Canon A610

Started Jul 3, 2006 | Discussions thread
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VT
VT
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Canon A610
Jul 3, 2006

I realize this is now an older camera even though it's still listed on Canon's web site.

However I got this refurbished 5mp Canon A610 as a replacement for my ill fated Canon A70 with CCD problem - please see this thread for details -

More CCD/LCD problems (with A70)

http://forums.dpreview.com/forums/read.asp?forum=1010&message=18061084

I took shots of my "test" tree to compare the 5mp A610 performance against my
7mp Canon S70
http://forums.dpreview.com/forums/read.asp?forum=1010&message=14084087

Here's the full-frame shot of the tree -

the lens on the S70 was zoomed fully to the 100mm equivalent.
The red box is the area I examined.

For the A610 shots I had to zoom the lens less since the fully zoomed (max) position would have been an equivalant of 140mm.

I used trial and error to get my framing as close to the S70 shot as possible.

I took the shots within minutes of each other - however there was enough time lag between the S70 ISO50 SuperFine shot to make a difference in the lighting. However I think the side-by-side comparison shots are still valid.

If one looks carefully at these crops - the A610 shots look surprisingly sharp and one might even say they looked sharper than the very good S70 shots.......

In fact in comparison the S70 shots look kind of mushy/soft!!!

The comparison above does not emphasize this enough - so I pick another crop which was above and adjacent to the first crop (there is a bit of overlap) where the better lit pine needles show this phenomenon much better.

here's the comparison both crops UNretouched

The A610 looks much sharper to my eyes.

Note: there is NO movement in the S70 shots - I have lots of shots that I compared to and they all look the same (similarly my A610 shots all looked the same under close examination).

However if I were to enhance the S70 crop (some increase in contrast, and add a bit of saturation) then sharpened - slightly more than I do normally - the shots then start to look at least somewhat comparable -

I thought it was interesting on simply eye-balling the 100% shots on the screen the A610 shot(s) actually looked crisper than the S70 - which in comparsion almost looked mushy.....

Because of this I also took some shots of an old Paterson resolution test chart to directly compare the 5mp A610 and the 7mp S70

One can just make out the S70 resolved clearly up to the 30 cycles mark on the vertical bars - with the 33 cycles somewhat resolved but not clear. We probably can call it at about 31.5cycles.

The A610 being smaller is harder to make out - one has to count the cycle markers to get to where the vertical bars managed to resolve I counted 8 sections for good resolution - that's to 24 cycles on the chart, with perhaps up to the 27 cycles (but it was not clean) and maybe even 30 cycles section - so let's call it at 26cycles.

The comparison shows that the S70 was about 31.5/26 = 1.21 x the resolution of the 5mp A610 ie: = about 21% higher....

This shows 7mp S70 resolves a bit higher than the theoretical 19% over the 5mp A610 - but it's in the right ballpark.

Yet on the test tree shots the 5mp A610 shots viewed at 100% look quite a bit crisper than those from the 7mp S70......

I then thought perhaps the pine needles difference might be more to do with the color - ie: green, so rather than just comparing the white panel on the test chart - I examined more closely the green panel -

As can be seen the results were pretty similar - the S70 resolved cleanly up to the 30 cycles with some semblance of resolving at 33 cycles - so again I would "call it" at about 31-31.5 cycles.

The A610 again almost reached 27 cycles - it's just not really clean - whereas the 24 cycles is - however it has some semblance of resolving to almost 30 cycles - so again called at 26cycles.

So on the Green panel the resolution is still somewhere between 19-21% higher for the 7mp S70 over the 5mp A610 - which is the expected theoretical difference.

I think in the end it may be the image processing in the A610 - which tends toward a more sharpened and vivid image (yes, I did double check that the Function setting was at NO effects - ie: default normal setting)

Although looking at the side-by-side resolution chart panels both in White and Green the 7mp S70 looks marginally crisper to my eyes over the 5mp A610 - whereas the tree/pine needles shots the A610 looks way crisper......

so this remains a mystery to me.

Anyone with any suggestions?

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