps in sensor technology that seem to show up about every two years. We can now get print quality out of a 24x36 mm ("FF") sensor that would have required a large format scanning back about 10 years ago (no hope of action stopping location exposures).

Regarding all the fuss over whether to compare cameras by uprezing the smaller file to match the larger - remember when the 4 MP 1D had been around for a couple of years and people would say "why bother with that when you can get 6 or 8 MP for less money?" Users of the 1D would reply that its images responded well to interpolation, and made clean large prints. (They still do, within reason). No one was complaining how unfair it was to upres the 1D to match a 20D or whatever. I see nothing spurious about upresing 5D or D3 images either. Make the prints if you have the chance and don't mind the small expense.

Also, I wouldn't form any negative ideas about 5DII sharpness until I'd seen well exposed raw files using great lenses and careful technique.

Sep 19, 2008 at 08:27 PM

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p.4 #3 · 5DmkII less sharp than 5D!

That was well written and discussed. BUT, are you suggesting that for some lenses we may get a better resolved image if we were to use sRAW v RAW with the 5DmkII?

Gil

Sep 19, 2008 at 09:07 PM

dennysb
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p.4 #4 · 5DmkII less sharp than 5D!

brainiac,

Thank you so much for putting this much useful information. I too have a 1Ds MarkIII and distinctive remember all the forums talk about lack of sharpness without taking into consideration the 21MB image size.

Buying this new 20+ MB bodies is like buying a JET. If you think you are done expending the big money because you got the JET (Body) , you are wrong

You just starting to spend money - You are now obligate to buy the best glass so you can justify the body. Point in case My 16-35L did decent on my 5D camera, but no-way I would use it on my 1Ds Mark III. I have several friends that had to get rid of many lenses that just don't cut it when used with the 1Ds Mark III, and that is attributed to the fact that many of the optics flaws on the current glass offerings are better noticed with this new superMB bodies.

THX!

Sep 19, 2008 at 09:21 PM

dasrocket
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p.4 #5 · 5DmkII less sharp than 5D!

hmmm: try 16"X20" black and white prints.

I recently looked at side-by-side portraiture prints from a phase one and a D3 and, as one in the group rightly commented: "...the D3 print shows a perfect picture of hair. The Phase One print shows hair..."

Having said that, one of the D3 prints was 24"X36" and it held up pretty well on that size.

Sep 19, 2008 at 09:34 PM

dasrocket
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p.4 #6 · 5DmkII less sharp than 5D!

here is the irony (brainiac, that's why your OP was doomed

):

We now have a heated multipage sharpness argument about avoiding a multipage sharpness argument! (where is that "hit my head on the wall" emoticon damnit?)

Sep 19, 2008 at 09:42 PM

DavidB
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p.4 #7 · 5DmkII less sharp than 5D!

jvarszegi wrote:

You're failing to account for the fact that there is a middle ground between perfect sharpness at 100% on a 12 MP sensor and perfect sharpness at 100% on a 21 MP sensor. One of the things brainiac says is that a lens may out-resolve a 12 MP sensor but not a 21 MP sensor.

Exactly. Whereas previously with a given lens and the 5D you may have been limited by the resolution of the sensor, it's likely with the 5DmkII that you will be limited by the resolution of the lens instead.
It might not look as good viewed at 1:1 of a 21 Mp file compared to 1:1 of a 12 Mp file, but our hope is that for a given area of the scene, the 5DmkII will resolve more detail. Hopefully no-one will dispute that?

As long as the images are better, people should be happier. Never mind arguments about the linear resolution of the sensor only increasing by 29% (sqrt(21.1/12.8), or just 4368 -> 5616 pixels) which are perfectly true, the bottom line is that the final result should be an upgrade (not by how much).
Not everyone's going to see it that way though.

At least we have a previous example of a 21 Mp camera to use as a comparison!

