R5 intervalometer exposure issues

[Paul Gath]

Thanks drsnoopy. That seems to be the consensus of opinion.

 

[Nimonus]

I know one more victim trapped by the Canon interval timer when I read the title.

So many cases. Canon, can you listen to the users, change the interval timer to anything else that easier to understand and use?

 

[Andy01]

I was out photographing the northern lights last night. Manual exposure. F4, iso3200, 13seconds. Everything was exposed perfectly. I then turned on the intervalometer to record a sequence of images for a timelapse, same exposure settings, but the images were all 3 or 4 stops underexposed.

Reviewing the images on the camera showed exactly the same settings from the metadata of the images, but they were underexposed.

I've done a very small experiment in the daylight this morning and everything seems to be.

Any ideas?

I think you have a different issue to the common shutter speed vs interval timing issue.

There are many threads in this forum, M forum and DSLR forums about this because it catches many people (me included).

AFAIK the mirrorless work exactly the same way as the DSLRs - the interval HAS to be a couple/few seconds longer than the shutter speed. This includes the 5D iv.

For a 13 second shutter speed the interval would need to be at least 15 seconds, 34 second interval for a 30 second shutter speed etc.

However, the usual symptom of making this mistake is simply skipped shots. Ask for 10 shots at 10 second shutter speed with interval set to 2 seconds and you will probably get 2, maybe 3 shots because the camera is trying to take a shot every 2 seconds but it is busy with an exposure for 10 seconds so it simply skips a few until it is ready.

I have never had it underexpose shots to achieve the required interval & selected number of shots. Maybe this is a new thing on the R5 ? Otherwise I have no idea what this under-exposure issue is as I have never seen it before.

 

[EmotionBlur]

<edit> I just tried myself, never activated it before, and jeez did Canon make a mess with that option... I could not make it work :/

After reading this I had to try it on my R3. Haven't done that before either.

Piece of cake, though. Worked immediately. Took five pictures three seconds apart.

I set the intervalometer to 2 sec and 10 shots, M mode, exposure 8 sec. It did two shots exposed 8 sec and then it stopped... Tried the same with 4sec exposure, it did 4 shots.
A strange cake, dare I say. Like first it computes the total time for the shooting (2 sec interval x 10 shots = 20 sec) and then it does all the shots it can at 8 sec + 1 sec pause from each other in that time window.

You read correctly, 1 sec, not 2. I set the interval to 5 sec and it didn't change one bit, still 1 sec. That's probably because the exposure time is longer than the interval time so it shortens to the minimum.

It's a total nonsensical mess. Nevertheless, the exposure was correct.
--

Luc

Let me try and post 2 raw images, one taken with and one without the intervalometer to demonstrate the problem. Might be a challenge from my current location, but I'll try.

A couple of JPG exports. Consecutive images. Same settings. Very different exposures. I hope the exif data remains intact after the uploads.

Exif is exactly the same, I see no "auto" anywhere. Adding nonsense to nonsense.

Did you check that the timing was in fact 13sec exposure + 2 sec interval + 13sec exposure + ...?

--
Luc

 

[apersson850]

IMHO it's not a great implementation because it means that if you need to change your shutter speed between subsequent timelapse sequences, you also have to change the interval in the timelapse settings.

In my opinion it's the only sensible. And for all "normal" exposure times it doesn't matter, since they are significantly shorter than even one second, which is the shortest interval you can set.

It's also the simplest, since you don't need to do any math. If you want 15 second intervals, just set that. The only thing you then need to think about is that the exposure should be shorter. And if you do miss that, it will simply skip that interval and pick the next.
I don't know if there's any difference in handling when using an internal timer in the camera. I've not had a camera with that since the EOS 10. My 1DX models I've used with the TC-80N3, which simply pushes the button at a certain interval. It has no clue if the camera is ready or not by then. With an internal timer, you do have the option to either skip exposures or just make them as soon as possible.

Example: As it's now, if you set 10 second interval and shoot with one second exposure, you get 10 second interval.
If you change to 15 second exposure, you get 20 second interval, since every second one is void.
A possible implementation would be that you get 10 second intervals as long as the exposure is shorter, but start getting 15 second intervals if the exposure is 15 seconds, and so on.

