More Savvy Shopping

By Ctein

Last column I presented some rules for getting the most for your dollar when thinking about buying new gear. Here are some more to further refine your sensibilities.

You aren't buying an average, you're buying a camera.

A distressing number of comments that I read run along the lines of "I would never buy camera X because...it's made by A and B makes better cameras/it has a small sensor and they're all crap/it has too many pixels to produce good quality/etc."

Comments like that are not the hallmark of savvy shoppers. Broad rules of thumb are good ones to tell your neighbor or relative who doesn't know much about cameras, when you don't want to take the time to look at individual models for them. Very sensible.

But when it comes to your own shopping, it's not. Indeed, large sensor cameras produce better quality than small sensor cameras...except when they don't. And higher pixel densities produce poorer image quality than lower pixel densities...except when they don't. For every general rule like this, there are exceptional cameras. In fact, no camera out there performs according to the average. It will always be better in some ways and worse in others, and usually in some particular characteristic it will turn out to be much better or much worse. If that happens to be the characteristic you especially care about, then relying on the average wisdom is going to be a poor use of your dollars.

I made this photograph at ISO 100 with my Fuji S100fs. Although it has a sensor 2.5 times smaller in dimension than the Nikon D200 (hence, pixels six times smaller in area) and cost only half as much, at low ISO's the picture quality is identical. It's an exception to the rule that bigger means better. Exceptions are not the norm (that's why we call them exceptions) but they're ubiquitous.

Concern yourself with how the camera of interest performs, not with the mean of all the cameras in that class.

Numbers don't mean much if you don't know what they mean.

Numbers don't tell you more than words or (more importantly) pictures, especially if you're less numerate than literate. I can tell from reading posts that many people are. Here are some basics. First, all digits are not significant. Just because a posted test result has four digits, it doesn't mean all four of them are accurate or meaningful. Don't sweat the fine details, look at things on a bigger scale. Don't obsess over numbers you don't understand. When cameras are ranked on an arbitrary scale on some website and their reading differs by one part in 100 or even less, it doesn't really matter whether or not you understand why the ratings differ. It's an arbitrary system and they're close enough that doesn't matter.

What's significant and what isn't? Well, pixel counts, pixel densities, and sensor dimensions that don't differ by at least 30% just plain aren't. Even in terms of the aforementioned, maligned averages, they won't produce visually significant differences. Resolution figures that differ by less than 15% are also not significant. You can't see that small a difference. Sensors speeds that differ by less than half a stop just aren't worth worrying over.

Now, go and spend wisely, but not too well.

Ctein

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Comments

[Fred]

Re: Numbers don't mean much if you don't know what they mean.

"Although its sensor (linear) dimensions are 40 percent of those of the Nikon D200 (hence pixels one-sixth the area)" might be easier to grasp than "Although it has a sensor 2.5 times smaller in dimension than the Nikon D200 (hence, pixels six times smaller in area)…"

However I agree with the premise of the article and enjoy your blog.

[David Bostedo]

Re : Numbers don't mean much if you don't know what they mean.

That's exactly what scares me about the DxO Mark site. As you've mentioned, some people just won't be able to use the site. But that won't keep them from quoting the numbers as though they are law, and determine absolutely which camera is best...

[ctein]

Dear Fred,

Everyone thinks they're a friggin' editor!

pax / Ctein

P.S. [VBG]

[Tanya Plonka]

A lot of it also depends on how you use it. People really get caught up in high ISOs, when really it's only the pros who understand lighting who can crank that up whereas the average user will still get a ton of noise.

[David]

Lovely photo.

[Jay Moynihan]

Really like that photo.

[J Fallon Dollard]

David,

DxOmark rates the measly 12 mp Nikon D3 and D700 above the 24 mp plus Sony and Canons for image quality of the sensors. Why? Better pixel pitch (bigger light buckets).

So one not fear the DxO metric, one should use it, and the otherwise accessible technical papers, to help make an informed decision. If, of course, you are interested in finding a balance between the sensor and the glass it hangs on.

BTW : DxO ranks the Fuji FinePix S5 and S3 Pro cameras as having the best dynamic range!

[ctein]

Dear David & Jay,

Thanks!

It's more saturated than I intended. There's something in the color management workflow in Photoshop or Mac OSX I haven't got a handle on. JPEGs I generate in Photoshop look OK when I view in in Photoshop or with the Preview app, but if I open them up in a browser window they are a lot more saturated.

Usually I allow for the 'windage.' I forgot this time.

If someone reading this understands what's going on, I'd greatly appreciate some education.

pax / color-challenged Ctein

[Sean Murphy]

The best camera is the one in your hand.