Sep 19, 2008 at 10:30 PM

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p.4 #8 · 5DmkII less sharp than 5D!

snowboarder wrote:
brainiac wrote:
I was downrezzing ... the other day, when my wife walked into the room. She looked ... and the downrez had turned ... into harcore porn...

Dude, what are you talking about?

I am trying to parody, by reductio ad absurdum, the disbelievers in resizing. My point is, simply, that resizing images doesn't particularly harm the data. Uprezzing gives you the same image, and a certain amount of redundancy in the pixels, since there are more of them than the data volume would require. Downrezzing takes away detail, but otherwise gives a very faithful version of the image with the high frequency stuff removed. In crude terms, downrezzing is lossy; uprezzing isn't. The argument that doing either of these processes somehow nullifies the result seems entirely bogus to me, especially since every printer rasterises/interpolates pixel data into ink commands before printing. If interpolation was such a fiction, it would be impossible to use your monitor to adjust an image for printing. Uprezzing a 12 megapixel file to 21 megapixels isn't destructive. Print a 12 megapixel file at 16x24, then uprez it to 21 megapixels, print again, and see if there is a visible difference. There won't be, unless your printer is sharp enough to resolve the pixel edges. Uprezzing or downrezzing a landscape does not turn it into porn.

Sep 20, 2008 at 01:06 AM

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p.4 #9 · 5DmkII less sharp than 5D!

LiquidAir wrote:

It is VERY IMPORTANT TO REMEMBER THAT WHEN YOU EXAMINE 100% CROPS FROM A 21 MEGAPIXEL CAMERA YOU ARE VIEWING THE IMAGE AT SIGNIFICANTLY HIGHER MAGNIFICATION THAN YOU ARE USED TO. This means that although the lens defects and noise are more visible in 100% crops, the print is still better than you were getting from your 12 megapixel camera. A 100% crop of a 21 megapixel file is a much higher level of scrutiny. The per pixel noise doesn't need to be as good as that in a 12 megapixel file in order for the file to equal or surpass the lesser file's noise footprint.

If you are comparing full frame bodies, what you say is true. However all of Canon's current APS-C crop bodies (40D, 400D, 450D and 1000D) have a higher magnification than the 5D2. If you put the same lens on a 40D and a 5D2 it will look slightly sharper in the center of the 5D2 frame.

The size of a sensor makes a great deal of difference to the number of photons captured, and therefore the likely noise levels. However, once the image is captured, you have a certain number of pixels in it. At that point, it can be fairly compared on screen with other files, by resizing them all to the same number of pixels, and the size of the capture device no longer has any significance.

Sep 20, 2008 at 01:10 AM

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p.4 #10 · 5DmkII less sharp than 5D!

true, plus just logically speaking how can it possibly pick up less detail? Same size sensor and more pixels, even if they didn't pick up too much more they can't hurt the sharpness and since the AA filter can be weaker if anything, you should pick up a trace extra sharpness and even with bad lenses the extra pixels would sort of super-sample the image and help a trace, but, unless they went to some really harsh AA filter for some unknown reason (althogh actually the 5D had such a weak one perhaos this IS possible actulaly), it just can't happen.

under really low light conditions smaller pixels might be a touch worse since they are not gapless and small pixels tend to have worse read noise than larger pixels in the electronics so it could be a touch less sharp under really low light, but at 2x the pixels it is very, very unlikely the negative aspects could ever be so extreme as to actually make this true.

anyway, it's exceedingly unliekly that the 5DmkII would be less sharp the 5D under ANY condition using ANY lens.

Sep 20, 2008 at 01:10 AM

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p.4 #11 · 5DmkII less sharp than 5D!

philber wrote:
Brainiac, I take your excellent point and thank you for the info. The only issue I fail to get my head around is the "uselessness" of more pixels. Let's say we compare 2 shots from 5D and 5DII, 21Mp rather than 12 Mp, without cropping and that we print on A4 paper. The 21Mp picture is going to mean many more smaller pixels than the fewer larger ones from the 12Mp sensor, irrespective of print size. If it is meaningless, it means that either paper, printer, or both, are incapable of matching any resolution higher than 12Mp in A4 size. So we should be working hard at finding either better paper and/or better printers. Which we don't seem to be busy doing.

