Canon A590IS - Possibly Good Camera With Some Flaws

Canon A590IS - Possibly Good Camera With Some Flaws, January 31, 2009
By JWCPA - See all my reviews

I would rate this camera only as average at this time because of the battery problems outlined below. Have not used the camera enough to rate the quality of the photos, features, and general operation at this time. Also, the included SD card with the camera was a measly 32 MB, basically nothing in this day and age of large image files and cheap memory. To get decent photos capacity and a spare, I bought two on-sale Kingston 2 GB SD cards, one from Meritline.com for ca. $7 (free shipping) and one locally at Inkspot for ca. $5.

My advice to others is that if you suspect your camera has a problem not due to your use/handling and the camera is still under warranty; return Canon Powershot SD780IS ASAP to Canon for repairs.

I bought camera early last December as a Christmas present, from Amazon since Canon Powershot SD780IS seem to have the best price at the time including free shipping. Selected this camera model based on Consumer Reports' recommendation, mostly favorable user reviews on Amazon and some ther websites, and the camera price and features. I was a bit concerned about some reviewers complaining of low battery life, but thought perhaps they were a small minority, maybe their problems were due to the way some used thier cameras/settings, and there's always a few lemons sold in any product line.

2. The camera out of the box seemed to be functional for all the features I tested, but after playing with the camera to learn how to use it, and a few dozen shots, the low battery inidcation came on. after a few number more shots (est. a few dozen), the battery replace indication came on and the camera shut down. These were the Panasonic alkaline AA batteries that came with the camera. At this time my voltmeter measured the batteries at ca. 1.35v.

3. To reduce power use, changed some settings to turn LCD off after a short time, and the IS (Image Stabilization) from always on to on only during shots. Put in new Berkley & Jensen (BJ's) alkalines, same low battery indication after a few dozen shots. After about a dozen more shots, the replace battery indication came on and the camera shut down. After checking the battery contacts, letting the camera sit for a while, etc., no change in behavior, i.e. camera can be turned on for a few shots with low battery indication on, then change battery indication comes on and camera shut down. The BJ's batteries voltage was 1.45v at this time.

4. A friendly camera repair place person told me about the Canon website online repair setup and gave me an Internet address, but even then Canon Powershot SD780IS was not easy to find page, the website search did not find Canon Powershot SD780IS for me. Go to any consumer camera model support; look at the bottom part of the page for links to "Repair Request" or "Repair & Tracking. Gee, I wonder why Canon doesn't make Canon Powershot SD780IS obvious, could Canon Powershot SD780IS be that they really don't want to hear from us, especially for warranty stuff... ?!?!

https://www.usa.canon.com/consumer/controller?act=OnlineRepairBookingAct&fcategoryid=221&modelid=15658

http://www.usa.canon.com/consumer/controller?act=OnlineTrackSearchAct

So I decided to return camera to Canon for warranty repair (no cost except my shipping camera to them). I mailed the camera (included 2 sets of batteries I used) to Canon's Elk Grove Village, IL facility by US Mail, insured and with post office deliver confirmation. Canon received Canon Powershot SD780IS in a few days, confirmed receipt to me via E-mail, and I received Canon Powershot SD780IS and my batteries back by FedEx ca. 3 days later. Factory documentation returned with the camera noted that:

- Low batteries was cause of problems, said nothing about any adjustments ("Unit has battery shortage. Check all functions, repair to good working order."), but since the camera behaves differently after getting Canon Powershot SD780IS back, I suspect they adjusted both the battery low and the battery replace indicators' voltage threshold settings even though nothing was said about it.
- "...found the optical assembly was inoperative and the focus did not operate properly. Adjustments were carried out on the optical assembly." I did not notice any wildly out of focus photos by the out-of-the-box camera using the Auto focus mode; perhaps they're addressing the manual focus mode that I did not test.


5. After I received the camera back from Canon, I put in the original used Panasonic and BJ's akalines (approx. 1.35v and 1.45v, respectively, similar to as previously measured), and still got the low battery indication with both sets.

