Comments on: Poll: Megapixels vs. camera sensitivity

If you squeeze more megapixels onto a sensor of a given size, a camera works worse in dim conditions. So what's better, more megapixels or higher sensitivity?

[mreiher]

Sensitivity please!

Recently I went through great pains to pick just the right point
and shoot digital camera. I have a Canon Rebel XT, and an older
Olympus 4MP digital, but I wanted something to pop in my
pocket on trips.

Anyway... the camera we selected was a Canon. It's 10MPs and a
nice little camera. However, I've now found that the camera is
horrible at low light shots. Very grainy, blurry (at times) and poor
sensitivity. My older Olympus camera does a way better job with
the flash off (I don't like the flash most of the time because it
flattens the image).

In hindsight, I'd go back to the drawing board and find one with
better low light capabilities. I miss the sensitivity of the Olympus
and for my artistic shots I'll still use it or the Rebel depending
on the situation.

[ArtInvent]

Try a Fuji F41 point and shoot - high ISO bargain

The Fuji F series has been a sleeper in this respect for a while. These point and shoots have a larger than normal sensor and far better performance at high ISO than pretty much any other compact camera. The F30 and F31fd are no longer available but were IMO a pretty sweet compromise between resolution (6mp) and ISO performance. But even Fuji is screwing up and jumping on the megapixel race. The F51 and new F100 have gone up to a ridiculous 12mp which is pretty pointless with the lenses they put on a point and shoot. HOWEVER the F40fd is still available at 8mp, $150 with rebate, and it's pretty sweet. At ISO 400 it looks about as good as my Canon Rebel XT at the same 8mp resolution.

[yelocab]

Sensitivity is more important.

I think for the average user, 8 megapixels is the highest that they would need. (I have mine set to 5, which gives me good quality vs. file size). How many regular users are going to blow up a picture to 16x20 vs. taking shots of junior's birthday party or vacation pix?

[afaet]

The most important attributes are sensor size, sensor size and sensor size.

The bigger the better, pixel count and sensitivity will follow?

[asquaredflyer]

You missed it

Stephen; You missed it.It's not only megapixels and sensitivity. You aren't factoring the sensor size and the size of each pixel element in your equation. Yes, the number of pixels matters. Yes, the sensitivity matters. But a "full frame" sensor with high sensitivity and 20+megapixesl and large light collector sites will make the difference.

Your two elememts in an oversimplified equation don't make the whole story of picture quality.

Also, tires usually don't get mpg;-) (See your photo caption)

[Shankland]

I still think it's a relevant comparison

I think it's fair to compare 10MP/ISO 3,200 to 12MP/ISO 1,600; that's what Canon did with the 40D vs the Rebel XSi, which have the same size sensors. Likewise, in the previous generation comparison, Rebel XTi had 10MP and ISO 1,600 to 30D's 8MP and ISO 3,200. I was trying to holding sensor size constant to sidestep that issue.

You can get better pixel size and therefore sensitivity if you go to a full-frame sensor, but that's *way* more expensive to manufacture. That's an entirely different tradeoff, and I was trying to compare apples to apples. In the compact camera area, manufacturers have more choice (Canon increased the sensor size on the G9 slightly from the PowerShot G7 to the G9), but there, too there's a big price penalty to using a larger sensor.

And thanks for the mpg/mph catch!

[ciphoto]

Sensor sizer, pixel size

First sensitivity is key, and..
Before I went to digital, I did a lot of reading etc..., and my
general feeling is that is big fatter pixels are better. The more
they cram into a small area just increase noise and other issues.
No consumer really needs more than 6 anyway. IMHO

MP are a good marketing tool for the mass population that really
don't understand photography, printing and just use the auto
and scene setting on the cameras any way.

[grabshots]

Sensitivity

What good is lens resolving power & sharpness if a lack of sensitivity inhibits acquisition of a strong image? My 7-megapixel images look okay on a 46-inch TV but I would like to own a 15+mp camera when the drawbacks are overcome and the price is affordable.

[wyomingsundancer]

Detail

The speed is very important. However I really miss using an old medium format film camera. I could take a picture of a vehicle with a 50mm equivalant lens from several hundred feet, keep cropping to the point that the lettering on the tire of the vehicle was readable. It would take at least a 32 megapixel digital camera to remotely do this.

[Shankland]

If you like it, keep shooting film

I run into a lot of people who like film (medium format and otherwise) for all kinds of reasons. Keep shooting it if you like it. A good friend of mine carries a point-and-shoot and a Mamiya medium-format film camera a lot. He gets the negs developed and then has the ones he likes scanned so he has an electronic copy. You won't be able to e-mail the birthday party pictures to your grandparents the same afternoon, but film still works for now.

