astrolucida wrote:
You are right - except that in Canon DSLRs it is 12 bits per pixel at the sensor level.
Thanks for the info. I knew I was wrong.. that is why I was pondering between 8 bit or 16 bit. I knew it is not 8 bit... so i guessed 16 bits... thanks again...
Anyway do you think this is also the reason why you are push the EV when shooting RAW if you are outputting 8 bit color data from a 12 bit orginal?? Was always intrigued why RAW preserves data better when pushing EV as opposed to using curves/levels on a already render 24bit photo.
PhotoCinematic wrote:
Andy,
No offense, but there are folks that actually appreciate my signature and would like to see it. You can ask for those that actually take their time and read my signature for their purpose. Thus you may not be intereted but there are those that like to see my updates on lens that I tested and they would like to know.
Also Andy, there are some of us for some reason we cannot get the line across but it keep giving us short lines and this is the reason why alot of us in here and not myself alone have this type of signature.
Frankly, I think the one who has the biggest appreciation for your signature is yourself...
I suggested it before but got no reply - you already have your gear list in your profile, so a short "See my profile for my wonderful Zeiss lens lineup" would be quite sufficient. But if you need to show off, then you need to show off.
Pondria wrote:
In spite of all the critques, Photodo is still the site that actually tested lenses quantitatively. According to them, EF 200/1.8 is the best lens that they have ever tested including Zeiss and Leica.
I think the reason why you get so much debate over lens quality is that even a very rigorous MTF test does not answer all the questions. The Photodo tests are performed at 10, 20 and 40 lp/mm. Take the 200/1.8:
10 lp/mm : 0.94
20 lp/mm : 0.86
40 lp/mm : 0.71
The 1Ds II has 138 pixels/mm, so could theoretically resolve 70 lp/mm. Thus if you were interested in resolving the finest detail, you would need information beyond that in Photodo's tests. We can see that performance has dropped off a lot at 40 lp/mm, who knows what the 200/1.8 is doing at 70 lp/mm. Also, even the Photodo figures are just averages over the frame and don't tell the whole story even at the chosen lp/mm.
Having said that, from the available information on Photodo, there doesn't seem to be a whole lot of support for Zeiss or Leica glass being so much better, e.g. the Contax Planar T* 85/1.4:
10 lp/mm : 0.92
20 lp/mm : 0.84
40 lp/mm : 0.69
and for a fair comparison, the Canon 85/1.2 L:
10 lp/mm : 0.93
20 lp/mm : 0.84
40 lp/mm : 0.66
So the Canon lens drops off a bit more at 40 lp/mm, but not a huge difference. However if this translates into a greater difference at 70lp/mm, this might cause people to see significant differences in fine detail if they tested the two lenses back to back on a 1Ds II.
Andy Biggs wrote:
At the end of the day, lenses that don't get used are of little or no value to the owner. Get lenses that match your needs, not based on collecting the best quality glass, focal lengths aside.
Andy
andy, you are so right. nail on the head, man! i recently sold my 35L and bought the 24L so that i had the focal length that suits me best most of the time, and therefore would get used. the quality is stellar.
i've just shaken up my bag. 24L, 50 1.4, 70-200 f/2.8 i.s. are my lenses of choice. i'm not a lens hound, if it doesn't get used, i sell it hey, i just bought a 1.4x converter, that's a big deal for me on the long end, as i'm a wide shooter. andy, when i go on one of your safaris, i'll need to rent a 500 or 600 canon prime hehehe
stevei wrote:
I think the reason why you get so much debate over lens quality is that even a very rigorous MTF test does not answer all the questions. The Photodo tests are performed at 10, 20 and 40 lp/mm. Take the 200/1.8:
10 lp/mm : 0.94
20 lp/mm : 0.86
40 lp/mm : 0.71
The 1Ds II has 138 pixels/mm, so could theoretically resolve 70 lp/mm. Thus if you were interested in resolving the finest detail, you would need information beyond that in Photodo's tests. We can see that performance has dropped off a lot at 40 lp/mm, who knows what the 200/1.8 is doing at 70 lp/mm. Also, even the Photodo figures are just averages over the frame and don't tell the whole story even at the chosen lp/mm.
Having said that, from the available information on Photodo, there doesn't seem to be a whole lot of support for Zeiss or Leica glass being so much better, e.g. the Contax Planar T* 85/1.4:
10 lp/mm : 0.92
20 lp/mm : 0.84
40 lp/mm : 0.69
and for a fair comparison, the Canon 85/1.2 L:
10 lp/mm : 0.93
20 lp/mm : 0.84
40 lp/mm : 0.66
So the Canon lens drops off a bit more at 40 lp/mm, but not a huge difference. However if this translates into a greater difference at 70lp/mm, this might cause people to see significant differences in fine detail if they tested the two lenses back to back on a 1Ds II.
