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Author Topic: Replacing a Point and Shoot & Camcorder with 1 Camera  (Read 10777 times)

neuroanatomist

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Re: Replacing a Point and Shoot & Camcorder with 1 Camera
« Reply #15 on: September 12, 2011, 07:24:57 PM »
I already knew that DSLRs achieved better IQ due to the larger sensors, but I also assumed it was related to the lens being bigger in diameter therefore capturing more light.

Not per se.  Lenses have f/numbers (commonly referred to as aperture), which are a ratio of focal length to iris diaphragm diamater.  Lenses are also designed to project a specific image circle diameter.  With a smaller sensor, that image circle can be smaller, but the f/number ratio holds constant.  So, the S95 is f/2 at 6mm (which with the small sensor size means a field of view equivalent to 28mm on a FF camera).  That means the iris diaphragm must be 3 mm in diameter (6mm / 2 = 3mm).  Compare that to something like the EF 135mm f/2L, which needs an iris diaphragm of 67.5mm.  So, the 135L needs a lot more glass, and is a lot bigger and more expensive.  But, both that big lens and the tiny S95 lens are delivering f/2 - meaning that per unit area, the amount of light hitting the sensor is exactly the same for the two cameras.  But, that's light per unit area.  A bigger sensor captures more total light, and that's what yields the better IQ (in particular, lower ISO noise).

But in the case of (I’ll use current models so it’s not as speculative) S95 vs. SX30, the S95 has a larger sensor with a smaller lens, and vice versa.  Does the larger piece of glass in the SX30 have any IQ advantages at all, or is it all about getting that "super " zoom?  I don’t want to be that consumer enamored by a gimmick, but on the other hand, 35x zoom is pretty useful assuming it’s not destroying IQ.

It's really all about getting that super zoom.  In fact, with smaller lenses it's often easier to correct the aberrations than  with larger lenses. 

I assume CMOS is superior to CCD.  Is that always the case?  I see the S95 uses a CCD and both Sonys use CMOS.

Not really.  Different, with different strengths and weaknesses.  CMOS sensors are faster (relevant for 1080p video and high-speed stills at high resolutions), but tend to be noisier and have less dynamic range. 

Another question: Assuming the S95 (and its successor) does have a larger sensor and better IQ than either of the Sony cameras above or Canon SX series, what other point-and-shoot cameras (Canon or otherwise) have a large sensor?  Sensor size has not been on my radar until now.

The Canon S95/G12 are among the largest.  The sensor in the Panasonic Lumix LX-5 is slightly larger.
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Re: Replacing a Point and Shoot & Camcorder with 1 Camera
« Reply #15 on: September 12, 2011, 07:24:57 PM »

elflord

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Re: Replacing a Point and Shoot & Camcorder with 1 Camera
« Reply #16 on: September 12, 2011, 07:40:23 PM »
Neuroanatomist, thanks so much for that explanation.  I was totally unaware of the sensor being a different size between those models.

Sorry for all the questions, but I’m just trying to understand the sensor size to picture quality relationship:

I already knew that DSLRs achieved better IQ due to the larger sensors, but I also assumed it was related to the lens being bigger in diameter therefore capturing more light.

The main thing that results in very large lens elements is the absolute aperture size.  The aperture width increases in inverse proportion to the f number and in direct proportion with the lens focal length. Lens focal length increases linearly with sensor size.

So for example, the aperture on an 840mm f/5.8 full frame lens (same fov as the SX30IS) would be about 14cm wide. The front element would need to be somewhat larger than that.

So larger sensors require larger lens elements as do low f numbers, but the larger lens elements don't in themselves result in better image quality.  So for example, the 35mm f/1.4L produces excellent images, and it's not a very large lens.

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But in the case of (I’ll use current models so it’s not as speculative) S95 vs. SX30, the S95 has a larger sensor with a smaller lens, and vice versa.  Does the larger piece of glass in the SX30 have any IQ advantages at all, or is it all about getting that "super " zoom? 