We are busy doing that, and each new generation of Epson or Canon ink printer that emerges is sharper and better than the last. The papers have been advancing rapidly too.

Conversely if more pixels make a difference, it should be visible in transition zones between volumes, objects and colours, which should be more "brutal" on the 12Mp sensor, and more delicately progressive and shaded of the 21Mp. Again, if it were meaningless, it would mean that a print off a 1DIII should be exactly the same as that off a 1DsIII, or a 5D and a 5DII unless you crop massively or print very large, not considering noise, ISO and DR.
Can you help me understand this better?

I remember getting a 12x8 print made from a 5D file which I had modified with some white text on a dark background. I noticed on screen that along the bottom of one of the letters there was a single pixel step in the almost horizontal white line. It was not aliased. I was amazed to find that I could clearly see the step in the 12x8 inch print. You don't have to go very big before you can actually see each of the 12 million pixels. 21 million just means more detail, and I know for a fact that this difference in detail is visible on a basic A3 gloss print from an Epson R1900. 21 megapixels isn't just an advantage for 40 inch prints, although the bigger you go, the easier it is to see what's missing in the 12 megapixel version.

>And thanks agains for the excellent thread.

It's a pleasure to discuss these things with you.

Sep 20, 2008 at 01:18 AM

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p.4 #12 · 5DmkII less sharp than 5D!

stockriderman wrote:
lol
100% crop of 12mp should not be any sharper than 100% crop of a 21mp. This is the reason why reviewers do this so call "mistake" I don't want to buy a 21mp camera so that it would only be as sharp as 5D at 12mp. I want it to be just as sharp at 100% crops as well. Otherwise, why not just re sample the 5D images via photoshop!!
OP,s view doesn't make any sense

LOL - no, it's your method that doesn't make sense. If you want to compare two cameras with different numbers of pixels, then it's important to be able to see any higher sharpness that the higher resolving camera delivers. THE ONLY WAY TO DO THAT, WHEN LOOKING AT 100% CROPS, IS FIRST TO RESIZE THE LOWER RESOLUTION FILE UP TO THE SAME PIXEL DIMENSIONS AS THE HIGHER RESOLUTION FILE. Otherwise, given a perfect lens, a 6 megapixel file will appear to resolve just as well as a 100 megapixel file. At that point you would recommend the 6 megapixel file because it's cheaper, and by your fatally flawed method of comparison, just as good.

In contrast, by my method, if the uprezzed file turns out to be just as good as the 100% crop from the higher resolution file when they are both viewed at 100%, THEN YOU CAN SAY THAT THE HIGHER RESOLVING CAMERA BRINGS NO ADVANTAGE, FOR WHATEVER REASON (typically the lens). The reason why reviewers, and you, make this mistake, is that you are confused. Your method of comparison always favours the lower megapixel file, because that is the least magnified image from which a crop is being viewed. By your method, the 1 megapixel file always ends up beating the 100 megapixel file. The pixels put less pressure on a lens, and are likely to be less noisy. That has little bearing on the final image quality. Of course, you are free to go on making that mistake, but believe me, it is a mistake.

Sep 20, 2008 at 01:32 AM

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p.4 #13 · 5DmkII less sharp than 5D!

