The GetDPI Photography Forum

Great to see you here. Join our insightful photographic forum today and start tapping into a huge wealth of photographic knowledge. Completing our simple registration process will allow you to gain access to exclusive content, add your own topics and posts, share your work and connect with other members through your own private inbox! And don’t forget to say hi!

CMOS Look, CCD Look in MF Sensors

Lobalobo

Member
Although I'm an amateur shooting 4 x 5 film, I have a curiosity about MF sensors, particularly as used on technical cameras. Thus, I've read with great interest the positive reviews on the new Sony CMOS backs, including in the Phase One IQ250. This review, from Digital Transitions, included image comparisons among the IQ250, IQ260, and IQ280:

Phase One IQ250 Tech Cam Testing - DT Blog

What struck me is the different look of the CMOS and CCD sensors (technical results aside). For lack of a better description, the CCD images seemed punchier and the CMOS images flatter, or duller. Yes, I know an amateur should not be judging sophisticated tools such as MF sensors at all, or on a computer screen, and using consumer-minded attributes such as "punch." But there did seem to me a noticeable difference and I wonder whether those more knowledgeable than I am have a view on whether there is an inherently different look to the CMOS images as compared to the CCD images or whether this is just a result of this one test or of the processing selected. Thanks.
 
It's hard to isolate exactly what the reason is, maybe it's a difference you see between the IQ250 and 260, but other implements of the Sony or Kodak or Dalsa sensors have different characteristics, and these too change depending on the software you process them in.

On the whole, I suppose your observation is close to the truth, CCD images tend to look more like the real thing out of the box, while CMOS output is very malleable, especially when it comes to shooting in anything other than ideal conditions.
 

Lobalobo

Member
Thanks. Sorry to have missed earlier threads. Whether it's CMOS or the color profile adopted that contributes to the look is, I guess, an open question. Inasmuch as 35mm (and smaller) CMOS cameras have eliminated complaints by CCD loyalists, I imagine that the same will occur in future generations of MF sensors. That probably means the end of new generations of CCD sensors before long, though, this presupposes that the new CMOS sensors can be produced to permit usable movements against a full-frame 645 sensor despite (what I take it) is a requirement of micro lenses for CMOS (but not CCD).
 

Don Libby

Well-known member
Personally and professionally I too prefer the "look" for lack of a better word of CCD vs CMOS. The closest I ever saw between 35 and MF was the Leica M9 then again it has the same CCD sensor. CMOS to me is the same as 35mm; while a "nice" format I nevertheless like the RAW and finished files from CMOS.

Just my limited opinion....
 

ErikKaffehr

Well-known member
Hi,

I guess that we may mix up some things. The M9 uses a Kodak sensor, like the ones used the Pentax 645D and the older Phase backs. Leaf has been a long time user of DALSA sensors which have a different color reproduction.

Canon cameras use Canon CMOS, with Canon's choice of CFA (Color Filter Array) properties, while Nikon uses mostly Sony sensors probably with CFA specified with Nikon.

Sony uses pretty much the same sensors as Nikon, but probably with different CFA design.

The next step is raw conversion, demosaicing followed by transforming the RGB signals into an internal colour space. Now, an output profile is applied on the internal colour space. That profile can contain "hue twists" and other manipulations. Here is a nice example: ChromaSoft: Visualizing DNG Camera Profiles Part 1

Best regards
Erik


Personally and professionally I too prefer the "look" for lack of a better word of CCD vs CMOS. The closest I ever saw between 35 and MF was the Leica M9 then again it has the same CCD sensor. CMOS to me is the same as 35mm; while a "nice" format I nevertheless like the RAW and finished files from CMOS.

Just my limited opinion....
 

Don Libby

Well-known member
I was still using the older p45 when I had the M9. Not certain how it would compare with the newer IQ sensor.
 

Lobalobo

Member
I guess that we may mix up some things.
So, Erik, is the upshot of your comments that a manufacturer such as Dalsa could produce a CMOS sensor and choose a CFA to replicate what some call the CCD "look"?

Beyond hue, the CCD look, best I can tell, if it has a technical explanation (better than "pop"), is greater micro-contrast. Are CMOS sensors inherently less able to produce micro-contrast than CCD sensors? (My guess is not, inasmuch as the original Canon 5D had the pop, or micro-contrast, favored by those who like MF CCD, and that was a CMOS sensor.) If not, then I suppose the answer to the different looks comes down to manufacturer choice, a good omen for the future, I suppose.
 
