joelh47

Have you tried anything with the lens off the camera and no CF card in the slot? If you regain access to your menus and other functions with these both removed, you can put them back one at a time to see which one is causing the problem. If the lens, CF card and battery are all OK, and you don't have a stuck button somewhere, you will probably have to take or send the camera in for repair.

 

I had a lens once that was hanging up my camera after taking a picture. The mirror would flip up, the shutter would fire, then nothing else, just a blank view finder until I started to dismount the lens or turn the camera off and back on. I also once had a bad CF card (though on a G5, not a DSLR) hang up the camera. One last camera hangup I experienced was the FEL button somehow stuck in on a film camera. The focus LED's and metering info stayed on continuously, and I thought something was seriously wrong until I inadvertently wiggled the FEL button and everything returned to normal.

I primarily use FTM when I need to pre-focus on something that is initially way out of focus. A severely out-of-focus subject, especially one that is low contrast, may be difficult for auto-focus to lock onto until it is brought somewhat into focus with the manual override. Then I engage the autofocus normally. Also, since I usually use Custom Function 4 to make the * button on the back of the camera activate autofocus, I am free to fine tune the focus manually if I need to without having to switch back and forth between manual and auto focus. Note that most of the photography I do is landscape and macro, so this method may not be appropriate for everyone.

Thanks to everyone for information on this. Bob's advice is probably the best - "If Canon say don't do it, don't do it!" (Except maybe for sensor cleaning, I think.) John's information about Lithium battery voltage was right on the money. I decided to buy a set of Energizer Lithium AA's just to satisfy my need for a quantitative answer on this, and all four cells were 1.8 +/- .01 volts. While at it, I checked the no-load voltage on Alkalines and NiMH cells, as well as a fully charged Canon BP511A. Here are the results:

 

Single cell Volts:

Lithium AA -- 1.80,

Alkaline AA -- 1.62,

NiMH AA -- 1.37,

 

Volts/6 AA Cells(Number used in BG-E2):

Lithium AA -- 10.80,

Alkaline AA -- 9.72,

NiMH AA -- 8.22

 

Single BP511A -- 8.36

 

With the voltage from six Lithium cells being more than a volt higher than that for Alkalines and almost 2.5 volts higher than a BP511A, I can now understand why Canon doesn't recommend using Lithium's in the BG-E2 grip. That said, however, it would be fairly easy to modify the BGM-E2 magazine to use five cells instead of six. Then the voltage would be a much more reasonable 9 volts. Of course that would probably void any Canon warranty for either the grip or the camera, so I don't expect to try that any time soon.

 

Joel Holcomb

I recently purchased a BG-E2 grip for my Canon 30D, and had hoped to use AA

Lithium batteries with it as a backup to the BP511A's because of their low

temperature capabilities in our cold Maine winters. However, the instructions

that come with the grip say to not use Lithium AA's because "Lithium batteries

do not operate with this camera." Trying to get some clarification of this, I

contacted Canon's tech support, and their response was "Because Canon does not

manufacture single use lithium batteries they may exceed the peak power needed

for the grip or camera and thus should not be used." However, since the

nominal voltage of AA size alkaline batteries (1.5 volts), which they do

recommend, is the same as for Lithium AA's, I couldn't see an obvious

technical reason why this would be so. So I was wondering if anyone had

actually used them successfully with the BG-E2/30D combination, or if anyone

knows a specific reason why they shouldn't be used.

 

I am an electronics technician by profession, so I understand that the

internal resistance of a power source can affect the current through a load

(the camera in this case) for a given voltage. This is why some power sources

perform better under load than others. The thing is, I am not really familiar

with the load characteristics of Lithium vs. Alkaline AA batteries. If anyone

who is can give me a better explanation than Canon did, or can confirm my

theory about Lithium batteries being able to supply more current under the

load of a 30D camera, then I would appreciate hearing from them.

 

Joel Holcomb