Canon a640 vs a650IS

Hi,

I'm new to diving, and I plan to buy a camera for capturing underwater photos.

Because of the existance of reasonable priced underwater cases, I've checked some Canon consumer cameras, and I've come to choose between A640 and A650IS, but I have difficulties to choose between the two.

Basically, the 2 cameras functions being almost identical, my concern issues (that can have influence underwater) were:

1) - dimensions: a650 is bulkier than a640;

2) - high ISO capability: is seems that a650 delivers less noise at ISO800 than a640. My question for those who was experience is what typical ISO setting do you use underwater ?

3) - movie mode: my assumption would be that both camera delivers the same movie quality; maybe a slight advantage for the a650IS which can shot films with IS enabled;

4) 6x optical zoom is really an advantage underwater over the 4x of the a640 ?

Not forget that a640 is almost 100$ less priced than the a650IS, and also the case for a650 seems to be slightly more expensive.

I'm also interested if the underwater cases from Canon (WP-DC8 or WP-DC18) allow the attachment of flash, wide or macro lenses (internal or external).

Thanks and Regards

Doru

Doru,

I think you would enjoy the IS for top side. photography; the IS feature is of little or no use underwater. The focal length of the A650 is not optimal for u/w shots: 7.4-44.4mm f/2.8-4.8 (35mm film equivalent: 35-210mm). I suggest you will want a wide angle adaptor to adjust the focal length to arround 15 to 18 mm (35 equ.) on the wide end.

In general, the lower the ISO the better. If you are not using an external strobe, depending on the water clarity and depth, ISO 80, 100, or 200 or maybe 400. I recomend not using the built in flash (tons of backscatter).

Ok, so this wide angle is the same problem for both a640 and a650 (35mm).

But do you know if the canon underwater case (DC8 or DC18) allows to attach to the camera the wide angle adaptor ?

I'm talking about the one that it is attached directly to the camera (inside the case), although it would be interesting to know if an external one can be attached to the case.

Regards,

Doru

Ok, so this wide angle is the same problem for both a640 and a650 (35mm).

 

But do you know if the canon underwater case (DC8 or DC18) allows to attach to the camera the wide angle adaptor ?

I'm talking about the one that it is attached directly to the camera (inside the case), although it would be interesting to know if an external one can be attached to the case.

 

Regards,

Doru

the A640 housing (DC8) does not allow any add on lenses - it's an oval port. I'd suggest getting the Ikelite housing which does allow add on ports. I think it is the same for the A650is housing, and also the G9..

Z...