Color is something subjective. If you fall in love with the Sony CMOS sensors when it's clearly superior in performance, and get used to the post-processing procedure with it, you just can no longer leave it. In the next few years when it gets succeeded by another technology and you cannot afford to upgrade / keep up-to-dated then you enter a status quo and insist that you prefer the color of the Sony CMOS sensor so that you still have the faith to keep using your gear.
 

Lobalobo

Member
Color is something subjective. If you fall in love with the Sony CMOS sensors when it's clearly superior in performance, and get used to the post-processing procedure with it, you just can no longer leave it. In the next few years when it gets succeeded by another technology and you cannot afford to upgrade / keep up-to-dated then you enter a status quo and insist that you prefer the color of the Sony CMOS sensor so that you still have the faith to keep using your gear.
Fair enough, and I agree entirely that color is subjective. As a hobbyist (who does not shoot products) I am not interested in accuracy as much as a pleasing look (including to skin tones). But what has been discussed here as a "CCD" look, though perhaps inaccurately, is not about color or not about color alone. The CCD library photos (at least the posted jpegs) reveal a greater distinction between objects and hues than do the CMOS photos. Look, e.g., at the pattern in the rug, which jumps out at you in the CCD images, but appears more uniform, duller, in the CMOS. I have no idea whether this is inherent in the CCD versus CMOS technology, which is why I posted the question, but there does appear to be a difference, and more importantly (because I know very little about this) experienced photographers have said the same here.
 

Ken_R

New member
The biggest difference I generally always see with CCD vs CMOS is that with the CMOS almost always the red channel is too saturated and lacks good detail and accuracy. I don't know why that is maybe it is part processing part the sensor but with CCD (IQ160) the reds are generally more accurate and smoother. Color differentiation is also much higher with my IQ160. It is VERY sensitive to even small color adjustments, it seems to pick up every little hint of color in a scene. Why that is? I do not know, and don't really care, I am not a sensor / camera engineer / designer! :D

The discussions in this and other forums are endless on this matter.
 

Lobalobo

Member
Color differentiation is also much higher with my IQ160. It is VERY sensitive to even small color adjustments, it seems to pick up every little hint of color in a scene.
Primarily, this is what I am seeing as well. This was also my view of CCD versus CMOS sensors in smaller formats, though, but CCDs have disappeared from sub MF sensors (except the cheapest ones). My assumption is that this happened because the CMOS images caught up to the CCD in all respects that photographers cared about, including, presumably, sensitivity to color differences (an important attribute, at least to many). If that's so, then perhaps the same will occur in MF. Otherwise, it will be a shame if as technology advances options are lost.
 

carstenw

Active member
I would be surprised if there was a difference between CMOS and CCD which couldn't be equalised by a sensor manufacturer. I suppose that the CMOS advantage at high ISO is partly bought by fiddling with the CFA, just like Canon's colour have gotten thinner and thinner with the years, as they try to improve their high ISO to match the competition, while not making major updates to the underlying technology. I also suppose that the newer tech in the Sony sensor yields an improved DR, which needs to be retained partly by using a much gentler tone curve, and thus yields a "flatter" looking image.
 

Ken_R

New member
I would be surprised if there was a difference between CMOS and CCD which couldn't be equalised by a sensor manufacturer. I suppose that the CMOS advantage at high ISO is partly bought by fiddling with the CFA, just like Canon's colour have gotten thinner and thinner with the years, as they try to improve their high ISO to match the competition, while not making major updates to the underlying technology. I also suppose that the newer tech in the Sony sensor yields an improved DR, which needs to be retained partly by using a much gentler tone curve, and thus yields a "flatter" looking image.

Makes sense.

The IQ160 is optimized for use at base iso (which is where I use it mostly) although it has enough dynamic range that it allows a lot of underexposure (by using higher iso) while still retaining good range and color. It also has sensor plus (pixel binning) which works great but it is unique of PhaseOne and the more recent backs so it is not a solution available in other products.
 

Lobalobo

Member
Makes sense.

The IQ160 is optimized for use at base iso (which is where I use it mostly) although it has enough dynamic range that it allows a lot of underexposure (by using higher iso) while still retaining good range and color. It also has sensor plus (pixel binning) which works great but it is unique of PhaseOne and the more recent backs so it is not a solution available in other products.
Makes sense to me too, that the differences we are all seeing are market, not technology driven: Want a sensor that produces images at high ISO, low noise, lots of dynamic range, and lots of resolution? Pay the price in a somewhat flatter image. If this is right, then something like the current IQ CCD sensors (perhaps continuing with pixel binning technology) will still be produced as technology advances, either using CCDs or using CMOS sensors tuned to be used at low ISO for those who prefer the higher contrast and saturation to low-light capabilities, at least for some of their jobs. That would be a good solution, it seems.
 

