Digital Zoom

Posted on 2003/09/18 13:22:43 (September 2003) by john.

What is the point?

A joint rant which started on the message board, and has sinced been moved here. We pick up the story with Rob having mentioned a video clip I'd made with my digital camera.

[John]
It is quite special though isn't it? I think that one little movie single-handedly justifies the video clip feature on my camera.

[Jimmy]
Actually, there is no justification for that feature whatsoever. Digital cameras should decide whether they take movies or stills, and do just one of those. Otherwise we all end up paying through the nose for silly features we hardly ever use ... while the main purpose of the device is compromised e.g. poor colour quality.

[John]
I actually agree with you to some extent on this. Although I would lay the blame more squarely at the feet of people with ORD (obsessive resolution disorder). As in, the people who think the only way to measure the quality of a digital camera is its megapixel rating.

I'm on my third camera now, they're all from the same manufacturer (Sanyo), and each of them was more or less the latest model when I bought it. So, I'd assumed they'd all be an unpwards progression - each camera would be basically the same as the last but slightly better in some way. In fact, the current camera, number three, often takes worse pictures in certain situations than the second one would have done. The reason? Sanyo seems to have sold out at some point between camera two and three, and gone for the low quality (therefore cheap) but higher resolution CCD rather than the high quality (therefore expensive) but lower resolution one, to remain competitive. This is because, as I said, resolution is the only thing most people seem to judge digital cameras on, and for it's price range Sanyo's cameras were normally ignored by the general public for being too low resolution.

I doubt this is an isolated incident - the obsession with megapixels (and perhaps, as Jimmy says, pointless features we don't really need) is going to mean we're all going to end up with worse digital cameras.

[Jimmy]
Indeed. The thing to *really* look out for is the physical size of the CCD chip. The smaller the chip, the fewer photons fall on each pixel, and hence the greater amplification required. The amplification is analogue and prone to noise ... so for the best results you want the largest possible capture-device. Of course, resolution-reduction will also help out here. Beyond about 3 MPixels, you can't really tell the difference in quality anyway ... it's gonna be approximately as good as 35mm film. And another thing ... I want a zoom-lense. Yeah, one of those big, bolt-on jobbies about 8 inches long. How many times have you taken a picture of something which looks amazing ... only to find it lost ina borind background? Digital zoom, of course, is no zoom at all ... just pixellation, so bollocks to it.

[John]
Yes, I've always wondered what the point of digital zoom is, given that it's basically the same as taking a picture at the highest possible resolution and then cropping the bit you want afterwards. I guess the only benefit of it is that it saves you a bit of space on your card. I can edit images on the camera itself with mine, which includes cropping, and I'd be quite happy to just have this feature rather than a digital zoom. Besides anything else, you're probably more likely to frame your subject better after the event anyway.

Having said all of that, it is vaguely useful when doing video clips, as these are restricted to a resolution much lower than the maximum resolution of the camera. So here it makes a bit of sense to have a digital zoom. Although, of course, it isn't a zoom at all really - what it really means is "which area of the CCD do you want to record?".

Or are you talking about a digital zoom which resizes the bitmap in the firmware? Now that sounds particularly horrid. On my camera I can only use digital zoom on the lower resolutions, which brought me to the assumption it was basically a crop. Resizing in firmware though... -shudder-.

Similarly, a lot of cameras nowadays (mine included) seem to have a maximum resolution you can take pictures at which is actually above the maximum resolution of the CCD - apparently it interpolates into the higher resolution. What is the point of this? Can this ever be any better than taking a picture at the CCD's maximum resolution and then resizing it on your PC (which is also pointless)? I think not somehow. The more I think about it, the more it makes me wonder if we're being led up the garden path by these digital camera manufacturers.

[Jimmy]
Up the garden path, in through the French windows at the back of the house, out again at the front door, down the drive, across the road, round the corner, and into the park for a game of frizbee. That's where we've been led, mate. My camere offers "Digital zoom up to 4x" at the maximum resolution. This *must* mave some sort of in-camera StretchBlt going on. As I said before, "Bollocks to it".

Here's some image to illustrate the point, as Jimmy puts it the second one might just have well been enlarged from the first one on the PC.

So what, exactly, can we *do* about this? Is there a "Know good camera" which we can all buy, without paying too much?

Posted by Jimmy at 2003/09/18 14:09:26.

dpreview.com seems to be quite widely respected for giving fair reviews... However as one might expect, it doesn't just downright tell you to go out and buy camera X.

Posted by John at 2003/09/18 14:10:29.

