Noise levels than and now?

[ken a.]

I am looking for a replacement for my three year old Powershot S30

and constantly read that the noise levels of P/S cameras become

extremely visible above 200. The S30 has a 3.2 MP sensor and was

given a maximum speed of 800, one stop faster than most P/S cameras.

I know that sensors have evolved to the current 7 and 8 MP crop, but

was wondering if today's camera sensors have less noise than the 3.2

MP sensors. If the sensor size has not changed over time, then

wouldn't the lower resolution sensors exhibit less noise at any given

speed setting when compared with the newer high resolution chips of

the same size? any thought on the subject would be greatly

appreciated as I am currently not able to print or use my good CRT

for printing/reviewing images.

[digitmstr]

There has been a little improvement but, with current technology, smaller sensors will have this limitation.

[mark u]

There has been one really significant advance - the Fuji F10 produces much lower noise than any other digicam on the market, and even offers ISO 1600 that is useable with noise reduction software. The downside is that the camera is just a consumer P&S, only offering scene modes rather than full control. If Fuji put their new sensor in a better body with good ergonomics, a decent lens and proper control I think it would rapidly take a large slice of the market.

[andrew robertson]

Too bad the F10 kinda sucks.

[tim_r]

I think you right Ken - The megapixel race has resulted in worse cameras.

 

I was in the same boat as you - My Canon S30 finally gave out on me a few months ago, and I was searching around for a replacement that had full manual controls (like the S30) and a high ISO for low light situations. I finally settled on the Canon S60 with the Caplio RX a 2nd place contender.

 

Honestly - If it wasn't for the extra 7mm on the wide end, I think I would be happier with the S30. The noise levels are definitely higher at an equivalent ISO than they were on the S30 and the extra 2 megapixels results in modest image quality improvements. (Generally you need 2x as many pixels along a linear direction - or 4x total pixels - to see significant improvements in image quality. For the 3 megapixel S30 this means I'd have to jump to 10 to 12 megapixels to notice a big difference. The reduction in pixel size however seems to increase the noise levels greater than linearly however.)

 

Once I get some free time I am going to look up some technical papers to see how sensor noise scales with pixel size for both CMOS and CCD. I'm guessing that you're often better off with the lower megapixel camera, which is why I didn't consider the 6 megapixel Canon S70.

 

By the way, DXO labs has a whitepaper on this. The paper is not very technical unfortunately but is worth a read to get an overview:

 

http://www.dolabs.com/en/mobile/news/pdf/DxO_Mpixel_WithePaper_execsum.pdf

 

 

Best regards,

 

Tim

[phule]

Personally, I'd replace a dead S30 with a S30. :)

 

The F10 would be a nice camera if it were not for the lack of manual control.

 

A newer camera with Noise Ninja or Neat Image can produce nice images. It takes more work but it is a possible choice.

[ken a.]

Good comments. Fortunately, my S30 is alive and kicking. Its just that I have missed more shots than I care to because of slow start-up and focusing times. I am looking at 7 and 8 MP models (and I would agree that anything less certainly does not make much sense from a resolution:value point of view), as well as a small DSLR, to complimant the S30 but people are alwyas writing about the noise levels at higher ISO settings. Are these complaints relative to other similar sized sensors, or to P/S cameras overall? I want to try and compare apples to apples as best I can in my evaluation.

[tim_r]

"Are these complaints relative to other similar sized sensors, or to P/S cameras overall?"

 

If you're talking about noise, then that just has to do with the sensor size and not the p&s enclosure per se. Small p&s will necessarily have small sensors, and thus high noise. In comparison, my Nikon D70's larger sensor takes great pictures at IS0 800.

 

I think the sensor technology is just not there yet for a really good, sensitive p&s. Maybe an old film p&s loaded with ISO 800 film for candid indoor shots beat out a digital p&s? I don't know. Digital SLRs seem to be far better than their film counterparts in almost all areas, but maybe it's not the same for p&s.

