Canon R5 and external intervalometer issue

[spurscar]

So I've used external intervalometers for years with my T series and 70D bodies but having an issue with the R5.  The external intervalometer works the same as previous ones but just with a different end.  I can set up a run fine, like 4 second shots with a 5 second interval and the external intervalometer seems happy with everything and goes about it's program when I click Start.

The problem is the first exposure opens the shutter but after the 4 seconds isn't ending the exposure and closing the shutter.  The intervalometer goes along it's program unaware the camera never ended that first shot.

Best I'm finding on forums and such in searches is that MAYBE I have a bad (brand new) intervalometer.  Suppose that could be it but wanted to ask if anyone else has run into this behavior before.  TIA!

[Tronhard]

Is there a particular reason you did not use the built-in Interval Timer feature of the R5, as shown on P244 of the manual?

[spurscar]

I should have included that in my original post.  I know the R5 has a (bad) built in intervalometer.  Pretty embarrassing that the camera can shoot 12 or 20 fps but needs 3-4 seconds between interval shots or it gets confused.  A 3-4 second gap is pretty bad for star trails and shouldn't be necessary so that's why I bought an external one that says it is compatible with the R5 specifically.

[jrhoffman75]

Your camera is set to Bulb?

[spurscar]

Yeah and all NR and nanny stuff set to Off as well.  One Shot AF and Single, no burst shooting.

[jrhoffman75]

And manual focus?

[spurscar]

Yes, prefocus to infinity in AF then switch to MF.

[jrhoffman75]

That’s exactly how I do it with my 1D X III (except 12 secs vs 4) and 1 sec between. May be a problem with intervalometer. 

[spurscar]

I guess so.  Mainly was wondering if anyone specifically had used any of these third party external intervalometers with a Canon R5 successfully before I bought a replacement.

This is the one I bought btw: https://www.amazon.com/gp/product/B06XBXWL97/

[jrhoffman75]

See this image

this timer has a unique timing. If you want a four second exposure and a 1 second gap you set the interval at 5 seconds. See if that resolves your issue.