That should be a good guide to selecting the best lens for your megapixel monster of a camera. From a brief look it looks likes the 90mm TS-E is the one to get.
This is actually very funny----all these assumptions based on fantasy. First of all, the 1DS II will never be worth 2k in 2-3 years---the high end DSLR's hold their value amazing well--why dont you take about five minutes to do your own evaulation. As far as your Leica goes---stick with it----I call it the Leica disease. It's akin to many other diseases where branding seems to have trumped rationality. Good luck and doe us a favor and keep shooting Leica.
stevei wrote:
... The 1Ds II has 138 pixels/mm, so could theoretically resolve 70 lp/mm. Thus if you were interested in resolving the finest detail, you would need information beyond that in Photodo's tests...
Steve,
This poor guy is just getting into digital, and you just perpetuated the gross misconception about sensor-site density being proportional to its resolving power capability. There have many threads discussing this, and this is one of the primary causes of confusion in understanding imaging resolution by newcomers.
Leica Man,
The resolution of a sensor is far more complex than simply counting the photosites on it and dividing by the physical dimensions. This gives you the photosite density of the sensor, but is not indicative of its actual resolving power capability.
For example, the Canon SD500 is a $600 7MP point-and-shoot compact camera with a linear photosite density of about 427 photosites/mm. As Steve points out correctly, the 1DsII has about 138 photosites/mm. Clearly, the lowly SD500 does not offer 3x the resolving power of a 1DsII. The error is introduced by taking the photosite density and turning it into a resolving power metric by mis-interpreting it in terms of lp/mm.
In short, to determine the resolving power of any digital camera, the entire imaging pipeline must be included in the analysis. Typically, only the engineers / manufacters have this level of information, and consumers must resort to experimental determination (like found on dpreview or other sites).
OK, the bad news is that this imaging pipeline will absolutely destroy the MTF capability of any lens that is put on it. The AA filter is one of the most obvious culprits, but a necessary evil in some ways which I don't have space to digress this note any further. I have found experimentally, that "very good" (e.g., commercially acceptable product photo) results typically require a 40 lp/mm MTF rating of about 0.6 or higher. The really exceptional imaging results can be had when the lens can deliver a 40 lp/mm of 0.7 or higher. The Canon 200/1.8L has an average rating of 0.71 as reported by photodo.com. Many of the newer APO Leica lenses are of this quailty as well, and you can contact Erwin Puts for more technical information.
Edited by dklepacki on Mar 20, 2005 at 09:24 PM GMT
The art museums are full of images captured through earlier lenses inferior to even Canon's least sophisticated modern day lenses.
But, since it appears that LM predicated this thread upon blatant gear snobbery, ("my Leicas and CZ's are superior to your Canon lenses"), the adequacy of any particular lens is besides the point.
In fact this is the most blatant example of gear snobbery that I've ever seen in here.
discreet wrote:
Anyway do you think this is also the reason why you are push the EV when shooting RAW if you are outputting 8 bit color data from a 12 bit orginal?? Was always intrigued why RAW preserves data better when pushing EV as opposed to using curves/levels on a already render 24bit photo.
The final JPEG file (as well the monitors) only have 8 bits per color. With RAW, we have 12 bits, so changing the exposure by +-2 EVs does not lose any precision - if the original exposure was made to use the whole 12 bit range.
I have noticed, in practice, that even "overexposed" images can be salvaged with RAW. But this is based on judging overexposure from the camera LCD histogram (blinking parts). So, it seems that the camera picks the JPEG roughly from the middle 8 bits of the 12 bit raw data, giving 2 bits of extra precision to each end.
Naturally the in-camera contrast setting affects this because it treats the range nonlinearly and hence may map the data differently.
I bougth a new Canon 600/4 L IS and i found it unusable at f/4. In fact my old 300/2.8 non IS with 2x converter was sharper.. Maybe i got a bad copy but i think that at that price it should not be possible to have a bad copy. I believe that the IS system is great for low light photography but i think non IS lenses are sharper when used properly. Also check out this website: http://www.astropix.com/HTML/M_DAP/M11/M11.HTM
FretNoMore wrote:
Frankly, I think the one who has the biggest appreciation for your signature is yourself...
I suggested it before but got no reply - you already have your gear list in your profile, so a short "See my profile for my wonderful Zeiss lens lineup" would be quite sufficient. But if you need to show off, then you need to show off.
Here here I couldn't agree more, his signature is way over the top.
hey, i just bought a 1.4x converter, that's a big deal for me on the long end, as i'm a wide shooter. andy, when i go on one of your safaris, i'll need to rent a 500 or 600 canon prime hehehe