 

What I am planning on doing now in low light situations with the S60 is to set the exposure compensation at -1, use aperture priority mode with the lens wide open, shoot in raw so I can readjust the exposure afterwards, apply NeatImage, and hope for the best. Not the greatest of solutions, but I don't have any other good ideas.

 

You're right about the controls, startup and focusing times on digital p&s. These have not been optimized and as a result the cameras often feel like toys. The S60 and S30 tend to have to hunt for the correct focus (even in good light) and the manual focus controls are a joke.

[phule]

<< and the manual focus controls are a joke. >>

 

With regards to using hyperfocal distance with the lenses on these cameras, I disagree with that statement. Manual focus makes the camera very responsive (center-focus point shooting slightly less so but still better than AiAF).

[ken a.]

I frequently hear about setting P/S digital camers to manual focus and set the distance to hyperfocal, but that is not as easy as setting the hyperfocal distance with marked lenses like the older Nikon and Leica lenses, for example. The S30 sets it focus electronically and the scale is so small that even if you knew the hyperfocal distance, I am not certain that you could accurately set it. Also, this is a work around situation at best if you are working in fast changing conditions. A change in light changes the aperture, which changes the hyperfocal distance. Also, as a person who wears eyeglasses, good autofocus is a real blessing.

 

What confuses me is that Canon, for example, can put an extremely fast focusing unit in its tiny SD500, but not in its slightly bigger and more featured S70? Do they not think that somebody who buys an S70 for its manual controls would not also want a fast AF mechanism?

[johnclinch]

Hyperfocal on a digi caM is quite easy as depth of field is huge

 

were talking 7mm lens!

[phule]

<< The S30 sets it focus electronically and the scale is so small that even if you knew the hyperfocal distance, I am not certain that you could accurately set it. >>

 

This has been addressed by John's response.

 

<< Also, this is a work around situation at best if you are working in fast changing conditions. A change in light changes the aperture, which changes the hyperfocal distance. >>

 

Partially addressed by John's response. Also, can you not also adjust the shutter speed? The camera certainly supports it.

 

<< Also, as a person who wears eyeglasses, good autofocus is a real blessing. >>

 

I'm not sure what you mean by this. The point is to use the screen for composistion after setting the camera to manual focus. Have you ever done that in aperture priority or shutter priority mode? You might want to try it out. The focus window/view goes away when you hit the "set" button.

 

<< What confuses me is that Canon, for example, can put an extremely fast focusing unit in its tiny SD500, but not in its slightly bigger and more featured S70? >>

 

When was the SD500 released? early March 2005 What internal processor does it use? DIGIC II.

 

When was the S70 released? August 2004. What internal processor does it use: DIGIC I (or just DIGIC as it's called).

 

Two different cameras released at two different times. The SD500 is faster because of the DIGIC II chip and because of advances in technology since the S70. It also doesn't have a leaf shutter, RAW support, or half-a-dozen other things the S70 does. The comparison, in my opinion, is not valid.

[tim_r]

"With regards to using hyperfocal distance with the lenses on these cameras, I disagree with that statement. Manual focus makes the camera very responsive (center-focus point shooting slightly less so but still better than AiAF)."

 

The point, Rob, that I (and Ken also I believe) are trying to make is that the actual manual focus controls on the Canon S series are unweildy to say the least. It's necessary to push a button, use a dinky little rocker switch, and try and gauge by the little image on the LCD screen whether you've correctly set the focus. Have you tried it? Sure it can done, but you had better be shooting something which won't be moving anytime soon, and possess a measure of internal patience and serenity to boot.

 

Don't get me wrong - it's good to have, but it falls short of being generally useful, and thus I depend mainly on the finicky autofocus.

[phule]

<< It's necessary to push a button, use a dinky little rocker switch, and try and gauge by the little image on the LCD screen whether you've correctly set the focus. Have you tried it? >>

 

I use it all the time with my Canon A80. It's not difficult to set nor is it difficult to use. The screen has distance marks right on it. You don't have to be hyper-exact because the extreme DOF with these lenses takes care of the rest.

 

The "dinky little rocker switch" has to be used for all sorts of operations with any point and shoot digital camera. Why is this operation so different? Once it's set, you just go and shoot.