[shadowself]

It's not that simple a trade

IF (huge IF) you lock yourself into front side illuminated CCD technology then this is true. You trade sensitivity for pixel density.

However, make the break to backside illuminated CMOS and you can get a jump of a factor of 4 or more in sensitivity at the same pixel density. Thus a 16 Mpixel backside illuminated CMOS camera can have the same sensitivity as a 4 Mpixel frontside illuminated CCD camera.

If it is an interline transfer CCD to which we are comparing as a baseline the difference in sensitivity can be a factor of eight or more.

This article should mention that users, especially the cutting edge users, should push the camera vendors to the newer, better technology.

[alegr]

Huh?

I happened to work for a while designing CMOS cameraphone sensors (though not anymore in that field). And I'm at loss, trying to understand what you mean in "backside illuminated". Do you mean pinched diodes? 4T shared?

[zakb7]

Right on target

Cramming more megapixels into an APS-C sensor is like taking the same pizza and cutting it into more slices. I find it a little surprising that 95% of those polled choose sensitivity over megapixels, when all I ever see on various sites are comments like, "I only wish the Canon 40D had 12 megapixels - jumping to 10 megapixels from 8 doesn't seem like much of an improvement." Or some such thing.

Just goes to show how much marketing affects camera buying decisions - never mind actual, real-world performance (not talking about closeups of test charts, either). I'm so glad you mentioned getting great 20x30 prints out of your 8mp camera, because that's not what the kid at Best Buy will tell you.

That ISO 6400 crop of the D3 is simply astounding, by the way. Looks like an ISO 1600 crop from my Digital Rebel.

[aaydogan]

What about dynamic range?

APS-C sensors with 12 mp is more than adequate for almost all
photography needs and can have decent sensitivity up to 6400
ISO. As the author noted, the the Nikon D3 with it's 35mm size
sensor and 12 mp has even greater sensitivity. What's lacking in
these discussions is the characteristic that hasn't carried over
from film, wide dynamic range. Other than Fujifilm no
manufacturer has addressed this issue and
social/wedding/portrait photographers like me it's critical. It's
the difference between shooting a wedding with high contrast
consumer Fuji Superia and using a low contrast film like NPS. In
the former the bride's dress is blown out white with no detail
and the groom's back tux is just one shade of black. In the
latter the full tonal range is available. I want/need this choice in
my digital cameras, too. And....I don't want to constantly screw
around with each image in RAW.

[sroussey]

Here here!

Taking three pictures at different settings and merging them in photoshop sucks. I have a high end DSLR, but won't replace it until the dynamic range is better.

[llungster]

cake and eat it too

Digital users are spoiled. We've come to expect our camera to do everything and do it all well. Remember that the image sensor is like film - it has only one real native speed. All other speed settings are non-optimal and are compromises. It's like pushing film but we can't replace the sensor with a different speed unit (now wouldn't that be cool!). I've been told that today's sensors are optimally equivalent to about ASA100. Imagine pushing ASA100 film to 6400 or 25000. Is that truly reasonable? The fact that existing SLRs offer such wide range of speeds is pretty darn amazing.

Another aspect that's mostly ignored is the required image processing off the sensor. I'd like to see more direct RGB sensors (like the Foveon used in the Sigma SD14). Several patents have been filed so hopefully the big boys in SLRs will be following suit with such cameras soon. I'd take direct RGB per pixel sensors over one capable of super wide lighting conditions. Image quality first!

[Shankland]

Pushing film vs. pushing digital

It's true that there are image quality compromises when you push film or digital. I used to push T-Max 400 to 3,200 for dark shooting, and yep, it sure was grainy, but grainy beats nothing when you're taking pictures for the newspaper. If you look closely at Sports Illustrated photos, you'll often see noise speckles in the shadow areas, so clearly even professionals with the highest-end gear are pushing the same image quality envelopes to get sharp pictures. Personally, though I'm discouraged that the megapixel race hasn't slowed down, I am encouraged that at least in the SLR category the manufacturers seem to be evaluating the tradeoffs fairly carefully.

[cmstratton]

megapixels are easy

When digital camera were first proliferating, megapixels was an easy measurement camera makers could promote that the general public would understand. It was easy marketing that more megapixels meant better images and therefor higher value on the camera. Now that the general public is a little more pixel-savvy so to speak, other options need to be promoted to differentiate in the marketplace.

[macphotos]

6400 ISO

I took a picture about 9:30 a.m. back in the fall at 6400 ISO, you
little or no noise, just remarkable.

Canon 1D Mark III, all before the infamous focus issues

[www.hdgreetings.com]

Not even a close call...

Pictures could look pretty good back at 4 megapixels. With 10mp being pretty common now, sensitivity is absolutely more critical.