You need a larger piece of glass to get the longer effective focal length.  The reason they use such small sensors is that a full frame sensor would require a larger lens than Canon's 800mm f/5.6 lens. 

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I don’t want to be that consumer enamored by a gimmick, but on the other hand, 35x zoom is pretty useful assuming it’s not destroying IQ.

It's a trade off. Larger sensors result in better image quality, especially low light performance. Prime lenses and zoom lenses with a relatively short zoom range (about 3x or so) usually perform much better than super zooms. If we all cared about quality at all costs, we'd all use medium format cameras with primes.

But there are tradeoffs. Having said that, the fact that zoom range is very visible to the naive consumer whereas sensor size and maximum aperture are not, means that the typical user tends to give up a lot in terms of low light performance to get more zoom.

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I know this is the Canon forum, but does anyone happen to know if the Sony DSC-HX9V and DSC-HX100V use the same sensor? 

They both use small 1/2.3" sensors. All super zooms use small sensors. The 30X zoom camera weighs more than twice as much.


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Another question: Assuming the S95 (and its successor) does have a larger sensor and better IQ than either of the Sony cameras above or Canon SX series, what other point-and-shoot cameras (Canon or otherwise) have a large sensor?  Sensor size has not been on my radar until now.

You won't find any super zooms. Off the top of my head, the Canon S95, Canon G12, Olympus XZ1 and Panasonic LX5 are some of the leaders among compacts. You won't get a wide zoom range in any of these -- they're in the 5x ballpark. You can find more by searching snapsort.com, here's a starting point:

http://snapsort.com/explore/best-digital-cameras/1.7-sensor-size

 If you want good image quality in a compact, these are the ones to look at.

The mirrorless cameras (e.g. micro 4/3 like Panasonic GF3, Olympus EP3, Fuji X100) are small and have almost SLR sized sensors, but even a 3x zoom is quite large on one of these -- because you need more glass to cover the big sensor.

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Re: Replacing a Point and Shoot & Camcorder with 1 Camera
« Reply #17 on: September 12, 2011, 08:44:22 PM »
neuroanatomist & elflord,

Thanks so much for taking the time to explain all this to me.

But there are tradeoffs. Having said that, the fact that zoom range is very visible to the naive consumer whereas sensor size and maximum aperture are not, means that the typical user tends to give up a lot in terms of low light performance to get more zoom.
That makes perfect sense.  24 hours ago, I was thinking: "Get the biggest zoom, highest resolution and FPS in video, and best features."  I'm sure that line of thinking is what Canon and Sony are counting on.  Even the way the SX30 looks is "impressive" and causes the consumer to assume it's better quality than a puny little S95.

On the other hand, I don't think it's all smoke and mirrors... for a guy like me that is trying to find a single "do everything" camera, I might be willing to sacrifice some quality to have all the modes and features I want.  Zooming in to see my child in the band on a football field might be more important than a slightly less-grainy indoor shot with no flash.

It is becoming very clear to me now why the G and S series of Canon PowerShots are so popular among the DSLR crowd.  I am definitely not ruling them out, though it sounds like I should keep waiting if I want the G series since the G12 is getting long in the tooth, and apparently no G13 in 2011.  I do really want 1080p video too, so that would be reason enough to wait if the G-series makes the cut.

However if the S100 has everything I'm looking for except a big zoom, and now I know there is no HQ options with a big zoom due to actual physics... I may go for that.

