DPR Forum

Welcome to the Friendly Aisles!
DPRF is a photography forum with people from all over the world freely sharing their knowledge and love of photography. Everybody is welcome, from beginners to the experienced professional. Whether it is Medium Format, fullframe, APS-C, MFT or smaller formats. Digital or film. DPRF is a forum for everybody and for every format.
Enjoy this modern, easy to use software. Look also at our Reviews & Gallery!

Regarding Contax N digital and Leica digital back

loom

Active Member
Hi everyone,

I talked with the friend of mine who works in San Jose after the digiback for Leica R8 was announced, and once again he gave me very useful comments, which is as follows:

-----------------------------------------------
The CCD N digital incorporated, the 3020 has a pixel size around 12um. The true size is around 11um. Canon's 1Ds is 8.8um. Since it's a CMOS sensor, the real size is probably a little smaller than 6um. See the difference here? The 3020 has a much higher dynamic range on colors.
Not even mention the CMOS sensor has a smaller
dynamic range in nature already, for the same pixel size.

So the comparison of ND vs 1Ds on Contaxinfo is basically a comparsion about color resolution v.s.pixel resolution.

Another good thing about ND is the special anti-aliasing/ low pass filter Kyocera developed for ND. It can preserve high contrast detail better than other digicam's. Some people claim that ND has done too much sharpening so its photos look so contrasy... haha... a big no no. It is really the anti-aliasing filter which does the job!

As I had told you before, the problem with the Philips sensor is that it can eat up lots of power and can get hot quickly. It is a full size 35mm sesnor but in reality, it is only good for digiback to use. ND is basically a scaled down 120 camera plus a digiback. You need to have a different mentality when you use it. You can not just use it like using a D100 or a 10D, keep firing away wherever you you go. If you expect it
to perform like a D100 or a 10D, surely you will be disappointed. On the other side, if you use it
in studio only or you can control the lightling
preceisely, take your time to take every picture,
ND will give you great result... the nice color gradaution,good contrast, and great shadow details. As for noises, you can alwas use software to remove them.

Many people have incorrect perception on raw files. They all think the raw files are the image data dumped directly from the CCD/CMOS sensor. The reality is that there are lots of things needed to be done from the analog signal in the sensor to the digital raw data. Every company has its own way of creating the raw image data. The raw data clwu played with first is actually the CCD test data which will be used as calibration data in the image processor to generate the real useful raw file. On the other side, even the signals dumped from those Canon CMOS sensors have already been processed by the on-chip circuits, they are not *raw* anymore.
In other words, raw image files are not as raw as the words seem. Most of them have been heavily processed. What you can do with those raw data is actually very limited. If you think just by adjusting the color curves....etc and you will get something like Zeiss color, this is a big joke. If you really think you can play magic with raw data file, how about this? Take a portrait picture of a lady with both D60 and 10D(both use exactly the same CMOS sensor)at ISO400, and show me that you can adjust the raw files to make them look exactly the same? Since ND and Phase One's digiback are using the same sensor, too, how about show me that you can make ND's photos look as good as Phase Ones?

The key point is that, the better the digicam is,
the more import the lens performance it will be.
If you can not see this point, probably you will
be able to tell the difference between a Nikon lens and a Contax CY lens anyway.

There are lots of things about a lens... the flare control, the bokeh, the shadow detail,
the color gradation... they will all show on
good sensors. The difference is there, just some
people refuse to admit this.

Oh, the N mount is still the best platform for DSLR among all 135 systems. Now the real problem
is Kyocera has to find a good sensor for it.CMOS sensor is really not a solution.

As for the Leica digiback. It is a good move but pretty much it's just an Imacon product. There is no reason that Imacon can not do the same for Contax... the issue is the price. Also, the 6.8um sensor size is too small. This will degrade Leica lenses' advantages on tonality. BTW, you know you can pay around US$12K to modify a RTS3 to a DSLR?
----------------------------------------------
 
> I talked with the friend of mine who works in San Jose after the > digiback for Leica R8 was announced, and once again he gave me very > useful comments, which is as follows:

I take it this is the same friend who is an "IT Professional"? I'm not sure why that caries any credence to his/her statements and how it relates to the subject of digital photography...as IT has to do with setting up computers and installing software on them, and mainting them, not a thing to do with "technology" in general...but none the less...