Steve Spencer wrote:
brainiac wrote:

Well, I correctly predicted, in November last year, that the 1Ds3 would have a comparable noise performance (providing you want to make pictures, not crops) to the D3. I am going to be bold and make another prediction here: the 5D2 iso 12800 noise performance, optimally processed from raw, will look pretty much the same as that from the 1Ds3. Why?
(1) because Canon likely made some effort with the 1Ds3 sensor, so tweaks are unlikely to radically transform its performance, and
(2) sensor design and fabrication is a very expensive business in which costs are acutely sensitive to volume, so Canon would be foolish not to aim to use its latest sensor in more than one model at different price points, if it can get away with it, and
(3) Canon has stated that the 5D2 sensor is derived from the 1Ds3 design, and
(4) no detailed explanation has been offered of how the 5D2 sensor differs from that in the 1Ds3, a

Hi Richard,

Interesting analysis, but have you seen this description of the sensor from Rob Galbraith's web site:

"With a size of 24 x 36mm, 21.03 million image pixels and a pixel pitch of 6.4µm square, the 5D Mark II's CMOS sensor offers the identical pixel count in a sensor that's identical in size to the full-frame EOS-1Ds Mark III. The 5D Mark II's sensor also features the same light-gathering area within each pixel (called the fill ratio) and same microlens coverage over each pixel as the company's current flagship.

To achieve what Canon is saying will be the highest image quality and lowest noise ever to emerge from a Canon EOS digital SLR, they introduced several refinements: the array of red, green and blue coloured filters over the sensor have been made more transmissive, which effectively bumps up the sensor's light sensitivity, plus they tweaked the way the sensor's signal (the light it has gathered during the exposure) is amplified and then read out.

Canon is showing some serious confidence in the 5D Mark II's image sensor, and in particular its noise characteristics: they've given the camera an extended ISO range of 50-25,600, which is a three stop jump from the ISO 3200 upper limit of the EOS-1Ds Mark III (and the 5D as well).

The 5D Mark II incorporates Canon's Integrated Cleaning System in front of the sensor, but with a new anti-stick fluorine coating on the frontmost filter surface that's meant to better prevent slightly moist debris from clinging on, or for it to be more readily shaken off during a cleaning cycle."

If they made the filters more transmissive, then there might be real improvement in ISO performance. I think we will have to wait for real side by side test to really know.

I agree. I really hope there is an improvement, because I will benefit from it, but so far I haven't seen any particularly impressive high iso shots from the 5DmkII. They look to be on a par with the 1Ds3, and the in-camera noise reduction looks unfinished. As you say, we shall see.

Sep 20, 2008 at 01:44 AM

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p.4 #14 · 5DmkII less sharp than 5D!

brainiac wrote:
Here's an iso 6400 comparison with the D700:
http://www.flickr.com/photos/erikfive/2868125472/sizes/o/

In that example the blotchy colour noise in the 5D2 file looks pretty bad. Has it been resized down to 12 megapixels to match the D700 file? We don't know, but we do know is that at iso 12800 the D700 and downsized, NR'ed 1Ds3 comparison looks like this:

From the author of that test on Flickr (when asked about the resizing) :
"I didnt downsize them. My buddy did, but I guess they are basically downsized to match each other yes."

Sep 20, 2008 at 02:50 AM

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p.4 #15 · 5DmkII less sharp than 5D!

brainiac wrote:

Lenses like the 24-105 are unlikely to take full advantage of the 21 megapixel sensor. Depending on the aperture, some significant part of the frame will be resolved at less than 21 megapixel resolution. .

You know, I have no problem with the rest of your (excellent) post, and I know you're a really smart fellow with lots of photog experience, but I can't let the second-half of that statement slide.

BA-LONEY. (I say fearlessly, hiding behind the mask of forum obscurity knowing full well that there's small chance you are actually correct.)

Even a Sears lens will be resolved at 21 mp. Lenses do not have megapixel limits. They are analog. Their resolution is surely finite, but it tails off gradually, and can't be measured in units such as mp. Whatever is put in from of the sensor will be resolved at 21 mp, even if it's a lens smeared with vaseline.

Now, I have no problem with you stating that a 21 mp sensor will be able to show the limitations of the 24-105L, but that is NOT the same thing.

Here's an important related question: Let's say, for the sake of argument, that the 5DII's sensor truly is superior in every way to the 5D's sensor. (very likely, though not yet proven.)
You take a detailed shot with the lowly" 24-105L, heck with the Sears 24-300mm, on both cameras, and you do the uprez dance on the 5D image. Then you do a 100% crop on each. Forgetting the 14-bit thing for a moment, are you claiming that the 21 mp image will look no better?

