Intervalometer time is gap time, should be shot to shot time

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Set Interval time to 15s
2. Set exposure time to 8s
3. Start intervalometer

What is the expected output?

  Expected 1 shot every 15s

What do you see instead?

  Got 1 shot every 23s (8s exposure + 15s gap)

This is not ideal, as when shooting in varying light (eg dusk), as the exposure 
is adjusted, the timelapse speed also changes.

The intervalometer setting "time" should be the exact duration from the start 
of shot n to the start of shot n+1.  This allows the exposure to be varied 
without changing the timelapse speed.

What version of the product are you using?
20111111-1

Please provide any additional information below.
If this is rejected, I suggest the documentation is updated to clarify that the 
time is the gap time, not the shot to shot time.

Original issue reported on code.google.com by datagro...@gmail.com on 11 Dec 2011 at 12:36

[GoogleCodeExporter]

It seems to me that it works the way my Canon timer remote works i.e. the 
interval time is the time between shots, not the overall time. Each function is 
done independently. The interval timer begins counting after the shutter is 
depressed, so it's completely independent of exposure time. I could take a 5min 
exposure with 15 sec between the exposures. 
http://learn.usa.canon.com/app/pdfs/quickguides/CDLC_TC-80N3_QuickGuide.pdf

This is how I thought all remote timers worked.

Original comment by colinban...@gmail.com on 11 Dec 2011 at 6:50

[GoogleCodeExporter]

This is a bug, indeed.

Original comment by eduardo....@gmail.com on 11 Dec 2011 at 8:52

• Changed state: Accepted

[GoogleCodeExporter]

A clarification of comment #1 regarding the TC-80N3.  I have the TC-80N3 
timer/remote controller.

If I set Interval=15s and shutter speed (on the camera) to 8s (or 1s, 2s, 4s), 
I get 1 exposure every 15 seconds.  I can change the camera shutter speed 
without affecting the timelapse interval, until my shutter speed reaches 
(slightly less than) 15s, when frames begin to be dropped.  That is because the 
TC-80N3 is just pressing the shutter button every 15s.

The TC-80N3 also has a "Long Exposure Mode" that the 400plus firmware currently 
does not imitate. You can set the camera in bulb-mode, and let the TC-80N3 
provide a long exposure (in 1-second steps, up to 99h:59m:59s).  In this mode, 
the two settings are additive, so the time between exposures is "Bulb Timer" + 
"Interval".  But this is a combination of 2 modes, rather than the behaviour of 
the "Interval Timer Mode" in isolation.

More sophisticated intervalometers (like "The Little Bramper") allow the bulb 
time to be adjusted in tiny steps (from 1/10s in 1ms steps), without affecting 
the timelapse interval.  This allows smooth adjustment of exposure during 
sunrise/sunset, without the flickering that 1/3 stop adjustments cause.  A 
great feature, but beyond the scope of this issue.

Original comment by datagro...@gmail.com on 11 Dec 2011 at 9:51

[GoogleCodeExporter]

I also think that the intervalometer should just "press the shutter button" at 
constant intervals, and exposure time should not affect the cadence of shots; 
what it currently does is just add a fixed pause between shots, thus the 
problem described. And this does not affect only long exposures, remember the 
intervalometer can also be used to trigger the EAEB script (which could also do 
long exposures, by the way). Manually adjusting the intervalometer to take into 
account the exposure time may be impossible in some situations (think Av mode 
and low light, for example).

Magic Lantern can do automatic bulb ramping (exposure is adjusted as light 
changes), but that is currently off-limits for 400plus; however, fixed bulb 
ramping, like what "The Little Bramper" does, looks very doable. Please, fill a 
separate feature request if you are interested.

Original comment by eduardo....@gmail.com on 11 Dec 2011 at 10:26

[GoogleCodeExporter]

This issue was closed by revision r1127.

Original comment by eduardo....@gmail.com on 13 Mar 2012 at 10:35

• Changed state: Fixed