> The CCD N digital incorporated, the 3020 has a pixel size around 12um. > The true size is around 11um. Canon's 1Ds is 8.8um. Since it's a CMOS > sensor, the real size is probably a little smaller than 6um. See the > difference here? The 3020 has a much higher dynamic range on colors.

I am not sure what s/he is trying to say here, but dynamic range has not a thing to do with sensor element size. And, the type of sensor has not a thing to do with the sensor element size either.

> Another good thing about ND is the special anti-aliasing/ low pass > filter Kyocera developed for ND.

In reality, it's no better/worse than anyone elses. Fact is, the higher the resolution of the sensor the less of a need for this. What, exactly, is "special" about it?

> As I had told you before, the problem with the Philips sensor is that > it can eat up lots of power and can get hot quickly. It is a full size > 35mm sesnor but in reality, it is only good for digiback to use. ND is > basically a scaled down 120 camera plus a digiback. You need to have a > different mentality when you use it. You can not just use it like > using a D100 or a 10D, keep firing away wherever you you go.

The two are NOT related. The speed the sensor can be fired at is directly related to the ability to read out the data from the sensor, and put it somewhere. That is by architecture, and has nothing to do with power and/or heat.

> Many people have incorrect perception on raw files. They all think the > raw files are the image data dumped directly from the CCD/CMOS sensor. > The reality is that there are lots of things needed to be done from > the analog signal in the sensor to the digital raw data.

The RAW data is the data directly out of the A/D, without any setpoints, tonal curves and/or Bayer pattern processing. That's it, that's raw data, period. The signal from the sensor is just that, an analog signal and is not really "data" at that point, only after the A/D conversion process is it really "data".

> In other words, raw image files are not as raw as the words seem. Most > of them have been heavily processed.

That's not true. Show me one ex&le of that from a major manufacturer.

> What you can do with those raw > data is actually very limited.

In what sense? You can do anything to it your tools allow you to do. In fact, there are aftermarket Bayer pattern processing programs that can do a better job than the ones inherent in the camera, or shipped with the cameras, and the images come out better. Where is the limitation?

> Take a portrait picture of a lady with both D60 > and 10D(both use exactly the same CMOS sensor)at ISO400, and show me > that you can adjust the raw files to make them look exactly the same?

It depends on what you mean by "exactly the same". You can take two pictures with the same camera and they can pretty much not be made "exactly the same", again, depending on what you mean buy "exactly the same". I COULD make them indistinguishable from a standard viewing distance, but can I make them bit for bit the same, probably not...even if taken with the same camera.

> Also, the 6.8um sensor size is > too small. This will degrade Leica lenses' advantages on tonality.

By what premise do you believe that sensor element size has a thing to do with tonality?

Some of his/her statements are sure enough true, most of it simply common knowledge and readily available on the web, but there is quite a bit of it that simply isn't correct. With your "friend" not here on the list, it makes it rather difficult to discuss anything s/he says, and makes her/his comments not part of a conversation, and therefore difficult to address.

Regards,

Austin
 
Hi Austin,

Sorry for a deviated description of the background of the friend I've mentioned. Basically he was the one who brought me into the world of Zeiss indirectly, and he has 10+ years of photography and now currently owns a variety of equipments, including a comprehensive C/Y lineup, Hass and a Nikon F100. He holds a computer science PhD from Stanford and now operates his own company doing computer chip simulation stuff in San Jose. He has a very different background from mine, which is medicine and therefore I am unable to understand 100% what he is actually doing with his profession. Besides from issues regarding digital photography we share our opinions/experiences in film photography and a little bit on computational biology, which I am now working on toward a PhD. Of course he is a much more experience amateur photographer than I am. I've only used G2 with 4 lenses and NX with 70-200 for 4 years so far. I began to ask his opinion in digital photography when I can not stand the result my Canon S30 brings, and others simply followed. In addition, he seems to have good relationship with Kyocera guys and companies developing chips used for digital photography. Not too long ago he told me that Kyocera is now talking with NuCore, a company which developed a one-solution noice-reduction chip to do noice reduction at the analog and A/D level, which was once only can be incorporated in medium format digibacks, which allow more room in designs. Panasonic, from his telling, has already decided to use NuCore's chip.

