Daan B wrote:
Even more confusing why they choose to cramp their sensors with more MP's again and again
For a given sensor size and technology, if the overhead percentage remains constant then more pixels will result in improved image detail and less aliasing artifacts; this is true on a per picture basis (assuming reasonably large prints).
jkurkjia wrote:
For a given sensor size and technology, if the overhead percentage remains constant then more pixels will result in improved image detail and less aliasing artifacts; this is true on a per picture basis (assuming reasonably large prints).
Joe, I know
What is worrying me is the pattern/banding noise (at lower ISO's) in cameras like the 5D2 and 50D. I sincerely hope Canon got it right with the 7D sensor. But until I have seen and developed some 7D RAW files, I will remain somewhat sceptic. 18MP's on a 1.6x crop sensor is a lot.
Fred Relaix wrote:
In fact I feel the 7D is really designed to compete with the D400s rather than the D300s. Any MP-upgraded D300s would look like old news now.
Agree.
The 7D will have a longer update cycle for sure. It won't get updated every 12-18 months like the xxD series, so by putting 18mp into the 7D Canon wanted to make it 'future proof', IMO.
This way it can stay on the market for 2-3 years without looking outdated.
Megapixels are such a polarizing topic.
The fact is, detail gives photos depth and 'dimensionality'.
So, on one hand, adding extra megapixels does improve image quality.
Noise suffers, of course, hence the anti-MP sentiment.
But here’s the thing – despite the anti-MP sentiment, the 5DII is a hot selling product and seems to outsell the cheaper and yet better spec’d Nikon D700.
So, it would seem that people like megapixels after all.
ejmartin wrote:
When I tried doing a similar analysis using the ISO 100 image, I noticed that the std devs for the two green subarrays of the RAW could differ wildly (tens of percent) for the same patch. I'm not sure I trust the results at the moment.
Agree.
Happy to see you here, btw
I find the same wild difference in Std.dev for the two green subarrays at low ISO. The relative difference diminishes at higher ISO's.
Using a white wall for the mean-variance method introduces the risk of getting real image texture into the Std.dev. To get the best possible results, we need to balance image texture against read noise. I ran some calculations for the 50D and found the optimal ISO here to be 1600.
The real system gain for the 50D at IS100 is 2.2 (clarkvision)
The results for system gain normalized to ISO 100, estimated with IR images taken at various ISO's for the 50D:
100: 1.43
200: 1.74
400: 1.95
800: 2.09
1600: 2.19
3200: 2.15
6400: 2.05
At ISO1600, the contributions from image texture and read noise are both so low that the estimate is very good, 2.19 vs. 2.2
The similar table for the 7D is (one green channel):
100: 1.02
200: 1.15
400: 1.32
800: 1.65
1600: 2.00
3200: 2.63
6400: 2.70
12800: 2.56
I would expect more contribution from image texture with this higher resolution camera, and thus worse results at low ISO, but I am not confident that the read noise is so low that ISO 6400 is optimal here. Since these images were taken with High ISO NR OFF, there shouldn't be any "cooking" of the raw files in camera either.
The numbers will have to be anchored to an exposure reference before we can tell to what extent they reduce noise or increase dynamic headroom at a given ISO. It can mean both.
keithreeder wrote:
So what does this green channel discrepancy imply, guys?
If you look at the new RAW-sharpness sample at IR, while looking very crisp, it also has lots of artifacts (referenced in a DPR thread). Now DPP is known for that, however, if you look at 200% you can easily start seeing the maze-pattern issue which can also mean a sensor issue. I'm not sure if DPP is that bad. I think a few 5D2 copies had it and they got a new sensor. I vaguely seem to recall someone found that perhaps a green channel imbalance caused it Maybe the sample are using is a poorly tuned pre-pro model?
The 7D has an improved gapless pixel design and so should (might?) gather a bit more light than a 50D's sensor (buckets of photon per unit area). But a crop sensor will have nowhere as much area as a modern FF sensor (a 1.6x crop is only 38% the area of FF). So I would estimate an, observed, improvement of 1/3 stop assuming all other things are equal (NR, etc.) Any more that an incremental Hi ISO improvement and you can be sure that Canon would, already, be advertising it aggressively.
Daan B wrote:
Well, actually I do feel a bit shortchanged. That has also something to do with 5D2 prices dropping by 170 euros right after I bought mine
But I can't believe that Canon didn't have all the new 7D technology (AF, metering, etc) available at the time of developing the 5D2.
I do believe that it was mostly marketing what drove them to shortchange the 5D2 on a few key areas (AF). I mean, there was no need to make it a better camera, because the only direct competitors were the Sony a900 (which isn't top notch when it comes to AF too) and D700 (which has a pro-like AF, but misses the pixels of the other two). Now they will give 5D2 users very compelling reasons to buy the 5D3 when it is released (when they upgrade AF and stuff - which they will no doubt do, since by that time the Nikon D700x will surely be released).
I think it has been proven by now that Canon builds its release strategies upon what other manufacturers are doing (especially Nikon and Sony). So, they are playing a catch up game right now... and had no choice other than to release the 7D to counter the D300s, because the 50D failed hugely. Hereby letting go of the strict seperation between the pro and prosumer market. An old and arrogant strategy that only favors Canon's bank account, but not the demands/wishes of the people who actually use and buy their stuff.
So, in a way I feel shortchanged that Canon didn't give the 5D2 all the new tech (especially in the light of the 7D's release), but on the other hand I am glad that they finally (under pressure) gave up their old dividing ways... and -maybe- got rid off the infamous pattern noise too (but that is a different story) ...Show more →
Sorry you feel short changed, but it's easy to understand; Canon "boned" everyone for the second time with the 5d2. I'm sure that if the economy didn't tank, the 5d2 would be selling for $1995 (US) which is where it always belonged.IMO (or perhaps lower with the new Sony out)..
