The Future of CCD Sensors

[bcooter]

I buy about 4 drives a year, but then some shoots only involve 20 frames, I am yet to break/replace a shutter.

I wish.

The image I showed is only 1/2 of the originals during that period, but it would be too difficult to do a snap of our downstairs digital suite because they is so much stuff laying around on 4 computer screens that hasn't been cleared.

From August to Dec. of last year we spent slightly over 12  grand on drives and this weekend I'll buy another 3 to 4 thousand to do some backups and organize a recent edit and two projects.


BTW:   It's not bragging it's actually quite shocking to spend more on drives than the cost of a leica.

IMO

BC

[eronald]

The primary difference between CCDs and active pixel CMOS sensors is not where the A/D is done: Canon for example still uses off-board ADC, like all CCD cameras do.

Instead most basic difference is that an active pixel CMOS sensor reads out each photosite by transferring the signal directly to the edge of the sensor, and amplifying it in the process, which helps to reduce the effect of subsequent noise in the analog electronic signal path.  I see no good reason why anyone remains nostalgic for the older, slower, noisier, unamplified approach of a CCD.  In particular, Ronald's idea of a CCD with on-chip ADC might be viable, but it would not address the primary disadvantage of CCD's.

On the other hand, most recent active pixel sensor designs [Sony EXMOR, recent Panasonic 4/3" sensors, the Aptina sensors in Nikon One cameras, the CMOSIS sensor of the newest Leica M, etc.] also then do the ADC on the sensor, and in fact do it with an ADC unit at the end of each column of photosites, and this early ADC seems to help further with noise reduction, by avoiding the need for the analog signal to be transferred along the sensor's edge and beyond.


CCDs might be better suited to small volume products: apparently, once a basic CDD photosite is designed, it is relatively easy to lay out sensors of various shapes and sizes using that photosite design, whereas each different shape and size of active pixel CMOS sensor requires more new design work.

Nothing stops a CCD design from adding an onchip AD at the end of each half line or half column, on chip or off chip.
Existing designs have 4 readouts, I believe.

Edmund

[eronald]

With the CCD cameras I've owned and still use, I see a difference, our crew sees a difference, our retoucher sees a difference, when client's select images from our portfolio about 70% are from CCD images and since more than half of what we show is from cmos cameras, that's interesting.  

I know the assistants see a difference because they all ask to borrow the contax/phase and now the leica and they don't ask unless they really want something.

Though except for certain situations, I'm off the ten billion iso, 600 frames a set squirrel wheel.  

Due to budget and time restraints I got into that but 400 frames of junk is 400 frames of junk.   I'd rather have 20 good options that work.

I'm also off the we'll fix it in post style of working.    That only goes so far and post production should be a part of the beginning creative brief, not a band aid to fix something.

To me CCD cameras work great in post processing.

Whether the look comes from a filter array, the convertor or the sensor I don't really care.   I just know what I see and I see it from the cropped sensor M8 to the p21+, p30+, Aptus 22 and the Leica S2.

In fact I bought the Leica because I knew cmos was coming and I thought I should get in while there was still something left to get.    

A great byproduct of the S2 was how well it handled HMI and even LED lighting.  We do a lot of parallel productions with motion and stills and usually my cmos camera files look washed out and thin with hmi lighting, the ccd has bit and color.

All of the samples I've posted from the S2 were continuous lighting, mostly hmi.



and this is the original crop



This was a one off from the same session with the oly em-1 and it's pretty it worked, but it's a much more fragile file than the Leica and much more difficult to separate colors.


Anyway, we shoot a lot of images, This is 9 months of master raws

and I stopped counting numbers when we crossed the 300 terabyte count.  (which obviously covers a number of years). though I based my opinion ONLY on my experience.  

I don't know or care how other photographers get their results, that's none of my business.

But let me be clear, that doesn't mean I'm right, it just means I'm right for me.   We all work differently, we all have different end agendas and obviously different opinions.

IMO

BC

Actually, I think I'll probably also buy one of the old CCD Pentaxes or a Leica S when the prices have fallen. These two cameras seem usable in practice for an occasional amateur like me; the old prices of Phase were nowhere sustainable, because of the lousy body and because half those backs are actually quite rotten in practice.  It's clear that CMOS is now getting really good, esthetically I'd say the yellow file is the one I like most out of this bunch. But of course the way the scene is set and lit counts for a lot.

Edmund

[bcooter]

Actually, I think I'll probably also buy one of the old CCD Pentaxes or a Leica S when the prices have fallen.

I think your fine with what you have, given what you shoot. 

I don't think your going to see a Lecia S anything or a Pentax 645 drop that much in price.   The people that use medium format generally have no issue lighting a scene or using a tripod.

Also you didn't factor in the price of lenses.

Actually, if I worked only for pleasure i'd buy another M8 or two M9's a few lenses and never look back, because they do about everything I would need for personal work.  For commerce things like tethering come into play.

