James O'Neill's blog

Windows Platform, Virtualization and PowerShell with a little Photography for good measure.

So long Compact flash: a new camera

So long Compact flash: a new camera

  • Comments 3
  • Likes

It's amazing to see a technology to go from "new"to "Obsolete" in half a dozen years. I remember buying an IBM Microdrive in 2001 - a power hungry and rather unreliable device it was, the jacket for my iPAQ would take CF type II cards. A year later my first digital compact camera took CF but only Type I so I spent £70 on a 64MB card. (Today I can buy four cards, 4GB in capacity for that)  In 2003 first digital SLR also took CF. Both cameras came from Pentax; I loved the SLR but was indifferent to the compact. Pentax have gone totally SD since, so my updated SLR takes SD cards, my last 3 phones have used SD or a derivative of it. My previous laptop had SD support and I've added SD support to the Dell. Since the secondhand value for the compact was close to zero I put it in a scuba housing. But it wasn't great. Its short-life proprietary batteries mean I have to take a charger and a second battery on dive trips. The Screen is small, the shutter lag dreadful.

I began to cast around for a new camera and the newer Pentax models don't have dive housings; which meant changing brands: no great loss in compacts. My requirements didn't seem so very tough.

  • Dive housing available
  • AA Batteries
  • SD Memory

I didn't have any megapixel requirement -I'll repeat something I've said before more megapixels means the image formed by the lens is recorded with greater fidelity. The lenses on most compacts don't justify the pixels the marketing folk won't the put behind them.  I wanted a shorter shutter lag -but what we put up with in 2002 wouldn't sell today. A bigger LCD seems to be standard too -that makes things easier underwater.  

The list shrank pretty quickly. This brand uses proprietary batteries. That brand used memory stick. These other Brands didn't have dive housings. But Canon's Powershot A570IS ticked all the boxes, with the bonus of a dedicated Underwater mode and Image stabilization. I've been robust about Canon FUD that in-body stabilization doesn't work, it does. Canon SLRs just don't feel right in my hands; brand loyalty to Pentax isn't absolute, but it's stronger than any Brand antipathy I have for Canon. As it was, over the bank holiday weekend Canon were running a £50 cash-back promotion, a bit of checking found that the camera - (list price £220) could be shipped to my door for £140 - £90 after the cash back. Decision made.

It's amazing to see how compacts have come on in 5 years.

  2002: Pentax Optio 430RS 2007 Canon Powesrhot A570IS
Cost ~ £400 ( List price £600) ~ £100 (List price £220)
Display 1 sq inch (1.2 x 9: diagonal 1.5") 3 sq inch (2.0 x 1.5 diagonal 2.5")
Shutter Lag Intrusively slow Tolerably slow
USB 1.0 requires driver (mini-b connector) 2.0 plug and play (mini-b connector)
Apperture f/2.6 or f/5 (wide)
f/4.8 or f/9.2(tele)
f/2.6 - f/8 in 1/3 stop steps (wide)
f/5.5 - f/8 (tele)
Zoom range 3x in 6 steps  (38-113mm equivalent on 7.2 x 5.3 mm sensor) 4x  in 7 steps(35-140mm equivalent on 5.8x4.3mm sensor).
Megapixels 4 7
ISO 100,200 80,100,200,400,800,1600
Video 320x240 14 fps (Mute) 640x480 30fps with (surprisingly good) sound
Other   Image stabilization, Facial recognition auto-focus,Voice notes, underwater mode,  Rule of thirds grid, stitch assist mode, Red eye removal

As I said I don't see the greater pixel count as giving me higher resolution pictures. The Canon's imaging chip is only 2/3 the size of the Pentax's one, I doubt if it's lens is any better - but to give those pixels the same amount of detail to digitize it needs be much better. It's capturing an inferior image with greater fidelity.  More pixels in a smaller area and higher ISO rating mean Canon need to be aggressive with noise reduction, which reduces detail.

When I care about quality I've got my SLR, with a couple of fantastic Pentax prime lenses. The new compact's job is to get pictures that the old one missed, in places where the SLR won't go. And I'm happy it will do that.

Comments
  • You say "More pixels in a smaller area and higher ISO rating and higher ISO rating mean Canon need to be aggressive with noise reduction".

    I'm also not sure I follow your logic about sensor size.  I'd have said that, all other things being equal, the same amount of light falls on the sensor, regardless of its size.  Visualize the cone of light coming from the lens -- if you replace the sensor with one 2/3 the size, you'd put it closer to the lens not keep it where the old one was.   Thus, it doesn't need to be *much* better at all, it just needs to get the same performance out of CCD elements that are 2/3 the size. In five years of advances, it is quite reasonable to assume that that is quite possible.  

    Also, although I don't follow these things closely, but I seem to recall that Canon is one of the least aggressive brands w.r.t. noise reduction. Obviously, high ISO settings will be grainy, but then so is high-ISO film.

    I don't see a review on my usual source, dpreview.com, but dcresource writes:

    "The PowerShot A570 has the kind of image quality one expects from Canon: very good. It took well-exposed photos, with accurate, saturated colors. Photos have a smooth look to them which is more common [for] digital SLRs than compact point-and-shoots. As the tests above showed, noise levels in good lighting are quite low, even at ISO 400. Purple fringing was minimal."

    In other words, no actual problems.

    Anyway, it sounds like a nice enough Camera to me, so congratuations on buying it -- even if you do seem to think it's only good enough to be your back-up/risk-zone camera.

    Have fun on your next dive...

  • If the pixels are smaller (and more Pixels in a smaller area means they are) less light falls on each one.

    If the sensor is smaller you DO move it closer to the lens. However the lens apperture is expressed as size of the hole relative to focal length, hence "f over ...".  So an f/4 lens will deliver the same amount of light to a tiny digital sensor or a 10x8 plate camera: with ISO 100 film and the lens at f/4 uses the same shutter speed as a digi set to ISO 100 and its lens at f/4

    If the Pixels are smaller the voltage you get for the light arriving is smaller. (Unless you can increase what sensor makers call quantum efficiancy). Getting high ISO means turning up the gain, and that means more intrusive noise. New sensors are more efficiant, and do have lower background noise, but as someone once said "you cannye change the laws of physics".

    Getting decent output from them at high ISO depends on NR, and it has to be pretty agressive. Whether canon are a bit more or a bit less agressive than the others I can't say. That was meant to be {The manufacturer} not Canon-in-particular.

    The test shots I've done show that *if I pixel peep* I can find noise reduction artifacts even at low ISO. And as Dcresource is right that the picures looked smooth with low noise. That smoothness is actually a loss of detail: but there is more than enough detail in these shots for any size print I'm likely to want from this camera. It's not just a "Risk zone" camera. It's also the "I need a small camera to take on this trip" camera. And my SLR isn't just "I need the last drop of quality and or interchangable lenses". A compact is a better proposition underwater - power zoom and LCD viewfinder see to that. If someone gave me the SLR  housing (and insurance against flooding) I still would prefer a compact.

    The point was really that you can't sell a 4MP camera any more - but the thing that makes a modern 7MP camera ISN'T the greater number of pixels. It's everything else. The same is true of my new SLR. The fact it has 10MP and the old one had 6 is the least significant improvement. In both cases the cameras are a lot better - the technical quality of the image they make is only a small part of that - the important question on a camera is "Will this camera help me get more pictures which are good", not "Will this camera improve the resolution of my images".

     

  • **Warning** Neither I nor Microsoft will take any responsibility for what happens if you follow these

Your comment has been posted.   Close
Thank you, your comment requires moderation so it may take a while to appear.   Close
Leave a Comment