biases and auto flats with DSLR and shutter release cable in autorun

AntoonH

I have a canon 5DmkIV attached to my asiair plus with a USB cable.

Now, when I create an auto run with

bias at the lowest shutterspeed (1/4000)
darks at 30 sec
lights at 30 sec
auto flats

This all works as expected: The autorun produces all the frames I selected.

However, when I connect a shutter release cable (to achieve > 30sec exposures) and enable the cable in main camera settings, I set an autorun like so:

bias at the lowest shutterspeed (1/4000)
darks at 2 minutes
lights at 2 minutes
auto flats

This sequence just fails to take exposures for flats and biases.
When I split the autorun in 2 parts:

-- shutter cable enabled --

2 minute darks
2 minute lights

-- shutter cable disabled --

biases (at lowest shutterspeed)
auto flats

This works.

My thinking is that enabling the shutter cable disables short exposures, causing both the very short bias frames as well as the auto flats (which look like it does a sequence of exposures at various lengths) to fail.

Am I missing something? Surely this can't be expected behaviour?

nicolas

Hi @"AntoonH"

Where did you see that you need a shutter release cable to achieve > 30sec exposures?

I'm quite sure this is not true because I have used many Canon cameras with an Asiair without a release cable (but not this particular model) and the ZWO documentation clearly states that you only need the shutter release cable for a small number of Nikon models.

AntoonH

Well. When I just connect the 5Dmk IV with USB (and not using the shutter cable), the max shutterspeed I get to set is 30 seconds!

This behavior never struck me as out of the ordinary, because 30 secs is just the max exposure that you can set in the 5D mk iv. For more general nightscapes and long exposure shots, I resorted to using a canon TC-80N3 timer. Similar to my previous 5D mark II.

nicolas

AntoonH
But what exactly happens if you set your 5d mk IV to bulb mode and try a 1 minute exposure?

I've used at least half a dozen Canon cameras with an Asiair and have always been able to get exposures longer than 30 seconds.

AntoonH

I can get darks and lights just alright at any exposure over 1 sec. biases at 1/4000 and auto flats (which goes through a cycle to evaluate the correct flat exposure) don't. To be precise, if I create an auto run sequence with lights, darks, bias, flats... the capturing of images just hangs at the bias stage.

The way I "overcome" it is by doing an autorun with lights and darks, followed by disabling the shutter cable in the menus, then reset the autorun and do a bias/flat run.

nicolas

AntoonH

You didn't answer my question. I understand you have a problem doing bias ant autoflats with the shutter cable but my point is you don't need it. The correct way to use your Canon with the Asiair is without the shutter cable (and with the option turn off in the settings).

If that does not work for you, please explain exactly what is happening.

CKAJCA

From what you described, I have a VERY similar problem with my Nikon D700.