The Physics of Digital Cameras

[WazzoTheMartian]

Think you understand the theoretical basis for Digital Cameras? ...
Unless you are on the R&D staff for some major manufacturer I very much doubt it.

I set about trying to figure it all out late last year and it has certainly been a surprising journey. Check out my journey through photon flux, Poisson aliasing and hardware limitations. I'll bet at least some of it will raise your eyebrows.

I don't think you'll find this stuff anywhere else on the net, no doubt the big companies know it all but they keep their secrets to themselves.

http://warrenmars.com/photography/technical/resolution/photons.htm

[ATJ]

Interesting stuff, Warren.

They travel VERY fast: 300,000 km/s

You may want to mention that this is (approximately) the speed in a vacuum and that their effective speed is slower in various media (air, water, glass). This is an important property of light/photons in photography (and other fields) as lenses would not work if it were not so.

[phillipb]

I understood the first sentence perfectly.
Therefore there was no more need for me to read any further.
Thank god I don't need to know that stuff to press the shutter button.

[photomarcs]

I understood the first sentence perfectly.
Therefore there was no more need for me to read any further.
Thank god I don't need to know that stuff to press the shutter button.

 LOL Amen to that, Good read nevertheless =D

Though, as Aim54x has pointed out somewhere before, his views on the Fuji CCD EXR is rather disturbing, seems quite heavily false and misleading..

[aim54x]

Though, as Aim54x has pointed out somewhere before, his views on the Fuji CCD EXR is rather disturbing, seems quite heavily false and misleading..

Now that you have let it out of the bag Marcus (such a good friend you are), I have only really had a read through the article (primarily the later pages) and was quite disturbed by some of the things said. Esp in reference to Fuji (does the author have a dislike??)

without making a special mention of Fuji: It is my assessment that Fuji make a living in the hyper-competitive world of digicams by making cheap, 2nd rate products, then use some gimmick to misrepresent them as class-leading and charge accordingly, but leaving a margin so that their price seems a bargain. They love to talk up their "Super CCD" technology which uses a diamond pattern instead of a square and has piss-farting little extra sensors at the corners. Supposedly this is supposed to give amazing improvements in sensitivity... This is a lie. As I have shown in the course of this analysis the only thing that matters is pixel pitch. Little corner sensors aren't going to do Jack Shit and the wasted space means that the end result is actually LESS sensitive not more. If you need proof just use one of their crap products and look at the horrible NR-smeared results for yourself. Their latest trick is their "EXR" technology, which is just pixel binning in camera. You can do pixel binning on your computer simply by resizing in your favourite editor. "Get Fucked Fuji!" You are the snake oil merchants of the digital camera world.

I find it hard to believe that someone that has spent so much time in "reading" about the physics behind a digital camera can fail to read the data about the Fuji SuperCCD and SuperCCD EXR sensors that he has such a disagreement with. The whole crux of the SuperCCD technology lies in its "OCTAGONAL" photosites which minimise the wasted space between the pixels (and the definition of pixel pitch is actually the distance between two adjacent pixels, not the diameter of an individual pixel, so it does not take in to account the wasted space between pixels - the terms photosite and pixel being used as the same in most of the literature), pixel pitch is increased marginally, but the total working photosensitive area on the surface of the sensor is increased. Furthermore, the extra square photosites in the traditional SuperCCD functioned to add extra contrast information to aid with dynamic range (theoretically).

The modern SuperCCD EXR does not have these extra square photosites, but has a octagonal photosites that are aligned in the traditional SuperCCD 45 deg angle (as opposed to the 90 deg alignment in every other sensor) to minimise space wastage. Furthermore the EXR sensor has a different colour dye system with adjacent pairs of photosites being sensitive to the same colour (ie RRBBRRBBRRBB...then the next line being GGGGGGGG) so adjacent photosites can be binned (pixel binning) on a sensor level to increase effective pixel size (ie make each pair of pixels act like a single larger pixel) which according to the physics says we get better low light performance and dynamic range (larger pixel pitch, fewer megapixels). The EXR sensor is the only sensor that has this ability to pixel bin at this level, and has the added advantage of not producing false colours whilst doing so. Just a trivial note on the EXR sensor, pixel binning is only one of its tricks, the other very interesting trick is the ability to shoot two differential exposure frames to combine increasing dynamic range similar to the way a HDR bracket does so (think a 2 shot HDR bracket in camera). Having used an EXR camera and numerous SuperCCD cameras I have to admit that the tech does what it claims to.

I really feel that, although this article does contain a lot of useful information it is written the latter stages (especially) of it is written in a manner that distorts the truth with little use of proof. The author appears to be attempting an emulation of the style of writing that has gained a mr Rockwell both an audience of adoring fans and people that cannot help but laugh at the inaccuracies.

Did anyone note the string of Wiki references? Surely if you have spent time to research this topic you would have the sense to realise that WIki is not an acceptable reference for anything that is to carry scientific weight. It is too easy to publish inaccurate information, flawed arguments, biased opinions and plain bad research on the web, this is yet another example.

[Greg B]

Strange first post Wazzo.