If so, I throw down the gauntlet in challenge, good sir! THIS, I wanna' see proof of.

Sep 20, 2008 at 02:51 AM

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p.4 #16 · 5DmkII less sharp than 5D!

Seems easy enough to prove right? Surely someone must have a 1ds3, 5d, and a 24-105 sitting around?

Sep 20, 2008 at 03:14 AM

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p.4 #17 · 5DmkII less sharp than 5D!

Cableaddict wrote:
Even a Sears lens will be resolved at 21 mp. Lenses do not have megapixel limits.

Sure - but that's not really the point. The point is whether those pixels in the corner of the frame look different, i.e. contain more detail, and how much more, than an uprezzed 12 megapixel file. Lenses really do have megapixel limits, in the sense that at any point in the image circle there is a pixel density above which no advantage would be seen. Let's call it the critical density. The critical density is typically higher on the lens axis and decreases somewhat with distance from the axis. If you integrate those critical densities over the area of the sensor, you will get a number of pixels. So a lens really does have a megapixel limit at each aperture, and subject distance, and frequency of light.

In reality, sensors do not have variable pitch, so one often sees optimal detail distinction in the middle of the sensor, but lack of sharpness in the corners. I am sure I don't need to provide an example of that - we've all seen it. Within a certain distance from the center, it is often not possible to tell which part of the sensor you are in, because the lens sharpness exceeds the threshold set by the sensor. But once you are outside that circle, you can measure to what extent the lens falls short of the sensor's maximum resolution, and therefore determine your distance from the centre, based on the known lens characteristics. Some lenses don't even provide optimal sharpness in the centre.

So the question is, for any given subject, what sensor resolution, in megapixels does this image look like. Sometimes a 21 megapixel sensor produces an image which looks like an 18 megapixel image in the middle, and a 14 megapixel image towards the corners. On average, i.e. integrating the apparent resolution over the frame, it might have a total detail resolution equivalent to 16 megapixels. Of course this is all a gross over-simplification, but it serves as a good mental model for understanding what is going on, and why some lenses, at some aperture, seem fine on an 8 megapixel sensor, but disappointing on a 21 megapixel sensor whereas others seem to put detail in all those pixels with ease.

Sep 20, 2008 at 04:01 AM

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p.4 #18 · 5DmkII less sharp than 5D!

Cableaddict wrote:
Here's an important related question: Let's say, for the sake of argument, that the 5DII's sensor truly is superior in every way to the 5D's sensor. (very likely, though not yet proven.)
You take a detailed shot with the lowly" 24-105L, heck with the Sears 24-300mm, on both cameras, and you do the uprez dance on the 5D image. Then you do a 100% crop on each. Forgetting the 14-bit thing for a moment, are you claiming that the 21 mp image will look no better?

I don't think the OP is saying that at all. He IS saying that the detail in the 21 Mp image might not look as crisp as the detail in the 12.8 Mp image if each is viewed at 100% with no resizing. That's the trap that some people will fall into.

If we look at the same area of the scene (e.g. by uprezzing the 12.8 Mp image to 21 Mp and then looking at the same area at 100%) yes the 5DmkII image should show more detail. How much more is the important point. It's likely that we'll have hit the limit of the lens' resolving power before we hit the limit of the extra pixels. But whether this actually happens will depend on the particular lens used.

As has been pointed out, this can easily be tested using a 1DsIII and comparing with a 5D and the same lens. Unfortunately I don't have a 1DsIII lying around to do the demonstration myself: surely someone here does.

Sep 20, 2008 at 04:11 AM

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p.4 #19 · 5DmkII less sharp than 5D!

Thanks David - that's exactly it. 'Trap' is the right word. 5D2 100% crops will have the capability of looking less detailed than 5D 100% crops while actually being more detailed in print.

