Canon PowerShot Pro90 IS Review
Timings & File Sizes
Timing Notes: All times calculated as an average of three operations. Unless otherwise stated all timings were made on a 1856 x 1392 JPEG image @ FINE compression (around 560 KB per image).
File Size Notes: All file sizes are an average of three files. As is the case with JPEG it's difficult to predict the size of an image because it will vary a fair amount depending on the content of the image (especially the amount of detail captured). For example, take a photograph of a fairly empty wall and you'll get a small JPEG, take a photograph of a bush with a lot of detail and you'll get a larger image. File sizes here are closer to the later, the larger size of file you should expect.
As we found on the G1 the Pro90 also isn't the fastest starter, and it also was slower at starting using a Microdrive than a normal Flash Memory CF card. I can only put this down to the latency of the camera recognising the Microdrive or the time it takes the Microdrive to spin up. It's a pity though because that makes the Pro90 a fairly slow starter (though quicker than the G1) with a Microdrive. Here's the breakdown of timing switching from Off to Record in "P" exposure mode (LCD open):
|Time *F (seconds)||Time *I (seconds)||Activity|
|0||0||Switch turned from Off to Record|
|2.5||4.5||Top LCD comes on|
|4.7||6.1||Rear LCD/EVF comes on, camera ready|
*I 1 GB IBM Microdrive, *F 128 MB Delkin Flash
Symbols: ~ = roughly / approximately.
|OFF to REC *I||6.1||(Detailed above)|
|OFF to PLAY *I||4.7||Busy appears, image about 1 sec later|
OFF to REC *F
|OFF to PLAY *F||2.3||Busy appears, image about 1 sec later|
|REC to OFF||1.3||Lens parks internally about 1 sec later|
|PLAY to OFF||1.4||Lens parks internally about 1 sec later|
|REC to PLAY||2.4||Image is displayed|
|PLAY to REC||3.1|
|PLAY: Image to Image||~0.7|
|PLAY: INDEX thumbnail view||1.5||Full page of 9 thumbnails displayed|
|Auto Focus LAG||0.8 - 2.0||Dependent on focus subject *|
|AE-L metering (press *)||<0.5||Very, very fast|
|Shutter Release LAG||<0.1||Very fast, just as fast as G1 *|
|Total LAG||1.1||No pre-focus, one complete press *|
|OFF to SHOT TAKEN *I||7.7||Switch on + Press shutter release|
|OFF to SHOT TAKEN *F||5.5||Switch on + Press shutter release|
*I 1 GB IBM Microdrive, *F 128 MB Delkin Flash
* LAG times are often misunderstood and so are described below:
Auto Focus LAG is (roughly) the amount of time it takes the camera to autofocus (a half-press and hold of the shutter release button), this timing is normally the most variable as its affected by the subject matter, current focus position, still or moving subject etc. This timing is an average.
Shutter Release LAG is the amount of time it takes to take the shot after autofocus, this timing assumes you have already focused (half-pressed the shutter release) and now press the shutter release button all the way down to take the shot. This timing is an average.
Total LAG is the total time it takes (not just the two above added together) if you haven't pre-focused, that is no finger touching the shutter release button, press it all the way down in one movement, this new timing is how long it'd take if you were in one of those spur-of-the-moment situations. This timing is an average.
The Pro90 is indeed faster than the G1 at startup (thanks primarily to a non-extending lens), shutter release lag is just as fast which means as long as you've pre-focused (half-pressed the shutter release or manually focused) the Pro90 will shoot almost at the instant you press the shutter release). However, autofocus does appear to be slower by a fraction of a second.
File Flush Timing
Timings shown below are the time taken for the camera to "flush" the image out to the CF card (when the green CF activity light stops flashing). The estimated number of images per 16 MB CompactFlash card is given as a guide to beginners (as that's what's bundled with the camera - differs with region).
16 MB CF card
|Store 1856 x 1392 RAW||7.5||6.3||~1,900 KB||8|
|Store 1856 x 1392 Super-Fine||5.4||4.3||~1,100 KB||14|
|Store 1856 x 1392 Fine||4.0||3.1||~560 KB||28|
|Store 1856 x 1392 Standard||3.2||2.5||~250 KB||64|
|Store 1024 x 768 Super-Fine||-||2.7||~480 KB||31|
|Store 1024 x 768 Fine||-||2.1||~220 KB||68|
|Store 1024 x 768 Standard||-||1.5||~100 KB||150|
|Store 640 x 480 Super-Fine||-||1.5||~190 KB||78|
|Store 640 x 480 Fine||-||1.5||~80 KB||187|
|Store 640 x 480 Standard||-||1.5||~60 KB||250|
*I 1 GB IBM Microdrive, *F 128 MB Delkin Flash, ** Approx., exact numbers will vary
As we've seen with other digital cameras it's worth noting how much longer it takes to write images out to an IBM Microdrive compared to a flash memory card.
The table below shows the results of our continuous shooting test, indicating the actual frame rate along with maximum number of frames at a selection of image resolution / quality settings and how long you would have to wait after taking the maximum number of frames before you could take the next shot.
|Image Type||Frames per sec
|Max no. of frames||
|1856 x 1392 RAW||0.5||4||6.0 secs|
|1856 x 1392 Super-Fine||0.6||5||5.5 secs|
|1856 x 1392 Fine||0.6||8||3.7 secs|
|1856 x 1392 Standard||0.6||15||3.7 secs|
|1024 x 768 Fine||0.7||25||3.7 secs|
As you can see the Pro90 is pretty slow in continuous mode, not even managing a single frame per second. I would put this down to the permanent noise reduction carried out on ALL Pro90 images. It would have been nice of Canon to allow us to disable this noise reduction filter so as to get the most out of continuous shooting.
Again, Canon have used the excellent BP-511 battery pack (rated as 7.4 V, 1100 mAh, 8 Wh), originally designed for much hungrier products such as DV cameras it's no surprise that on a single charge this battery seems to just last and last... Note that this is the same battery used on the G1 and EOS-D30.