Sensor sizes -- Can somebody explain this? [Archive] - Glock Talk

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Curley
04-24-2008, 16:44
As a newcomer to the world of digital cameras, I'm puzzled about something I keep seeing over and over on all the digital photogrpahy information sites on the Web.

The consensus is that digital SLRs make better pictures and have much less noise than point-and-shoot cameras because they have much larger sensors. I'm talking about physical size, not the number of megapixels. (In fact, another thread here graphically shows the size differences. Wow!)

But I've never seen an explanation as to why some camera maker hasn't put a big sensor in a point-and-shoot camera. Does anyone know why that hasn't been done?

After all, some non-DLSRs are just as big as DSLRs -- i.e., the Panasonic FZ50 and Fujifilm S6000, S9000 and S9100 -- so it doesn't seem that the size of the camera is the limiting factor, because all those cameras have the smaller sensors.

I love SLRs, but it seems like a digital SLR is kind of a melding of old and new technology. I mean, with all the technological advances in digital cameras, mechanically operated shutters and mirrors seem kinda out of place. :dunno:

hwyhobo
04-24-2008, 17:05
But I've never seen an explanation as to why some camera maker hasn't put a big sensor in a point-and-shoot camera. Does anyone know why that hasn't been done?
Money. Cost of sensors rises exponentially with size.

Another reason is, many newcomers are in love with megazooms. It is technically impossible to make a 28-450mm lens for a large (APS-C or FF) sensor and maintain cost sanity (and size). Also, if you were to pay that kind of money for a lens, you would expect technical excellence, and it is pretty much impossible to make a good lens with such a range, period, at least with current technology. Amateurs will be much more forgiving because the lens is built into the cost of the P&S camera, but when you have to shell out several grand, your expectation would change dramatically.

I love SLRs, but it seems like a digital SLR is kind of a melding of old and new technology. I mean, with all the technological advances in digital cameras, mechanically operated shutters and mirrors seem kinda out of place. :dunno:
There are pluses and minuses. Noise is a minus for an optical viewfinder. Clarity is a plus. Also, with current technology, it would be difficult to make Electronic Viewfinder (EVF) that would allow you to assess focus as well as a good pentaprism-based optical viewfinder. On the other hand, it would be nice to be able to see live histogram in the viewfinder, wouldn't it? Oh, well. I am sure some time down the road the EVF will mature enough to become mainstream even in high-end cameras.

JimBianchi
04-24-2008, 17:35
As part of my book on photography (due to be e-published this summer) I have compiled a very good example of image sensor size comparisons.

<a href="http://s191.photobucket.com/albums/z27/VegasPigeonKiller/?action=view&current=SensorSizecomparisoncopy.jpg" target="_blank"><img src="http://i191.photobucket.com/albums/z27/VegasPigeonKiller/SensorSizecomparisoncopy.jpg" border="0" alt="sensors"></a>

Basically the above image is 8x10 as a reference.

Most point and shoot cameras have sensors that are .3 (7mm) inch across on the long side. (Some are slightly smaller also)

The real reason to keep the sensors small is cost the second being camera size and features. Bigger sensors need more power, better processors/electronics and that means something else has to be left out. (Heat is an issue too to a lesser extent)

Recently Ricoh (GX 100) introduced a high-end pocket camera that has a comparatively huge sensor in it. The camera is nice but limited to lower ISO setting and has a short zoom lens for about a grand. (Side by side at ISO 400 the Canon flagship wins)

Canons flagship G9 (A650 is the same camera without the bells/whistles and hotshoe for less than half price) is considered by many to be the finest digi-cam around and it does it with a small sensor but a great processor and outstanding software.

Some point and shoot digi-cams can compete directly with DSLR's if professional techniques such as great lighting are used and print size is under 8x10. (That is not a miss print) This is the whole point of my book.

DeadMansLife
04-24-2008, 19:16
I'm talking about physical size, not the number of megapixels.

From another board:

you'd then need larger lenses to cover the image area. Which puts you back into DSLR-size territory

Thread can be found HERE (http://photography-on-the.net/forum/showthread.php?t=491104)

DeadMansLife
05-07-2008, 19:50
Maybe it can be done. THIS ONE (http://www.pcphotomag.com/cameras/still-camera-reviews--comparisons/first-look-sigma-dp1_3.html) has a sensor slightly smaller than the Canon XTi.