What it really comes down to is, when I take a picture of something, I want it to look like how it actually looked to me at the time. I get the impression in photography terms this is asking for the moon on a stick - our eyes are a downright fantastic bit of photographic equipment. Cameras, generally, are not.
It would be nice if there was some way a camera could behave adaptively and sort of learn how you want your pictures to look as it went along. So, assuming the preview screen actually gave you a faithful impression of what the end result was going to be, you could give it a series of hints until it got it right. Like, no, the whole thing's too dark - that bit is out of focus, that bit is blurred, this area is washed out, that thing over there is the wrong colour, and so on.
To an extent, we all have slightly different eyesight, we all perceive colour differently, and we all have different expectations of pictures, and interests in different parts of them. So it would be nice to have a camera that sort of moulded itself to your own preferences like that.

Posted by John at 2003/09/18 14:27:46.

I think you've hit on something important there ... the fact that the picture always looks bloody marvellous on that preview screen. Why is that? On my camera, the sky is always washed-out, but on the preview-screen it always looks colourful and dramatic. How come?

Posted by Jimmy at 2003/09/18 15:13:42.

Actually, on mine, the preview screen is usually worse than the end result. Either way, it's not hugely useful for anything other than just composition if it doesn't accurately represent what the picture you take is going to look like.

Posted by John at 2003/09/18 15:54:58.

I just wish they'd get the "Essentials" right, before charging us for all the non-essential gadgetry. It's very hard to find a place which will sell you a decent camera. Sure, they'll all sell you an expensive one, but what does the bloke in the shop know? Sod all, that's how much.

Posted by Jimmy at 2003/09/18 16:50:20.

I totally agree about the digital zoom; it's utterly pointless. Useful on the odd occasion, taking photos at music festivals or doing macro work, but ultimately nothing more than a easy cropping service for those without photo editing skills. But I guess they've got to be accounted for.

I'm not too sure about the movie feature grudge though. If a camera's got the capacity to capture moving images then it must have a high capture rate. For me, the higher the capture rate the better. My Nikon'll grab six 2560 by 1920 images before it needs to pause for the data to be written. It's a wonderful thing (especially when doing arty stuff) but it relies on the tech designed for the movie capture. Admittedly i've only captured movies with it twice but it opens up other features on the camera.

Oh, but I hate preview screens; they're dirty little things which will lie to you at the most inopportune of moments. Lie and eat batteries. I'm all for the view finder though although after playing with a FujiS2 Pro I must own a digital SLR. My Nikon's great but it's just a pretend SLR. I want to actually 'see' what i'm taking a photo of, not a squished up representation of it.

Posted by Rusty at 2003/09/18 17:59:09.

I have just brought a Fuji Film F401 Zoom, and while i agree that the zoom feature is pretty pointless, i have to say that the rest of the camera is blooming marvellous. There is a vid dip feature - which is fun. It also doesn't really cut down the number of pics i can take after takilng 1mins film- can still get well over 70, and how often am i likely to take more than that without downloading?

Although i prefer to use the viewfinder due to the battery drain, the preview screen actually looks remarkably like the finished pic - and i have some really nice looking pisc of Lincoln at the mo.

I chose this camera coz the bloke in the shop said so. Ok, not usually a good idea, knowing how useless most electrical shop morons are. However this one knew his stuff, and was buying the same camera. He even told me to wait 2 days until the price went down. I payed nearly 100 pounds less because of this. (On special offer, not reduction - so it is still worth more than i payed for it... yay.
I am very happy with my new camera.

Posted by Crystal at 2003/09/19 09:33:29.

So what you want (Jimmy in particular) is the Canon EOS-300D. That'd be the lowest priced Digital-SLR ever. It's not perfect, by any means, but it does accept proper SLR lenses as found on the analogue EOS series cameras. Yes, ladies and gentlefolk, proper zoom.

Of course, as it's a CCD in the end, with traditional lenses you only use the central part of the lens. Canon has also released a bunch of didital specific lenses (well, two so far) which are designed specifically for digital.

Still suffers when the flash is being used though. That's the biggest problem with digicams in my opinion.

Posted by Simon at 2003/09/19 13:31:29.

Oh, I should mention that lowest price doesn't necessarily equate with *cheap*. It's somewhere in the region of 900 nicker RRP. Ian at Softel has one on order, so we can see how good it is when it eventually arrives!

Posted by Simon at 2003/09/19 13:32:49.

It's interesting that those didital (I presume you mean digital) specific lenses are designed specifically for digital. I wonder how this crazy set of circumstances may have come about.

Posted by John at 2003/09/19 13:36:34.

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