I don't have a 24-105 so I can't tell you about 1Ds3 results with that particular lens.

What I can tell you is that most of your 5D2 frame is going to deliver significantly sharper results than a 5D with the majority of good Canon lenses in some range of apertures, but at some apertures a lot of the advantage of 21 megapixels will be lost. Also, some lenses will not be able to fully make use of the 21 megapixels towards the corners, at any aperture. You already know that if you have used a 16-35 mk2 on a 5D, since there is no aperture at which the extreme corners are supplied with enough sharpness for the sensor. It will depend on what kind of work you do whether it matters. Landscape shooters may want to use Zeiss 21's and Nikon 14-24's via adaptors. Others will be more easily satisfied and less constricted in aperture and lens choice.

Sep 20, 2008 at 12:00 PM

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p.4 #20 · 5DmkII less sharp than 5D!

brainiac wrote:
It's actually a lot more like comparing a 100 hp car to a 130 hp car, in a 70 mph speed limit zone.

Just because the speed limit is 70 doesn't mean people will drive that slow.

But yes, I do see your point. It's just that as a car enthusiast, I have a little different opinion on speed limits than most.

Sep 20, 2008 at 06:22 PM

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p.4 #21 · 5DmkII less sharp than 5D!

brainiac wrote:

They have singularly failed to notice that if your goal was a 16x20 inch print in very low light requiring iso 12800, then a 1Ds3 will do about as good a job as a D3, and a better job than a 5D. They have failed to see this because they have based their opinion on comparing 100% crops at differing magnifications, as their noise page shows.

Perhaps what needs to be done is to find something of a "standard" large-print size and pixel pitch so that all cameras can be compared at an equivalent relative output. Say, a 16X20 at 300 dpi or 200 dpi. Something that gives a more realistic relative noise capability than simply comparing 100% crops for typical use. I also believe that 100% crops should be compared because people will crop from time to time - my moon shots are always crops since my longest focal length is 1120 mm.

Sep 20, 2008 at 06:31 PM

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p.4 #22 · 5DmkII less sharp than 5D!

ok, i'm a noob at digital [used nikon f1 in 70s for fun]

bought a xti about 7 mo ago and began collecting lenses. now the 50d looks interesting as an upgrade but a friend let me shoot with a 5d and i think that might be a better choice [not shooting fast action sports at this time so 4fps should be adequate]

the real question i have is how do i determine which lenses/apertures could use the 21mp sensor to it's best advantage? tia

Sep 21, 2008 at 11:39 AM

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p.4 #23 · 5DmkII less sharp than 5D!

Tom_W wrote:
brainiac wrote:
It's actually a lot more like comparing a 100 hp car to a 130 hp car, in a 70 mph speed limit zone.

Just because the speed limit is 70 doesn't mean people will drive that slow.

But yes, I do see your point. It's just that as a car enthusiast, I have a little different opinion on speed limits than most.

amen

Sep 21, 2008 at 11:53 AM

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p.4 #24 · 5DmkII less sharp than 5D!

john paskey wrote:

the real question i have is how do i determine which lenses/apertures could use the 21mp sensor to it's best advantage? tia

You are opeining a can of worms there. The perceived wisdom is that the high quality third-party lenses (zeiss etc) are the best quality for wideangle while some of the Canon L range are the best for telephoto.

As for apertures, with almost all optics the middle apertures are *usually* the best compromise between using the edges of the lens at wide open and suffering the effects of diffraction by stopping all the way down, so (roughly) f5.6 to f13 (however it does rather negate the whole point of owning an 85 f1.2 for example)

David

Sep 21, 2008 at 12:43 PM

Lord Fluff
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p.4 #25 · 5DmkII less sharp than 5D!

Think of it another way - the more you increase the Mp on the sensor the smaller the area of lens is being used for each million pixels. If you had a 500Mp sensor and looked at 100% crops vs say a 5D crop, how could your lens possibly be sharp enough to compete?

Sep 21, 2008 at 01:21 PM


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