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View Full Version : A good article about sensors




Lovesong
Apr 22, 2008, 01:18 AM
I came across this (http://www.anandtech.com/digitalcameras/showdoc.aspx?i=3290) article today. It's pretty straight forward, and could be useful to a newb, or anyone who is interested why digital cameras are the way they are ( questions like why we have APS sensors, etc.)



-hh
Apr 22, 2008, 09:03 AM
Yes, thanks ... quite an excellent article.

FWIW, I found this statement (on the last page) to be particularly of note:

"These are exactly the same reasons buyers chose film SLRs instead of 110 point and shoots in the 70s, and 80s. Those reasons are just as valid in the DSLR market as they were in film, and maybe even more so. "

Having just gone through my deceased Mother-in-Law's photo collection, I've been just recently reminded as to how mediocre that 110 film was. Granted, with the current popularity of using the web to view images downsized to ~1MP this may not be saying all to much today, but true 8-bit LCD displays and other advancements will cause our expectations to rise too.


As well as this one:

" Pundits are already screaming we are going too far with14MP sensors, but they forget that the smallest 4/3 sensor is still more than nine times greater area than the average compact sensor. There is still a lot of room for growth in resolution."

Quite an interesting point that has been overlooked - - it certainly explains why the ~25MP Sony chip was technically feasible. It would seem that I'm going to have plenty of 'need' for more HD space and the processing power of a Mac Pro in the forseeable future. :D


-hh

ChrisA
Apr 22, 2008, 11:00 AM
Yes the article does explain the basics.

I think however the race will be over in 10 years. Once the DSLR is as good as film the pressure will be off. The best 35mm film images can resolve 80 lines per millimeter. There are few lenses better then this. A 24MP full frame sensor is very close to matching a 35mm film camera. With a full frame camera there is not much reason to have more pixels and good reasons not to have more. Eventually the price will drop to under $1,000 for a 24MP FF DSLR. Give it 10 or 12 years.

I worked with a large CCD on a project years ago. The sensor was square roughly 36mm on a side making it larger than "full frame" and it had 4,000 pixels on a side (16MP) This was about ten yeears ago the bare chips with no eletronics sold for a good five figure price. Back then these chips were to expensive to put in consummer level cameras and were used exclusively for scientific and industrial applications and now 10 years later we see a chip sort of like this used in a consummber level (although at the hight end) Nikon D3.. with the entire camera selling with a retail price of 1/10 the price of the bare CCD chip sold for 10 years ago.

The first digital SLR I saw was in 1984. I was in the "press box" for the flatwater kayak races during the 1984 Olympic games in Los Angeles and this one newspaper photographer had an early Kodak/Nikon (joint venture) digital camera. It shot black and white at low resolution. But was good enough for smaller sized newpaper quality prints. I remember he used an accustic coupled phone modem and a pay phone to send in his work after the event. He could not talk much about his camera. Ten years later DSLRs were common but exppansive, 20 years later (2004) "everyone" had digital cameras

Lovesong
Apr 22, 2008, 11:50 AM
A 24MP full frame sensor is very close to matching a 35mm film camera. With a full frame camera there is not much reason to have more pixels and good reasons not to have more. Eventually the price will drop to under $1,000 for a 24MP FF DSLR. Give it 10 or 12 years.


While I completely agree that there should be a point where the sensors would out-resolve the lenses of cameras, I think camera companies will continue to push the envelope on the MP and ISO race. Soon you'll be seeing ads for 30MP P&Ss that can go up to ISO 10000 (and give you a nice blurry smear for an image).

One thing I hope for is that in the near future small P&S cameras will actually be able to use larger CMOS sensors, which will actually increase the image quality coming out of those things. We've seen some of this miniaturization in cameras like the M8 (yes, I know it's a $5000 rangefinder, but it's still smaller than the D40) and the Sigma DP-1. We can only hope that with the decrease in CCD prices, you'll soon be able to find a decent spec'ed Canon Elph (or whatever) that will have an APS-sized sensor, and will fit into your pocket.

sonor
Apr 22, 2008, 01:01 PM
A 24MP full frame sensor is very close to matching a 35mm film camera

I'm not especially bothered about more megapixels, but I would like more dynamic range. That was the biggest disappointment when I moved to digital. Too often you have to sacrifice shadow detail or risk blown highlights. I'd like a few more stops.

DSLR high ISO performance is already much better than film and we're not far off with resolution.

You can draw comparisons with developments in digital audio recording technology where a perfectly acceptable standard has already been reached. You can now record at 24-bit, 192khz with easily affordable equipment - and that's more than enough...many engineers are still perfectly happy with 44.1khz. Dynamic range and frequency response is far better than with tape.

bonafide
Apr 22, 2008, 01:05 PM
Thanks for posting this.

This was a great article. At times a little too in depth for me but overall it worked.

I used the information contained in it to convince my wife to allow me to go from a point and shoot camera to a Canon 40D dSLR :) (Something I've been working on for about two months now). She just didn't understand why we needed such an expensive camera when we can buy "the same 10 mega pixel" camera for $300.

Haha.. Excellent work.

Woooo... I cannot wait to join the world of dSLRs!

cube
Apr 22, 2008, 01:06 PM
http://www.cambridgeincolour.com/tutorials.htm

theblueone
Apr 22, 2008, 01:12 PM
Wow. Thanks. I wish this had been available 6 months ago when I started looking for a DSLR. Surely, all this information is out there somewhere, but it's nice to have it all in one place where it's easy to understand.