[ATJ]

We shouldn't feel honoured...

http://www.digitalslr.com.au/forum/view ... c075b1777e
http://luminous-landscape.com/forum/ind ... opic=40213
http://74.125.95.132/search?q=cache:FGE ... =firefox-a

[aim54x]

We shouldn't feel honoured...

http://www.digitalslr.com.au/forum/view ... c075b1777e
http://luminous-landscape.com/forum/ind ... opic=40213
http://74.125.95.132/search?q=cache:FGE ... =firefox-a

I thought as much....esp after reading the article....someone wants to emulate Ken...

[surenj]

Strange first post indeed.

What are the authors real intentions?

[WazzoTheMartian]

Yes I have posted the same link in 2 other photographic forums. There is nothing untoward in this. I wish to give lots of people the chance to read this interesting information. Not everybody reads DSLRUsers.

Strange that no one has commented on Poisson aliasing, which is the central issue and the issue that makes my analysis unique (as far as I know).

As far as being compared to Ken Rockwell goes: Yes I have read his site from time to time and I think it is worthwhile and I agree with SOME of what he has to say. Stylistically however I think we are quite different; I base my conclusions on maths and physics whilst he makes his judgements purely on the pictures he takes.

As for AIM54x: There is one born every minute and it is people like you that keep Fuji in business.

[surenj]

As for AIM54x: There is one born every minute and it is people like you that keep Fuji in business.

Wazzo, I wouldn't be insulting a highly regarded senior member of this forum especially since you are a new member. Also it would not be tactful since you want people to read your paper. I for one, would be put off reading it when the author seems to have this aggressive attitude.

[gstark]

As for AIM54x: There is one born every minute and it is people like you that keep Fuji in business.

Wazzo,

Please take a few moments to read our FAQ. Flaming and personal attacks of any type are not permitted at any time within this forum. This sort of remark is not acceptable here, and I would respectfully suggest that you need to consider your words more carefully in future.

[aim54x]

Strange that no one has commented on Poisson aliasing, which is the central issue and the issue that makes my analysis unique (as far as I know).

As far as being compared to Ken Rockwell goes: Yes I have read his site from time to time and I think it is worthwhile and I agree with SOME of what he has to say. Stylistically however I think we are quite different; I base my conclusions on maths and physics whilst he makes his judgements purely on the pictures he takes.

There is nothing worth commenting on here other than the complete and utter lack of direct referencing to ANY documentation in which you reference the workings for the "physics and maths" that you use to make your conclusions. It is easy to use numbers to write an explanation that makes sense, especially on a little known subject matter (in which you claim your work is), so unless you wish to provide references to the documentation from which you have gleaned these explanations then there is little use claiming explanation, this is the system of peer review, in which any scientific writing has to be pass, so as you claim to be providing an explanation based upon "maths and physics" (both of which are science) then it is fair that you write to the rigors of scientific writing. Your sensationalist writing style with regular embelishment and strong, UNFOUNDED opinion harks back to the style of Mr Rockwell that you so claim to be different to. Without proper reference, nor critical argument, your writing falls to the level of Rockwell, but at least he provides constant streams of images and openly admits that his writing is humourous, whereas you have claimed proof.

As for AIM54x: There is one born every minute and it is people like you that keep Fuji in business.

As someone who has spent a lot of time talking with the technical department of Fujifilm, someone who owns and uses a number of SuperCCD cameras and someone who has sought to understand the technology for what it is, I am offended that you have grouped myself as someone that keeps Fuji in business, someone who is completey sold on the marketing. On the other hand you are someone who has researched purely on the internet (or so it seems) have not encountered a Fuji (you have only used a Canon A610, Canon EOS 400D and a Nikon D60 as far as I see) I find it hard to swallow that someone that has no apparent experience with a Fuji (esp one with a SuperCCD sensor) can make such a claim (with incorrect information) yet still decide to make such a remark. PS: for those interested, It may be a FUJIFILM link but have a look at:
http://www.fujifilm.com/products/digital_cameras/exr/

It explains the SuperCCD and SuperCCD EXR sensors in an easy to digest form and clearly shows that the photosites are not 'diamonds', nor waste available sensor area.

[gstark]

Think you understand the theoretical basis for Digital Cameras? ...

Ok, I'm involved in making photos. I understand photography, and the basics of how a digital camera works.

Just as, in order to drive a car competently, there are many things that I need to know and understand, but neither the finer points of the Otto combustion engine, not of how a differential works, are necessary for me to achieve that goal.

What specifically is the purpose of your post? In a practical sense, how will this help our membership base improve their photography?

I know that too often we focus on the minutae, ignoring or avoiding the big picture, but instead we pixel peep, when that has no real or practical bearing upon the images that we produce.

I suspect that you may be going down that path, but I would appreciate your further comments to describe how this information may be of a more real and practical benefit rather than .. just going out and making some photos.

[photomarcs]

Not everybody reads DSLRUsers.

well they should.

As for AIM54x: There is one born every minute and it is people like you that keep Fuji in business.

This coming from someone who uses a digital camera. Sorry, but who's the first to develop a 3d imagery camera to reach the market?

and yaeh, they are born every minute, why? most pro labs use a frontier machine combined with Fujifilm crystal archives.. makes sense. Good statement.

oh, and H series hassy's are Fuji designed, and H series lenses are fujinon lenses. And who can afford to use them? Professionals.

So about you being such a knowledgable photographer, i don't deny. Just others tend to know more than you in this instance. Why don't you start learning? or have you given up and settled for your own opinion?