Do you know how many people across the world have shot poor quality pictures because of dim lighting?

The number of people who shoot poor quality just because of lower MP count is very very low.

[fazalmajid]

High ISO claims are often deceptive

Just aas ghetto blasters boast of absurdly high watt ratings (without mentioning the blood-curdling levels of distortion you would get if you actually pushed that far), many unscrupulous camera makers put high ISO levels on cameras for spec sheets' sake, but they are completely unusable.

Many compact cameras claim they can do ISO 1600, but there is no compact camera out there that does even ISO 400 acceptably (apart from Fuji's now discontinued F31fd). Similarly, even DSLRs made by Sony, Olympus and Panasonic advertise ISO 1600 but don't deliver the goods.

Sometimes manufacturers try to cover up a sub-par sensor with heavy-handed noise reduction that gives the impression of low noise, but by wiping out all fine detail, effectively decreasing resolution.

High ISO ratings would only be meaningful if the manufacturer would quote the signal to noise ratio at the max ISO, but there is no accepted standard for measuring it, and don't expect sleazy camera marketers to stop playing deceptive games anytime soon.

[skrubol]

I agree 100%

The story seems to be equating the highest ISO speed the camera offers to sensitivity. This simply is not the case. Have you looked at images from the D3 at iso 25000? True, a grainy image is better than no image, but at that setting not much. Color pictures are pretty much unusable (conversion to BW makes them much more pleasing.) It's probably more accurate to compare the Nikon's iso 12800 to the 1DsIII's 6400.
Also, the comparison between the XSi's 1600 and the 40D's 3200 is also a little misleading. If there is any sensitivity difference between these cameras (which I assume there is, I have not read enough about the XSi yet,) it is not a full stop. I'd guess closer to 1/3 stop. The 40D has a higher iso setting mostly because it is a higher-end camera and Canon needs differentiators to get people to spend double the money on it.

[amigabill]

weird poll choices

I thought the two options inthe poll were strange considering this topic. I'd have expected more of a 3MP good sensitivity vs 7MP bad sensitivity poll, than comparing 10MP and 12MP. My camera is 7MP, one of the earlier ones. My biggest complaint about it is light sensitivity. I can frame up a picture that looks great on the screen, but as soon as I push the button to take my picture it ends up a dark rectangle. There's picture in there, as I can transfer it to a PC and crank up the gamma to make it worth having, but I'm totally clueles as to why things look so good before I press the capture button, and so horribly unseeably dark after pressing that button. It sucks, and yes, I'd trade down in MP to get a decent picture without messing with gamma settings later on a PC just to find out which black rectangle is which, let alone make it savable. I vastly prefer the 5MP camera I got for my mom as things just come out so much better than on my 7MP. But this article is comparing a "good" 10MP to a "bad" 12MP. This theoretical "good" 10MP is still a huge upgrade from my "bad" 7MP camera, so the whole argument of which is more important suddenly seems rediculous and irrelevant.

[fazalmajid]

DR and ISO usually go hand in hand

Because you need a deep electron well to give more dynamic range, something that usually goes hand in hand with bigger, more sensitive pixels.

[alegr]

Car wheel shot

"Sure, there's lots of noise and the colors aren't as vivid as they could be"

Just consider how horribly grainy a real ISO 6400 silver halide film would be.

[Shankland]

no kidding

I offered those qualifiers to be sure nobody thought I was fooled into thinking ISO 6400 is buttery smooth on the D3. But believe me, overall, I'm impressed.

[djacobow1]

isn't noise, not sensitivity, per se?

You define sensitivity in terms of ISO, but lots of cameras are happy to turn up the gain as high as you like (or nearly so) and provide you with a what appears to be a sensitive, if outrageously noisy sensor.

Some of the cameras also apply some pretty heavy-handed and potentially funky looking NR to achieve high ISO without appearing noisy. I'm not sure this is a satisfying tradeoff, either.

My XTi goes up to 1600 and I never use it there. The images are a mess. In fact, 800 is pretty awful, too.

If I had my druthers, cameras would advertise the size of their active collection sites along with MPix, or better yet, real SnR values. Not gonna happen, though.

-- dave j

[irperez]

Men usually lack the sensitivity, but lately I'm hating all cameras!

Its about time that sensitivity is being brought up!!! I can't take pictures inside or in my church. Its too dark. My camera just doesn't cut it. I'm a perfectionist and I hate it when my pictures come out blurry or dark with tons of noise. The camera industry has to get off this megapixel high and start creating cameras that offer better quality pics even in dark situations. I want to buy an SLR but with the steep prices for the quality I just can't do it. SO I'm waiting until the industry changes their attitude and makes better quality cameras.