http://www.nucoretech.com/nu2/20_products/ipt/ndx-1260/00.html

Basically he wrote the letter in a relaxed state and some of the arguments might need refinement. Most of the letter started from a post in a Taiwanese website stating that in digital era there will be no differences if you use different lenses, since it is all the CCD and post-processing that make the difference.

Regarding the RAW, from my understanding is that the A/D process itself has already incorporated much processing. It is not that "raw" as you and me had imaging. Of course you can obtain different results using different tools, just as he personally hightly recommends a noise-reduction software. His point was simply that by playing with image processing software you cannot make the images from different lenses look identical. I am actually one of his believer, since however hard I play with the images from my Canon S30 I cannot get something similar to TVSD, not to mention the images I scanned from the slides taken from G2. I know the aformentioned comparison might not be a fair one, but I am simply saying that the lenses do make difference.

Regarding the sensor size, in my two cents is that the smaller the sensor size, the less light a sensor would receive, and that would affect tonality. I might be wrong, since I am not an expert, but I am for sure that the sensor size itself play an important roll in image quality.

English is not at all the native tongue for him and for me, and sorry if I had made any wrong statements or description.

Best, Shu-Hsien
 
Hi Shu-Hsien,

Thanks for his background, but still, that, IMO, doesn't carry much weight as someone who has actually designed. There are a LOT of armchair digital experts out there, and unfortunately, they all have very strong opinions...some right and some completely wrong, so every statement these "experts" make can simply confuse matters more equally as much as they may clarify things.

> in digital era there will be > no differences if you use different lenses, since it is all the CCD > and post-processing that make the difference.

That, to a large degree is absolutely true...until recently, when the sensor pitch (size of the physical sensing elements) has now reached a point where optics does matter.

> Regarding the RAW, from my understanding is that the A/D process > itself has already incorporated much processing.

Sorry, but that is absolutely incorrect. All the A/D process does is simply convert the voltage (or current in some cases) to a number, period. NO processing at all is done, a simple linear (in typical cases) conversion is done. The signal path is quite simple...CCD analog signal to an analog circuit that simply voltage (or current in some cases) matches the range of the CCD output to the range of the A/D input then to the A/D. For ex&le, if the CCD as a voltage output of 0-2.5V, and the A/D has a voltage input requirement of -3 to +3 volts, the analog "front end" will simply apply an offset and then a gain so that it maps 0-2.5V into a range of +-3V (6V peak to peak).

> ...I am simply saying that the lenses do make > difference.

They CAN if the sensor has enough "resolution". On the D-30, no, lenses really didn't make much of a difference. It wasn't until the D-60 that people acknowledged that the better lenses were in fact giving better results.

> Regarding the sensor size, in my two cents is that the smaller the > sensor size, the less light a sensor would receive, and that would > affect tonality.

To a point that would be true, but not at the levels we are talking about here.

> English is not at all the native tongue for him and for me, and sorry > if I had made any wrong statements or description.

Possibly, but I think that he might be missing some understanding as to how a digital camera actually works. Nothing wrong with that, but it is a problem when someone speaks with authority, and doesn't have the story straight. BTW, your English is perfect.

Regards,

Austin
 
Hi Austin,
I have seen you refer to Bayer pattern quite often in your posts but in my ignorance I don't know what this is. Digital is a steep learning curve with which I am struggling and I would much appreciate your explanation.
Thanks,
John
 
> ...I am simply saying that the lenses do make > difference.