I have to admit though, the Sony HX100V is still looking really good to me.  Here are some reviews I watched / read:

http://www.cameralabs.com/reviews/Sony_Cyber-shot_DSC_HX100V/

http://reviews.cnet.com/4505-6501_7-34532712.html (video review)

http://reviews.cnet.com/2300-6501_7-10009052.html (sample photos)

http://www.digitalphotographywriter.com/2011/02/nikon-coolpix-p500-vs-canon-sx30is-sony.html
This guy picked the Nikon P500, but I ruled it out based on other reviews... but he did put the Sony above the Canon SX30.

http://www.youtube.com/watch?v=aNNExy80yEc (obvious fan-boy, but still informative)

elflord

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Re: Replacing a Point and Shoot & Camcorder with 1 Camera
« Reply #18 on: September 12, 2011, 09:31:06 PM »
neuroanatomist & elflord,

That makes perfect sense.  24 hours ago, I was thinking: "Get the biggest zoom, highest resolution and FPS in video, and best features."  I'm sure that line of thinking is what Canon and Sony are counting on.  Even the way the SX30 looks is "impressive" and causes the consumer to assume it's better quality than a puny little S95.

On the other hand, I don't think it's all smoke and mirrors... for a guy like me that is trying to find a single "do everything" camera, I might be willing to sacrifice some quality to have all the modes and features I want.  Zooming in to see my child in the band on a football field might be more important than a slightly less-grainy indoor shot with no flash.

Again, this is where the zoom fools people. The prevailing myth is that the camera with a long zoom lens is more "versatile" because you can use it at a variety of focal lengths. The problem in this thinking is that such lenses only work well under very favourable lighting conditions. Under low light, they become close to unusable -- you end up requiring either an unusable shutter speed or an unusable ISO setting. And that's assuming that the camera is able to autofocus under the lighting conditions (harder with a slow lens).

If you're taking family pictures -- a camera with a larger sensor will produce much better looking portraits. Shallow depth of field makes for much better looking portrait shots. That's why wedding photographers use f/2.8 24-70mm 70-200mm zooms  and sometimes even primes -- they are shooting with indoor light and they are shooting lots of candids which look much better with less depth of field.

So in some ways, the brighter lens/sensor combination is more versatile. Most of the pictures I've taking are either indoors or under night time light. For this, a slow lens/sensor would be unusable.

Moreover, most users aren't going to benefit very much from having the 400mm-800mm range available. You need a very fast shutter speed (or a tripod) to get good images at those focal lengths, and they aren't useful for general purpose photography. Even sports photographers often get by with "only" 200mm or 300mm lenses.

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It is becoming very clear to me now why the G and S series of Canon PowerShots are so popular among the DSLR crowd.  I am definitely not ruling them out, though it sounds like I should keep waiting if I want the G series since the

Just my opinion, but if you're getting something as big as the G, you will get much better image quality from a micro 4/3 camera, and they are about the same size as the Canon G series.

neuroanatomist

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Re: Replacing a Point and Shoot & Camcorder with 1 Camera
« Reply #19 on: September 12, 2011, 09:36:57 PM »
... for a guy like me that is trying to find a single "do everything" camera, I might be willing to sacrifice some quality to have all the modes and features I want.  Zooming in to see my child in the band on a football field might be more important than a slightly less-grainy indoor shot with no flash.

It is becoming very clear to me now why the G and S series of Canon PowerShots are so popular among the DSLR crowd.

Exactly - different markets. I love my S95 because a already have a dSLR (two, actually) and a bunch of lenses ranging from 16mm to 640mm FF-equivalent.  But carrying all that isn't always convenient - thus the S95. It and the G12 shoot RAW and offer a host of manual controls that dSLR shooters are accustomed to, and deliver the best IQ for size.  If I had only one 'do everything' camera, it would probably be a superzoom - in fact, before getting into dSLR photography (returning from film SLRs after a long gap), my one was a superzoom predecessor (Olympus C765UZ, UZ meaning ultrazoom, a 38-380mm FF-equivalent).
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Re: Replacing a Point and Shoot & Camcorder with 1 Camera
« Reply #20 on: September 12, 2011, 10:20:50 PM »
Thanks again elflord  and neuroanatomist for your informed opinions.  I have much to think over and research... but I'm enjoying it.

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Re: Replacing a Point and Shoot & Camcorder with 1 Camera
« Reply #20 on: September 12, 2011, 10:20:50 PM »