IMO

BC

[eronald]

I think your fine with what you have, given what you shoot.  

I don't think your going to see a Lecia S anything or a Pentax 645 drop that much in price.   The people that use medium format generally have no issue lighting a scene or using a tripod.

Also you didn't factor in the price of lenses.

Actually, if I worked only for pleasure i'd buy another M8 or two M9's a few lenses and never look back, because they do about everything I would need for personal work.  For commerce things like tethering come into play.

IMO

BC

As you say, I seem to be doing alright with what I use, namely a $1500 1Ds3 that I bought used, about as clapped out as an old yellow cab
There's a bunch of them being sold locally with replaced shutters now, and I'm seriously thinking of picking one out of the bunch that has a good sensor. Mine cannot really do 160O ISO.

I don't know about the 645D which as you say was probably bought by pros who light, or landscape guys who shoot by day, but the Leica S are sure to flood the used market in due course as they were bought by amateurs; it's happening now with the M9s here in Paris, all these guys who bought them as toys are dumping them - if an M9 has scratches it is now unsaleable. BTW, a lot of M9 samples have had their sensors changed, there must have been an issue.

Edmund

[Jim Kasson]

Nothing stops a CCD design from adding an on-chip AD at the end of each half line or half column, on chip or off chip.

In order to do that, the CCD semiconductor process has to allow the construction of the devices required by the circuit design of the ADC. Not always easy. Getting analog devices on mostly-digital CMOS chips was, as I remember, somewhat of a struggle.

Jim

[Telecaster]

Actually, if I worked only for pleasure i'd buy another M8 or two M9's a few lenses and never look back, because they do about everything I would need for personal work. For commerce things like tethering come into play.

I just bought a second M8(.2) and have arranged to sell my A7r, FE lenses & various adapters to a friend-of-a-friend (at close to cost). For me the M8's pleasure factor is off the charts. My favorite M lenses just sing with it too. Unloading the Sony also frees up time & opportunities for using the 645D. Sometimes ya gotta do the wrong thing to find out what the right thing is.   

-Dave-

[eronald]

deleted

[BJL]

Nothing stops a CCD design from adding an onchip AD at the end of each half line or half column, on chip or off chip.
Existing designs have 4 readouts, I believe.

Yes, as I said in my comments that you quoted, your idea of a CCD with on-chip ADC idea might be "viable", but as I also said, earlier ADC is not the main reason that CMOS is stomping over CCD by almost every measure, and was not relevant at all to the way that Canon's CMOS gave it dominance over competing DLSRs when they were still using CCDs. Instead, it is the noise and DR advantage of early on-chip amplification in active pixel sensor designs.

Perhaps you should read my subject line before you reply, so that you do not miss my main point.

[eronald]

Yes, as I said in my comments that you quoted, your idea of a CCD with on-chip ADC idea might be "viable", but as I also said, earlier ADC is not the main reason that CMOS is stomping over CCD by almost every measure, and was not relevant at all to the way that Canon's CMOS gave it dominance over competing DLSRs when they were still using CCDs. Instead, it is the noise and DR advantage of early on-chip amplification in active pixel sensor designs.

Perhaps you should read my subject line before you reply, so that you do not miss my main point.

I'd need to understand your point before I get it.
I'm tired, obstinate, and unconvinced
Let me sleep on this ...

Edmund

[tsjanik]

I just bought a second M8(.2) and have arranged to sell my A7r, FE lenses & various adapters to a friend-of-a-friend (at close to cost). For me the M8's pleasure factor is off the charts. My favorite M lenses just sing with it too. Unloading the Sony also frees up time & opportunities for using the 645D. Sometimes ya gotta do the wrong thing to find out what the right thing is.   

-Dave-

Dave,

As a happy 645D user who has been tempted by the size and weight of the A7r, I'd love to hear why you dumped the Sony.

Tom

[BJL]

I'd need to understand your point before I get it.
I'm tired, obstinate, and unconvinced
Let me sleep on this ...

Just read up on how active pixel CMOS sensors work, and on the read noise and DR measurements for the best ones compared to the best CCDs. Or look at the deep shadows in samples for a quick demo of the far lower noise floor of good CMOS.  The key is the word "active"!

[Telecaster]

As a happy 645D user who has been tempted by the size and weight of the A7r, I'd love to hear why you dumped the Sony.

It's pretty simple: the Sony offers great image quality, not to mention multi-mount adaptability, but in the end it doesn't work that well for the kind of quick reaction "see, frame, click" approach to photography I enjoy most. With a filled-out native lens lineup it might be a partially different story...but that's in the future (if ever). I've loved rangefinders since I was a teenager but had forgotten in my long layoff from enthusiastic pic-taking (nerve compression issues, now resolved) just how much RF cameras suit that approach. And I guess I got sidetracked by D-SLRs in the 2000s too.