[phule]

<< and thus I depend mainly on the finicky autofocus. >>

 

Have you tried using the center-focus point only?

[tim_r]

"Have you tried using the center-focus point only?"

 

I'll give it a shot. I know I played around with it on the S30 but not the S60 (I just got the S60 a week and a half ago.) Maybe that's the cause of problems I've been having - the S60 doesn't seem to focus as well as the S30 did. Thanks for the tip.

 

Your points about the large depth of field that the digicam's short focal lengths provide are well taken. I'll try and exercise some patience and practice a lot with the manual focus on the Canon and see how good I can get with it! Maybe I was trying to be too exact.

[ken a.]

Rob,

I appreciate the detailed reply, but have a few questions. I know that we are dealing with a 7mm lens, but it would be helpful to have the information visually, as on older lenses. I do not remember hyperfocal distances in my head and I do not find them convenient to carry around on paper. Also, I am still not aware of what the distance is for this specific lens; John only said that it was a 7mm lens and it was easy to set. Forgive me for being literal, but that's how my mind works.

 

Granted, the SD500 is using a newer chip, but at the rate Canon is churning out new models, I am surprised that there is not an S75, not unlike the S45. From a marketing point of view, this criticism holds some validity.

 

Regarding autofocus and eyeglasses, its true that it is not relavent specifically to setting a hyperfocal distance, but the comment was more in general to the issue of manual focusing. I learned much of my photography on a Pentax Spotmatic 30 years ago, and while I like to have the ability to focus manually, it is one task that I do not miss now that I wear eyeglasses. And I do use the spot autofocus on the S30. It helps, but its still slower than I care for.

 

Dont't get me wrong, I think Canon and others have brought out many great advances in the imaging world. Its just that they seem to package their advances in ways that always leave me wanting more. And from the comments of others here and on other forums, I think that there are lots of people who share the same feelings.

[phule]

<< Rob, I appreciate the detailed reply, but have a few questions. I know that we are dealing with a 7mm lens, but it would be helpful to have the information visually, as on older lenses. I do not remember hyperfocal distances in my head and I do not find them convenient to carry around on paper. Also, I am still not aware of what the distance is for this specific lens; John only said that it was a 7mm lens and it was easy to set. Forgive me for being literal, but that's how my mind works. >>

 

I used this page for my calculations:

 

http://www.dofmaster.com/dofjs.html

 

The S70 (for example) is listed in the drop-down and the exact focal length of the lens is on the front of the camera or in the table linked to from the dofjs page.

 

My first exposure to this method of manual focusing was from this web page:

 

http://albert.achtung.com/cameras/A80/index7.html

 

<< Granted, the SD500 is using a newer chip, but at the rate Canon is churning out new models, I am surprised that there is not an S75, not unlike the S45. From a marketing point of view, this criticism holds some validity. >>

 

But we're not talking about a non-existent S75, we're talking about the currently available S70. No one but Canon knows when the next S-series model is coming out. It could be announced tomorrow with Digic III, mind reading and an espresso maker for all we know. :)

[ken a.]

Thank you very much for the links. The pages look very helpful, and I will study them more this evening when I have more time.

 

Regarding the espresso maker, please make mine a decaf. ;)

 

Thanks again,

 

--Ken

[demetri_p.]

One thing to remember about the s30 that most people don't realize is that it's iso ratings are 1 to 1.5 stops too conservative. In other words iso 400 on an s30 will give you shutter speeds equivalent to iso 800-1000 on cameras with accurate iso ratings. I couldn't believe it either until I tested it multiple times against my film slrs at the time. That would make it's iso 800 around 1600-2200 which is incredible but the noise makes it unusable at that setting. iso400 is passable to my eye, though.

 

Anyway, I did end up getting a fuji f10 and am thrilled with it despite the lack of exposure and focus controls. I find it to be fast with outstanding resolution and long battery life which are the downsides of the s30. I believe these two digitals are the best in the high iso game without going to an dslr, almost any of which will give you much better noise control.