 

[EmotionBlur]

IMHO it's not a great implementation because it means that if you need to change your shutter speed between subsequent timelapse sequences, you also have to change the interval in the timelapse settings.

In my opinion it's the only sensible. And for all "normal" exposure times it doesn't matter, since they are significantly shorter than even one second, which is the shortest interval you can set.

It's also the simplest, since you don't need to do any math. If you want 15 second intervals, just set that. The only thing you then need to think about is that the exposure should be shorter. And if you do miss that, it will simply skip that interval and pick the next.

I just tested it yesterday and Canon couldn't have messed it up more (see my comment above). My conclusions:

1) The interval starts when the shutter opens. If the exposure time is longer than the interval, the gap between shots becomes about 1 sec.
2) The number of shots you set is NOT the number of shots you'll get. It's just a multiplier for the interval time, to get the total time of shooting. So if you set 10 shots and 1 sec interval timer, the whole session will last 10 sec, no matter the exposure time; i.e. 10 sec exposure time will result in 1 shot, 5 sec in 2 shots etc. This does not make any sense by any stretch of imagination, and makes things pointlessly more complicated with no pros whatsoever. If I set 10 shots, I want 10 shots.

--
Luc

 

[apersson850]

So many cases. Canon, can you listen to the users, change the interval timer to anything else that easier to understand and use?

It can't really be easier than that the interval is the time between shots. As it is now.

That you can't keep on exposing longer than the interval - well, that's at least less difficult to fathom than that your interval starts changing each time you select a different exposure time.

 

[apersson850]

I set the intervalometer to 2 sec and 10 shots, M mode, exposure 8 sec. It did two shots exposed 8 sec and then it stopped... Tried the same with 4sec exposure, it did 4 shots.
A strange cake, dare I say. Like first it computes the total time for the shooting (2 sec interval x 10 shots = 20 sec) and then it does all the shots it can at 8 sec + 1 sec pause from each other in that time window.

You read correctly, 1 sec, not 2. I set the interval to 5 sec and it didn't change one bit, still 1 sec. That's probably because the exposure time is longer than the interval time so it shortens to the minimum.

It's a total nonsensical mess. Nevertheless, the exposure was correct.

No nonsense there, except for setting an exposure time longer than the interval, of course.

 

[EmotionBlur]

I set the intervalometer to 2 sec and 10 shots, M mode, exposure 8 sec. It did two shots exposed 8 sec and then it stopped... Tried the same with 4sec exposure, it did 4 shots.
A strange cake, dare I say. Like first it computes the total time for the shooting (2 sec interval x 10 shots = 20 sec) and then it does all the shots it can at 8 sec + 1 sec pause from each other in that time window.

You read correctly, 1 sec, not 2. I set the interval to 5 sec and it didn't change one bit, still 1 sec. That's probably because the exposure time is longer than the interval time so it shortens to the minimum.

It's a total nonsensical mess. Nevertheless, the exposure was correct.

No nonsense there, except for setting an exposure time longer than the interval, of course.

Setting 10 shots and getting only one makes sense to you?

 

[apersson850]

EmotionBlur, post: 66523657, member: 717079"]You read correctly, 1 sec, not 2. I set the interval to 5 sec and it didn't change one bit, still 1 sec. That's probably because the exposure time is longer than the interval time so it shortens to the minimum.

[/QUOTE]
If that's what happened it makes perfect sense. You made a stupid setting - the camera did the best it could out of it.

 

[apersson850]

I set the intervalometer to 2 sec and 10 shots, M mode, exposure 8 sec. It did two shots exposed 8 sec and then it stopped... Tried the same with 4sec exposure, it did 4 shots.
A strange cake, dare I say. Like first it computes the total time for the shooting (2 sec interval x 10 shots = 20 sec) and then it does all the shots it can at 8 sec + 1 sec pause from each other in that time window.

You read correctly, 1 sec, not 2. I set the interval to 5 sec and it didn't change one bit, still 1 sec. That's probably because the exposure time is longer than the interval time so it shortens to the minimum.

It's a total nonsensical mess. Nevertheless, the exposure was correct.

No nonsense there, except for setting an exposure time longer than the interval, of course.

Setting 10 shots and getting only one makes sense to you?