Not the one with the megapixel-pitch-cmos-96bit tech you want next. When spending the kind of money new digtial cameras cost, some due diligence is required, but shoot with the darn thing, print something!

Recently, while printing pictures from my D40 on some of the newer baryta papers on an Epson 2200, I was struck by how none of the greats of the past (fill in your favorite photographer here) ever had access to anything like this gear. We are in an era of embarrasing riches.

ctein, when you make your jpeg, are you embedding your ICC profile?

Sean Murphy
Silver Photon Studios

[Mark]

Convert your pic to sRGB. It should correct your problem.

[Andre]

PS Your photo looks more saturated, not less, when rendered in its embedded Adobe RGB profile (ie viewed in Safari or downloaded and viewed in Photoshop). At least on my system...

[ctein]

Dear Mark and Sean,

No, that's not it. But thanks for trying to help.

For the record, it happens whether the embedded profile is AdobeRGB or sRGB-- the image as displayed in both Firefox (3.0.5) and Safari (3.2.1) is way too saturated (and, BTW, looks the same with both profiles embedded). That's the opposite of what one would expect with working in AdobeRGB space and displaying with an sRGB app.

If I save the jpeg from Photoshop with no embedded profile, then it looks wrong in the browser in the expected way (lower saturation).

What I can't figure out is how to get it to look RIGHT.

pax / Ctein

[Andre]

As far as I know many (most?) browsers don't support color profiling at all. I think they just assume everything is sRGB. I checked Firefox 3.05, IE 7 and Safari 3.2.1 on my PC and only Safari recognized any of the color profiles. You can check your browser here:

http://www.color.org/version4html.xalter

[Ctein]

Dear Andre,

Cool test!

Under MacOSX 10.4.11, both Firefox (3.0.5) and Safari (3.2.1) are supporting v2 and v4 profiles.

I don't think it's a browser problem, anyway, but a Photoshop or MacOSX problem. I just don't know how to circumvent it!

pax / Ctein

[Bahi]

Ctein: do a quick check of the ColorSync Utility, in /Applications/Utilities. Under Devices, make sure that the display that you're expecting to see as default is listed as such by checking for the blue light next to its name. Once you've made a change, log out and back in to see the effect of your changes.

I know this sounds like the least likely cause but there's something wonky about the way some Apple applications, including Safari and Aperture, link profiles to specific application windows. It may not be the problem you're having but it sounds very close - it's usually the last frustrating step for anyone to get right when they're running a pro web site, a photo blog or even a Flickr account. I consider it an OS X bug. It's reproducible and I've reported it.

Anyone else finding the same problem and capable of writing a decent bug report should (please!) visit https://bugreport.apple.com using a free ADC account that takes just seconds to set up.

[David Dyer-Bennet]

And if shopping sensibly by these standards (which I fully agree with) results in your using a camera that your friends regard as clearly inferior -- SMILE!

Especially smile when your friends are astounded by your photos. Because they "know" that your camera is inferior, so the credit *all goes to you*!

[ctein]

Dear Bahi,

Thanks; you figured out the problem for me! Although I don't know if the problem is in the OS or the application.

I *am* running dual displays. It occurred to me that rather than go through the business of rebooting the system, I could check out your hypothesis simply by comparing the photograph in the browser window to the way it appeared in Preview on both screens. Sure enough, when I had both instances of the JPEG open on the MacBook screen, they looked identical. When I dragged them to the Cinema Display screen (which was not set as my default, but is where I do most of my web browsing) the Preview window properly switched display profiles when the majority of it had crossed over to the Cinema display. The browser window didn't change at all.

Equally importantly, when I dragged the Preview window only 45% of the way over to the Cinema display, so it was still rendering using the laptop display profile, it looked the same (oversaturated) as the browser's rendering on the Cinema Display.

So what's happening here is that ColorSync isn't applying the correct display profile to the browser application windows on my secondary display. It's applying the display profiles for the default display, instead. This could either be an application bug (if it's the application's responsibility to put a call into the windows manager and/or ColorSync) or an OS bug (if the windows manager is supposed to handle this automatically and invisibly for all applications).

Either way, what it tells me is that most people are probably seeing my JPEG just fine. And if what they're seeing looks like a super-saturated version, they need to do what you suggested and set their most-commonly-used display for graphics as the default display.

This also makes it likely that some of the photographs I've posted previously are looking UNDER-saturated for most people, because I corrected a problem that didn't exist for them. Sigh, water under the bridge.

~ pax \ Ctein
[ Please excuse any word-salad. MacSpeech in training! ]
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-- Ctein's Online Gallery http://ctein.com 
-- Digital Restorations http://photo-repair.com 
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[Wirehead Arts]

I wrote some of my own thoughts on the subject recently: http://www.wireheadarts.com/blog/camera_that_does_everything/