[Timd]

With point & shoot and bridge cameras eating batteries, I would switch my camera on and off all the time, so much so that on one camera I had to have the switch replaced. With dSLR's (K200 and K5), I leave it on, sometimes overnight, with no discernible battery loss. In fact, with the camera off, inserting the SD card causes the memory light to flicker.

So, my two questions:
1) Is there any battery drain difference between having a Pentax dSLR switched on but in standby mode vs. switched off?
2) Is there any danger of changing lenses without switching the camera off? (Including SDM lenses).

Your comments and experience is appreciated.

Tim

[ZoeB]

There's no point in leaving it on constantly 24/7. Please, just switch it off at night. It may not drain battery, but it's just totally unnecessary. If you're so worried about a switch breaking that you're reluctant to use is at all, you might want to question the quality of the camera bodies that you're buying. And also, never ever ever ever take out a memory card with the camera on. That light flashing is the camera telling you that it's registered and mounted the SD card, and if it doesn't do that, it's cause for worry.

I've never been directly warned against changing lenses whilst the camera is on, but i almost always do, as much as anything else to use the startup sensor cleaning to get rid of any dust I may have knocked onto it while switching lenses.

[Giklab]

It's unnecessary to turn it off, I once left my D5000 on and three months later, the battery was still full. The stand-by mode is literally an auto-off.
SD card readers have a switch inside that is triggered if the card is inserted or removed. So the flicker is perfectly normal.

[dakight]

I can't say whether it makes a difference or not, but I always (unless I forget) turn it off when inserting or removing the memory card. I usually turn it off if I'm not planning to use the camera for a while but I don't necessarily turn it off when changing lenses. It would be unacceptably delicate if changing a lens could damage it or the body.

[severalsnakes]

The camera does "go to sleep", even if the switch is set to ON, so I wouldn't worry about too much battery drain.

I have been advised NOT to change lenses while the camera is on because there is some increased risk of dust accumulating on the sensor. Apparently the charge running through the sensor when the camera is on (and active) is enough to attract dust particles, moreso than when the camera is "off"... I don't know if this is true (I'm no camera scientist ) and I have most certainly (accidentally) changed lenses while the camera was on, so... good idea vs. totally vital? Somewhere in between?

[loco]

I don't know if there is a "correct" answer to this, but generally I leave my camera on when I'm using it and turn it off when I put it away. I do try to turn it off when changing lenses/memory cards, but occasionally I forget.

[sergysergy]

2) Is there any danger of changing lenses without switching the camera off? (Including SDM lenses).

People argue that the sensor might attract dust

[lytrytyr]

I have been advised NOT to change lenses while the camera is on because there is some increased risk of dust accumulating on the sensor. Apparently the charge running through the sensor when the camera is on (and active) is enough to attract dust particles, moreso than when the camera is "off"... I don't know if this is true (I'm no camera scientist ) and I have most certainly (accidentally) changed lenses while the camera was on, so... good idea vs. totally vital? Somewhere in between?

It's generally considered worthwhile:

How to Avoid a Dirty DSLR Image Sensor - Digital Photography School

[kh1234567890]

The camera does "go to sleep", even if the switch is set to ON, so I wouldn't worry about too much battery drain.?

But watch out (at least with my K-5ii) for leaving it with the card door open and no card inserted. This seems to drain the battery fast even with the camera in the 'sleep' mode.

[hjoseph7]

But watch out (at least with my K-5ii) for leaving it with the card door open and no card inserted. This seems to drain the battery fast even with the camera in the 'sleep' mode.

Another thing that drains the battery very quickly(at least on my K-5 Ii ) is leaving the camera connected to the computer after downloading pictures.

[Timd]

There's no point in leaving it on constantly 24/7. Please, just switch it off at night. It may not drain battery, but it's just totally unnecessary.

Let me state that this hasn't been deliberate. My leaving the camera on has been because I have not noticed any downside of doing so - in fact, it's much quicker to get that shot if the camera is on! I have sometimes forgotten to switch it off. I am happy the Pentax is more rugged than my old Fuji!

My experience is that I have seen no problem leaving the camera on for extended periods, even while changing the lens and the memory card. The memory card is the least of my worries as opening the door activates the switch. If there is a switch, then surely the designers would use it to make the card safe?

I don't buy the dust on sensor bit as it is behind the shutter and mirror: the sensor is only exposed when the mirror is up and the shutter activated. I hardly use live-view but would be interested if removing the lens while on live-view would close the shutter. I'm not that interested to risk my camera yet!

Thanks for your input. It's been interesting to see the reaction. I wish Pentax could be more specific on what is permitted / protected vs what is not advised.