The 645D is definitely big & heavy compared to an M8 or A7r. But it suits the other kind of pic-taking I enjoy...the slow & considered kind. I owned & used a 645Nii for awhile pre-digital for the same reason. I could do this with the Sony—I certainly have a flexible enough lens lineup (via adapters)—but the 4:3 aspect ratio suits me better for careful composition and using the 645D & its lenses is a pleasure. I do reserve the right to change my mind re. usability when I get older & creakier.   

-Dave-

[sbernthal]

With the CCD cameras I've owned and still use, I see a difference, our crew sees a difference, our retoucher sees a difference, when client's select images from our portfolio about 70% are from CCD images and since more than half of what we show is from cmos cameras, that's interesting.  

You guys keep going around and around and getting nowhere.

I think we can all agree that when we give the client images from a Leaf back and a Canon DSLR, they will choose the Leaf images most of the time. That is true also based on my experience.
However, that does not tell us whether CCD gives a better picture than CMOS.
There is a lot more hardware, firmware and software that go into making the final image.
The difference could be the sensor technology, but it is also very possible the difference is in the secret sauce (all the rest of it).

Making endless theoretical discussions about engineering aspects, is also without merit IMO.
Let alone the fact that only a few can properly understand it, having an online discussion without properly defined criteria and boundaries as in formal research, will not produce credible results.

What we need is a very simple thing - compared images from IQ250 and IQ260 - from the same company, hopefully made with similar "secret sauce".
These images need to be taken with no stress - no pushing, no long exposure, no lighting from a window, no high ISO - they need to be properly lit studio images with parameters like 1/125, f/16, ISO 35/100. No crops or any post processing - just straight jpgs are fine.

I don't think Phase commitment to quality is fake. If they chose to release a CMOS based back, then my best guess is that it is capable of producing at least same quality results as their latest CCD based backs.

I wish one of the dealers would release such photos so that we would know for sure.
When I wanted to buy a back, one of these dealers (who shall remain nameless), took about 5 minutes to send me the exact type of image that I wanted to see... And it worked for him too.

[torger]

There is an engineering explanation already: the secret is in the CFA optimisation for colour or for ISO. Almost all dslr CMOS have been optimised to provide great iso, but not the IQ250 which is optimised for colour, even Phase One has said it themselves.

So I would not worry.

Leica has not been using state of the art sensors, so it's not surprising that they have had issues with quality. I would not take their CMOS issues as a sign that there's a specific problem with CMOS on the whole.

[Jim Kasson]

There is an engineering explanation already: the secret is in the CFA optimisation for colour or for ISO. Almost all dslr CMOS have been optimised to provide great iso, but not the IQ250 which is optimised for colour, even Phase One has said it themselves.

Are you saying that, in the IQ250, Phase One is using a different CFA than the other two manufacturers who are offering products (H5D-50c, 645Z) based on the same chip? Or are you saying that all three manufacturers are using the same CFA, and that it's different from the CFA used on Sony's smaller chips? The fact that the base ISO is the same for all three indicates that the CFAs are the same for all three 33x44mm-sensor cameras wrt ISO/color tradeoffs.

Thanks,

Jim

[Jim Kasson]

Here's a paper on the tradeoff of color accuracy vs color noise in CFA design that bears on the ISO/accuracy issue that torger was talking about.

http://smartcamera.stanford.edu/~brian/papers/pdc/ColorFilterSPIE03.pdf

Jim

[sbernthal]

So you saying that Canon is using CMYG and Phase is using RGGB?

I was sure everybody were using RGGB.

[torger]

Are you saying that, in the IQ250, Phase One is using a different CFA than the other two manufacturers who are offering products (H5D-50c, 645Z) based on the same chip? Or are you saying that all three manufacturers are using the same CFA, and that it's different from the CFA used on Sony's smaller chips? The fact that the base ISO is the same for all three indicates that the CFAs are the same for all three 33x44mm-sensor cameras wrt ISO/color tradeoffs.

Thanks,

Jim

I don't know. My guess is that they're the same, but individual customization has been made before. CFA is applied as a separate step so you can provide different types for the same sensor if you like.

[BJL]

sbernthal,
I agree with almost everything you say, but for the sake of comparing the current state of the art in large CCDs to active pixel CMOS sensors, I would like to see a slightly different test, equalizing as many other factors as possible, including lens, format size and brand, in case different camera makers adopt different approaches to color handling.  So I would like to see the same (Phase One) body set up in the same location and used with an IQ250 and also with either an IQ260 or better yet an IQ280, with the same lens -- and the images from the larger sensors cropped to the same FOV as given by the smaller IQ250, so that the same portion of the image from the same lens is being used to photograph the same composition.

It might help to also roughly equalize pixel size (and thus pixel count with this scenario), in which case the IQ280 is best: its pixel size is almost the same as that of the IQ250 (5.2 vs 5.3 microns).