They CAN if the sensor has enough "resolution". On the D-30, no, lenses really didn't make much of a difference. It wasn't until the D-60 that people acknowledged that the better lenses were in fact giving better results.

For me this is becoming a very interesting aspect of this discussion. This being the case, can the 'Point and Shoot' Sensor or its equivalents (Sony 1/1.8" CX452 sensor! ) really resolve to a sufficient level, to give the differences that are being perceived by those testing 5MP cameras?

I have done my level best to understand this aspect of Digital photography (nowhere near it yet like many others!); it creates a key decision point; ie is the TVSD really worth the extra money, or would the Konica KD-500 (excellent Hexanon lens from what i can analyse) or Canon S50 do just a good a job of taking the picture that they generally used for? Size, Weight, Print Size, Quality and some of the features IMO remain the key decision points. Many aspects of the final result and print can be tweaked to personality preferences in PS can they not?

What is the difference (absolutes or not) in this final result if derived from a 5MP Point and Shoot and a 5MP DSLR?
 
> What is the difference (absolutes or not) in this final result if > derived from a 5MP Point and Shoot and a 5MP DSLR?

The odds are, a P&S uses what is called an "Interline Sensor", which is far inferior in image quality to a standard "one shot" type of image sensor used in higher end cameras. The way to tell if the camera is using an Interline Sensor is if it has real time preview...which is a property od the Interline sensors and not of the One-Shot sensors. The Interline Sensors are made, primarily (if not initially), for video applications...which is why they don't use a shutter and can provide real-time preview...but these sensors, as I said, give lower image quality.

Regards,

Austin
 
> I have seen you refer to Bayer pattern quite often in your posts but > in my ignorance I don't know what this is. Digital is a steep learning > curve with which I am struggling and I would much appreciate your > explanation.

The Bayer pattern is a pattern of colored filters in the arrangement of Red/Green/Blue/Green, one color over one sensing element. The physical sensing elements themselves (not talking Foveon here) are monochromatic, and in order for them to "see" any color, a color filter has to be used.

Now, the reason for Bayer pattern, is you need the three colors worth of data in order to encompass a large part of the visible color spectrum. No filters, and you get grayscale. But, since you can only have one filter of one color over "a" sensing element, you need this quad pattern to get this range of colors. Two greens are used for contrast BTW. So, in reality, a 6M sensor has %50 of the sensing elements providing Green information, %25 Blue and %25 Red. This leads to a reduce resolution of actual information. This reduction is made up for by a Bayer pattern processing algorithm which interpolates (mathematical interpretation of the values "in between") which fills in the missing values.

Does that give you a reasonable idea?

Regards,

Austin
 
Posted by Austin Franklin on Wednesday, July 02, 2003 - 3:25 pm:

Now, the reason for Bayer pattern, is you need the three colors worth > of data in order to encompass a large part of the visible color > spectrum. No filters, and you get grayscale. But, since you can only > have one filter of one color over "a" sensing element, you need this > quad pattern to get this range of colors. Two greens are used for > contrast BTW. So, in reality, a 6M sensor has %50 of the sensing > elements providing Green information, %25 Blue and %25 Red. This leads > to a reduce resolution of actual information. This reduction is made > up for by a Bayer pattern processing algorithm which interpolates > (mathematical interpretation of the values "in between") which fills > in the missing values.

Hello!

Does it mean that in fact the 5Mpix camera has only ca 1.25 M "full color" pixels???

Regards, Krzysztof Janus
 
I'm sure that the lens makes a difference even with 2 or 3 MP cameras ! I've tested several point-and-shoot (p&s) digis and found the Sony DSC-S70 with the Carl-Zeiss-lens really the best then (some years ago). Much better than a Konica, Fuji or some cheap cams. No sensor can capture what the lens doesn't give him ! That's the point with the better 5 MP-cams : It's stil the optics that makes the difference ! and I love my Olympus E20p even it's quite big but very well built, a real camera not like a toy. A real SLR (not a viewfinder), very fast compared with the p&s and a very good and fast lens. Paul
 
Back
Top