[ZoeB]

Let me state that this hasn't been deliberate. My leaving the camera on has been because I have not noticed any downside of doing so - in fact, it's much quicker to get that shot if the camera is on! I have sometimes forgotten to switch it off. I am happy the Pentax is more rugged than my old Fuji!

My experience is that I have seen no problem leaving the camera on for extended periods, even while changing the lens and the memory card. The memory card is the least of my worries as opening the door activates the switch. If there is a switch, then surely the designers would use it to make the card safe?

I don't buy the dust on sensor bit as it is behind the shutter and mirror: the sensor is only exposed when the mirror is up and the shutter activated. I hardly use live-view but would be interested if removing the lens while on live-view would close the shutter. I'm not that interested to risk my camera yet!

Thanks for your input. It's been interesting to see the reaction. I wish Pentax could be more specific on what is permitted / protected vs what is not advised.

You'll be shocked at how easy it is to get dust on the sensor. My previous camera had neither live view nor mirror lock up shooting (that I knew of, anyway), but by the end of it's life, the sensor was so dusty that I'd get useless shots because of too much dust. The mirror and shutter are a barrier, yes, but they don't form a seal. Some dust on the sensor is inevitable, but doing certain things like shutting the camera off when changing lenses and pointing the body down while switching will help prevent too much buildup.
As for changing memory cards, you really should shut the camera off when taking a memory card out-- the camera unmounts it on shutoff, meaning that taking it out won't corrupt any data. It's the same as ejecting a memory stick or ipod from the computer, only you aren't able to do this while the camera is on.

[mrNewt]

Demystifying some things...

Is perfectly normal to leave the camera ON all the time. If your shutdown timer is enabled to a specific time, the camera will shutdown itself anyway no matter the position of the ON/OFF switch.
If the timer is disabled, then the only bad thing that will happen is for your battery to drain faster... just carry some extra in this case. And it makes perfect sense to disable the shutdown timer and keep the camera on when you need to have the camera ready at any moment and you need to be fast.

Is perfectly normal to change your lenses with the camera ON as well.
In DSLR case, mirror is down and shutter is closed so dust getting on the sensor is very improbable... unless you keep the camera towards a strong wind with sand and or water particles. But then that is bad to do even when the camera is off anyway.
In mirror-less cameras is slightly a different story. The cameras with built-in shutter will have the shutter open when the camera is on, but if you pay attention is should be OK as well because.... in the case of cameras with no built-in shutter, you change the lenses with a sensor exposed anyway (no matter if the camera is on or off) and I never heard of issues, as long you pay attention at what you are doing.

And here is a shocker... is absolutely nothing wrong with changing the cards in your camera while the camera is ON.
Your camera is like a computer, you can plug and unplug a memory card into a computer without shutting it down no? Same with the camera!
The only thing you have to pay attention is NOT to remove it while the camera is writing to card. That's it!

Any DON'Ts in these situations are nothing but scare stories...

[ZoeB]

Demystifying some things...

Is perfectly normal to leave the camera ON all the time. If your shutdown timer is enabled to a specific time, the camera will shutdown itself anyway no matter the position of the ON/OFF switch.
If the timer is disabled, then the only bad thing that will happen is for your battery to drain faster... just carry some extra in this case. And it makes perfect sense to disable the shutdown timer and keep the camera on when you need to have the camera ready at any moment and you need to be fast.

Is perfectly normal to change your lenses with the camera ON as well.
In DSLR case, mirror is down and shutter is closed so dust getting on the sensor is very improbable... unless you keep the camera towards a strong wind with sand and or water particles. But then that is bad to do even when the camera is off anyway.
In mirror-less cameras is slightly a different story. The cameras with built-in shutter will have the shutter open when the camera is on, but if you pay attention is should be OK as well because.... in the case of cameras with no built-in shutter, you change the lenses with a sensor exposed anyway (no matter if the camera is on or off) and I never heard of issues, as long you pay attention at what you are doing.

And here is a shocker... is absolutely nothing wrong with changing the cards in your camera while the camera is ON.
Your camera is like a computer, you can plug and unplug a memory card into a computer without shutting it down no? Same with the camera!
The only thing you have to pay attention is NOT to remove it while the camera is writing to card. That's it!

Any DON'Ts in these situations are nothing but scare stories...

Sooo... Can we agree to disagree, or do we have to mud wrestle about who's right?

[mrNewt]

Sooo... Can we agree to disagree, or do we have to mud wrestle about who's right?

No need to mud wrestle since I know I am right.
However... each person can choose either approach based on their own personal believes and (especially) fears. Fears that most of the times are badly founded.

Anyway, I am not here to argue with anyone, I am just clearing things up for the OP.
Now is up to him to believe what he wants.