You wrote you got two, or four, depending on which unrealistic exposure you selected to go with it. Makes sense.

What doesn't make sense is of course to tell the camera that you want ten exposures within 20 seconds, and each should last eight seconds.

--
Anders

 

[Paul Gath]

I was out photographing the northern lights last night. Manual exposure. F4, iso3200, 13seconds. Everything was exposed perfectly. I then turned on the intervalometer to record a sequence of images for a timelapse, same exposure settings, but the images were all 3 or 4 stops underexposed.

Reviewing the images on the camera showed exactly the same settings from the metadata of the images, but they were underexposed.

I've done a very small experiment in the daylight this morning and everything seems to be.

Any ideas?

I think you have a different issue to the common shutter speed vs interval timing issue.

There are many threads in this forum, M forum and DSLR forums about this because it catches many people (me included).

AFAIK the mirrorless work exactly the same way as the DSLRs - the interval HAS to be a couple/few seconds longer than the shutter speed. This includes the 5D iv.

For a 13 second shutter speed the interval would need to be at least 15 seconds, 34 second interval for a 30 second shutter speed etc.

However, the usual symptom of making this mistake is simply skipped shots. Ask for 10 shots at 10 second shutter speed with interval set to 2 seconds and you will probably get 2, maybe 3 shots because the camera is trying to take a shot every 2 seconds but it is busy with an exposure for 10 seconds so it simply skips a few until it is ready.

I have never had it underexpose shots to achieve the required interval & selected number of shots. Maybe this is a new thing on the R5 ? Otherwise I have no idea what this under-exposure issue is as I have never seen it before.

Thanks Andy. I agree, which is why I raised it here, although I've also learnt more about the interval. Historically, I've assumed it was the time between the end of the previous shot to the start of the next. Having only ever used it for northern lights, with long exposures and unlimited frames, I have not noticed missing frames.

If the clouds clear before I have to leave, I will try it again with a longer interval and see if the same thing happens with the exposure.

Thanks for all your help everyone.

 

[EmotionBlur]

I set the intervalometer to 2 sec and 10 shots, M mode, exposure 8 sec. It did two shots exposed 8 sec and then it stopped... Tried the same with 4sec exposure, it did 4 shots.
A strange cake, dare I say. Like first it computes the total time for the shooting (2 sec interval x 10 shots = 20 sec) and then it does all the shots it can at 8 sec + 1 sec pause from each other in that time window.

You read correctly, 1 sec, not 2. I set the interval to 5 sec and it didn't change one bit, still 1 sec. That's probably because the exposure time is longer than the interval time so it shortens to the minimum.

It's a total nonsensical mess. Nevertheless, the exposure was correct.

No nonsense there, except for setting an exposure time longer than the interval, of course.

Setting 10 shots and getting only one makes sense to you?

You wrote you got two, or four, depending on which unrealistic exposure you selected to go with it. Makes sense.

Er... nope. Not at all.

What doesn't make sense is of course to tell the camera that you want ten exposures within 20 seconds, and each should last eight seconds.

I didn't tell the camera to do "all in 20 seconds", I told it to take 10 shots. That's what's written in the menu. Dude come on, you're climbing on mirrors now.



We can reverse engineering the camera's logic how much we want, but it's pointless to let it behave as if it had an external timer that "tries" to press the shutter while it perfectly knows that it's already pressed. There's no point in that.

--
Luc

 

[EmotionBlur]

However, the usual symptom of making this mistake is simply skipped shots. Ask for 10 shots at 10 second shutter speed with interval set to 2 seconds and you will probably get 2, maybe 3 shots because the camera is trying to take a shot every 2 seconds but it is busy with an exposure for 10 seconds so it simply skips a few until it is ready.

Well this is not very intuitive is it? If the camera is taking a shot, it should not "try" to take another while exposing, it should not do hidden multiplications like interval time x number of shots to get a total shooting time, and on top of that not even showing that. If I set 10 shots, I want 10 shots. Period. This is not an external timer, the camera knows what's going on.

I have never had it underexpose shots to achieve the required interval & selected number of shots. Maybe this is a new thing on the R5 ? Otherwise I have no idea what this under-exposure issue is as I have never seen it before.