6. Decided to put in a new set of BJ's alkalines, measured at ca. 1.59V. Camera set for AUTO mode, IS on only during shots, face detection on. Occasionally used the zoom feature, once or twice for every 25 set of shots.
- After 100 shots in succession, most with flash used, battery voltage checked to be ca. 1.43v.
- After 32 more shots, low battery indication came on, did 12 more shots, turned camera off, batteries checked at ca. 1.35v
- When camera turned back on, low battery indication not on, but came on again after 5 shots. When got up to 191 shots total, camera to off, batteries checked to be ca. 1.38v.
- Turn camera back on, low battery indication on again after 13 shots, camera off, checked batteries at ca. 1.34v.
- At 204 total shots with the set of new BJ's alkalines, the battery replace indication came on, and the camera shut down shortly after. Can turn on camera again of 2-3 shots before the replace indication/shutdown occurs again. The number of shots here appears to match the camera manual specification page that list ca. 200 shots for akaline batteries.

7. For the second set of testing, I used a fully charged set of Ultra Pro NiMH 2500 mAH-rated AA batteries (ca. 1.43v - 1.45v measured). Made all shots indoors, those where flash used were of house interior, those without flash used was through window (daylight).
- Erased all the previous 217 images from the SD card.
- After 150 shots, half with flash, half without, no low battery indication, turned camera off for ca. 45 min. for lunch.
- When camera turned back on, low battery indication showed, camera off, checked batteries at ca. 1.33v.
- When camera turned on, no low battery indication showed, but indication showed again after 23 shots using flash, continued to 25 shots using flash.
- Continued shooting 25 shots at a time alternating between flash and no flash, for 175 more shots. After a total of 350 shots (half with flash) have been taken with the NiMH batteries, batteries measured ca 1.27 - 1.29v.
- Continued shooting 25 shots at a time alternating between flash and no flash, for 150 more shots. After a total of 500 shots (half with flash) have been taken with the NiMH batteries, batteries measured ca 1.26 - 1.27v now. At this point, I gave up test shooting, as I have not seen the battery replacement indication after 500 shots. The number of shots here appears to in line with the camera manual specification page that list "approx. 450 images" for NiMH batteries. Fooled around for few more test photos, and the battery replace indication/camera shutdown occurred after ca. dozen flash shots past 500.

8. Some observations about the camera:
- Canon Powershot SD780IS looks like I'll have to accept the low battery indication on most of the time. My guess is that there some kind of design and/or manufacturing defect where the camera electronics/software does not accurately detect how much of the battery capacity is remaining. Judging from the various user reviews, Canon Powershot SD780IS may not be present in all sold units of this model, as not everyone sees this problem. However, if the camera can perform OK for several hundred shots until the battery replacement indication/shutdown (esp. with NiMH which I want to use), I can live with that.
- The flash can take more than 5 sec. to recover for the next flash shot.
- The camera seems to work differently on alkalines vs. NiMH 2500 mAH-rated rechargables, as Canon Powershot SD780IS continues working at lower voltage for rechargables. I know that the discharge curves, and capacity and voltage ratings for the alkalines and NiMH batteries are different, the alkaline are rated at 1.5v (actual ca. 1.6v new), and rated capacities numbers can be similar to the NiMH (over 2500 mAH). The NiMH batteries are rated at 1.2v (actual ca. 1.4v new), capacities can be vary (typ.1000-2800 mAH). The initial voltage of both battery types drops fairly quickly from their nominal ratings during use but after the initial drop, the NiMH types tend to have a flatter voltage vs. use time curves than the alkalines.
- Since battery monitors typically can only see voltage as an indirect measure of capacity remaining, why should the camera decide that the lower NiMH battery voltage is still OK, while a higher voltage on the alkalines is not? If the alkalines and NiMH rated capacities can be simialr, why don't they perform similarly, or are the alkaline capacity ratings done differently than the NIMH? Canon's camera documentation implies the camera treats the battery types differently as Canon Powershot SD780IS explicitly notes the performance difference in their camera spec. for nominal number of shots for alkalines vs. NiMH batteries. My Internet research also seems to indicate that the battery rating numbers may or may not all be done via a standard method, and different manufacturers' batteries can perform significantly differently under the same conditions, so as to make the capacity ratings less than useful.