The 5 series is simply a FF sensor in an xxd body. The original 5d (a FF sensor in a 30d body) was $1,000 over priced when released and the 5d2 is at least $700 over priced today. In digital, the 5 series combines second tier parts/features stacked on top of a great sensor in the 5d and a pretty-good/OK sensor in the 5d2.
The 7d is probably 2007-2008 sensor technology on top of similar body technology (probably no 2009 technology in it). I'm pretty sure that the AF has been around for a while and could possibly have been used on the 5d2 (an educated guess) but since Canon screwed the pooch on the mark 3 series AF, I think they decided to hold back a while and see what happened.
I'm not a candidate for the 7d, but I sure hope it turns out to be a good camera.
PhotogDave wrote:
So now, lets see a 5D2 update with the new AF/Metering etc. I really hope the 1D4 doesnt have more than 12-14MP's...in fear that packing them in will really hender the potential of extreme clean High ISO.
PhotogDave wrote:
This would have been a complete homerun had Canon went with say a 12MP sensor >with this new sensor tech, then we'd be talkin real ISO performance.
keithreeder wrote:
Bear in mind too that - according to DxO - the 5D only weighs in at 11.1, and yet they reckon the Nikon D200 has 11.5, which is more than the 11.3 of the 40D, the camera decribed by DPR in the following terms:
Bear in mind that DPR and DxO compare images both as 100% crops AND as images correctly resized to the same magnification, so it is not surprising that they can't even agree with themselves. Their methods are broken and, and their results inconsistent. They create extra work for themselves by trying to fit together pieces from two different jigsaw puzzles. They both need to read and understand this: http://cyberphotographer.com/megapixelmyth
thw2 wrote:
Looks like Canon is now falling behind Nikon's sensor technology. Not as bad as the pre-D3/D300 era when Nikon was trailing far behind Canon, but certainly VERY disappointing especially after Canon's claim that they aim to improve dynamic range and high ISO performance.
That's one way of looking at it. Another is that this is an excellent 18 Mpixel sensor with superb high iso and a great price, and arguably Nikon has no competitor for it. I agree that DR matters a lot, but the success of the point+shoot market shows that many camera buyers and users don't care about it, and are not asking camera shop assistants which camera has the highest DR.
Daan B wrote:
Agreed on that the Nikon/Sony relation might be more complex. OTOH Canon can't just what it wants either, because they have to take the risk involved in developing something new themselves. They also have to sell enough units to break even or make a profit. But at least they can do the development themselves. Even more confusing why they choose to cramp their sensors with more MP's again and again, while IQ remains the same or becomes even worse (pattern noise/banding issues). Which leads me to believe that Canon sensor strategy is more marketing driven than Nikon's... at least when it comes to MP count....Show more →
Briefly, there is not a shred of evidence in the market over the last ten years that limiting the number of megapixels provides better quality images. That theory is in direct contradiction of the only evidence there is, namely that image quality has improved dramatically alongside increases in pixel density, from each and every manufacturer.
Daan B wrote:
What is worrying me is the pattern/banding noise (at lower ISO's) in cameras like the 5D2 and 50D.
This problem is dramatically attenuated in first the 500D, and now the 7D. Results from those cameras do not suffer from banding in the same way that the 5D2 and 50D do. And the 500D and 7D each has more pixels, not fewer, than its predecessor. Onward and upward.
jorkata wrote:
Megapixels are such a polarizing topic.
The fact is, detail gives photos depth and 'dimensionality'.
So, on one hand, adding extra megapixels does improve image quality.
Noise suffers, of course, hence the anti-MP sentiment.
No - there is no evidence that noise suffers, and in fact there is a wealth of evidence to the contrary. The anti-MP sentiment arises simply because people do not understand how 100% crops produce different magnifications. Please read this: http://cyberphotographer.com/megapixelmyth
But here’s the thing – despite the anti-MP sentiment, the 5DII is a hot selling product and seems to outsell the cheaper and yet better spec’d Nikon D700. So, it would seem that people like megapixels after all.
The 5D2 is yet more evidence that pixel density and high iso noise are not related. It is Canon's best ever low-light camera and it is also Canon's joint highest resolving full-frame camera.
Briefly, there is not a shred of evidence in the market over the last ten years that limiting the number of megapixels provides better quality images. That theory is in direct contradiction of the only evidence there is, namely that image quality has improved dramatically alongside increases in pixel density, from each and every manufacturer.
1) I haven't seen the dramatically improved IQ alongside increases in MP's. If you compare output sizes the differences are minimal (if there are any at all).
2) In the meantime, we all have to upgrade our memory capacity and PC power to handle those large files.
3) And things like banding and pattern noise weren't totally eliminated (which affect IQ negatively). Well, maybe Canon has finally got it right with the 7D?
jamesf99 wrote:
The 5 series is simply a FF sensor in an xxd body. The original 5d (a FF sensor in a 30d body) was $1,000 over priced when released and the 5d2 is at least $700 over priced today.
People buy 'em.
In digital, the 5 series combines second tier parts/features stacked on top of a great sensor in the 5d and a pretty-good/OK sensor in the 5d2.
Having used 5D, 1Ds3 and 5D2 extensively for real work in a wide range of conditions, I am curious why you think the 5D sensor is 'great' while the 1Ds3/5D2 sensor is only 'pretty-good/OK'. My experience is that the 1Ds3/5D2 sensor is waaay better than the 5D sensor. Perhaps you have been comparing 100% crops, in which case, please read this: http://cyberphotographer.com/megapixelmyth
Maybe the sample are using is a poorly tuned pre-pro model?