I did not experience such an issue with my test on r6 yesterday, but hey... it took only 2 shots each time I tried

--
Luc

 

[apersson850]

I didn't tell the camera to do "all in 20 seconds", I told it to take 10 shots. That's what's written in the menu. Dude come on, you're climbing on mirrors now.

Try take 10 and multiply by 2. The rest of us will get 20. I hope you get the same.

So yes, you asked for one exposure every other second during 20 seconds. And then you asked for each such exposure to last for 8 seconds.

What the camera could have done was to display a message, like "Are you daft or something?", but it did the best it could from your contradicting orders.

--
Anders

 

[apersson850]

If I set 10 shots, I want 10 shots.

Yes, and if I tell you to go 200 km/h, I don't give you a regular bicycle for the task. Because common sense will tell me that's impossible.

They are doing the only sensible thing, doing the user the favor of expecting them to understand that you can't do ten exposures, each eight seconds long, in 20 seconds.

 

[apersson850]

Well this is not very intuitive is it?

It's extremely intuitive, since it will give exactly the same result, regardless of which exposure time you use. As long as you do realise that you can't do a ten second long thing every two seconds. Which is reasonable to expect from people.

But if you set 10 second intervals, for example, then you get exactly the same result regardless of whether you shoot for 1/8000, 1/125, 1/2 or 4 seconds, to list a few options. Which is the only thing that makes sense.

Besides, it has the additional advantage of behaving exactly the same way as Canon's timing devices have done since the days of the Canon F-1. No need to re-learn some new strategy.

 

[EmotionBlur]

I didn't tell the camera to do "all in 20 seconds", I told it to take 10 shots. That's what's written in the menu. Dude come on, you're climbing on mirrors now.

Try take 10 and multiply by 2. The rest of us will get 20. I hope you get the same.

So yes, you asked for one exposure every other second during 20 seconds. And then you asked for each such exposure to last for 8 seconds.

What the camera could have done was to display a message, like "Are you daft or something?", but it did the best it could from your contradicting orders.

Nope, my "orders" are not contradicting. Again, this is not an external timer, this is the camera itself. The system is confusing; there's no "20 seconds" written anywhere, and there shouldn't be. "No. of shots = 10" it means "10 shots", not "hey do the multiplication, divide by the maximum between the exposure time and interval time, you guess the actual number of shots."

I don't understand what you and other people here find the latter idea more simple, it's simply, objectively, not.

--
Luc

 

[EmotionBlur]

If I set 10 shots, I want 10 shots.

Yes, and if I tell you to go 200 km/h, I don't give you a regular bicycle for the task. Because common sense will tell me that's impossible.

No, that's entirely possible, do 10 shots as I set it.... overlap the interval, it'll be 10 shots 8 seconds long. What exactly is "impossible" with this? Where did I ever set the maximum time?

"No. of shots" means goddamn NUMBER OF SHOTS.

You keep climbing on mirrors...

 

[EmotionBlur]

Well this is not very intuitive is it?

It's extremely intuitive, since it will give exactly the same result, regardless of which exposure time you use. As long as you do realise that you can't do a ten second long thing every two seconds. Which is reasonable to expect from people.

Nope, the number of shots varies depending on exposure time, given a requirement limit (total shooting time) that's not written anywhere and you have to compute in your mind after you tried the first time and wondered what the hell is going on.

Let's say I want to do a video N seconds long. I plan to use a certain framerate, I get the number of shots, I want that same goddamn number of shots from the camera, no matter the exposure time. I don't want to compute stuff by reverse-engineering the hidden logic in the camera. "Extremely intuitive" is the extreme opposite of reality....

But if you set 10 second intervals, for example, then you get exactly the same result regardless of whether you shoot for 1/8000, 1/125, 1/2 or 4 seconds, to list a few options. Which is the only thing that makes sense.

If. Otherwise, I don't.

Besides, it has the additional advantage of behaving exactly the same way as Canon's timing devices have done since the days of the Canon F-1. No need to re-learn some new strategy.

Well I used the external timer with my 5D3, and I was expecting it to not have a clue about how the camera exposure is set, and guess what now. The camera has no clue on how its own exposure time is set, it pointlessly simulates an old system which was intrinsically more complicated. And how about someone who has never done timelapse before...

--
Luc