Lobalobo

Member
I think CMOS chips are simpler and cheaper to make, so I suppose they will win in the long run.
For cameras that cost more than sports cars cheapest available inputs is not a strategy likely to attract customers, particularly demanding pros (I'd think, though I'm not a pro). If CMOS wins in the long run, it will, I'd imagine (and hope) be on terms that provide options for the look the consumers demand, including the look of current CCD sensors.
 

darr

Well-known member
For cameras that cost more than sports cars cheapest available inputs is not a strategy likely to attract customers, particularly demanding pros (I'd think, though I'm not a pro). If CMOS wins in the long run, it will, I'd imagine (and hope) be on terms that provide options for the look the consumers demand, including the look of current CCD sensors.
You sound like a CCD salesman and you say you currently shoot 4x5 film; are you familiar with digital post processing?

I currently own both CCD and CMOS digital backs and do not see a difference in their 'look'. IMO, since they all start as black and white imaging, then have custom CFAs applied and then go further on through custom post processing, you could say a good photographic artist could give them the 'look', or whatever they want to achieve through the process. Sounds to me you are really trying to up-sell CCDs and I think its all hogwash. :thumbdown:


I think Erik's comment quoting Michael Reichmann and an industry expert says it very well: "More significantly, Michael Reichmann stated that he was told by an MFD back designer that the rendition difference between CCD and CMOS was just a myth." READ it here.

The reality is today you can purchase a new 50 megapixel CMOS back for $15,000 or less with excellent Live View and high ISO performance or purchase the newest and greatest CCD back in upwards of $50,000. When photographers are on a budget or make financial decisions based on needs and not emotion, what do you think the educated photographer will pay? The PhaseOne IQ 250 has the same CMOS sensor and 50 megapixels as the $15,500 Hasselblad CFV-50c, but it costs $35,000. So the value of a 'look' IMO will evaporate when it comes to good business sense.

EDIT: I edited this post because I had a suspicion the OP may be trolling the forum up-selling CCD over CMOS, and my apologies if I am wrong, but the OP's timing could not have happened any quicker than after the CFV-50c hit the market as a win-win for photographers and for Hasselblad.
 
Last edited:
Fair enough, and I agree entirely that color is subjective. As a hobbyist (who does not shoot products) I am not interested in accuracy as much as a pleasing look (including to skin tones). But what has been discussed here as a "CCD" look, though perhaps inaccurately, is not about color or not about color alone. The CCD library photos (at least the posted jpegs) reveal a greater distinction between objects and hues than do the CMOS photos. Look, e.g., at the pattern in the rug, which jumps out at you in the CCD images, but appears more uniform, duller, in the CMOS. I have no idea whether this is inherent in the CCD versus CMOS technology, which is why I posted the question, but there does appear to be a difference, and more importantly (because I know very little about this) experienced photographers have said the same here.
I started learning post-processing with the Nikon D800E (Sony CMOS), so when I switched to the IQ260 (Dalsa CCD) I was very frustrated with the color and the look of the CCD. When I switched to the IQ250 (Sony CMOS) I immediately liked the color and the look.

"Experienced photographers" usually means people who started with a Canon 5D or a Leica M9, which had out-dated dynamic range / SNR and the color / look in that era. In my opinion today's "CMOS vs CCD" is just like yesterday's "CCD vs film", period. If I keep using Sony CMOS sensors for years I will also find it difficult to accept the next generation of technology (e.g. organic sensors, back-illuminated sensors etc) :D
 
I think CMOS chips are simpler and cheaper to make, so I suppose they will win in the long run.
As Leica has shown us with the S 007? even though the only real change was a move to a mature sensor design they've been selling for years now? or the price differential between the Phase, Hassy and Pentax variants on the same sensor?

Let's not be fooled into thinking that just because CMOS technology is somehow easier to manufacture, companies won't take advantage of the fact to improve profit margins. A typical pro DSLR body with sensor and all costs around $3500, or up to $6000 for those with a vertical grip, so Pentax isn't being unreasonable with their offer, a sensor that's 1.8x as large needs a like increase in camera size, and the price scales to reflect that. (Although the 645Z body could in theory support up to a full-size sensor meaning that it's bigger still than it needs to be.
 
Top