continuous shooting, shutter release and mirror lockup

[troypiggo]

How do you guys actually do your long exposures? I have a 30D and the RS-80N3 shutter release. The other night I thought I'd try 1/2 hour of 30sec exposures while having dinner, and try to stack them using Deep Sky Stacker for star trails.

I set the camera to continuous shooting, when doing long exposures I always use mirror lockup, I set the exposure time to 30secs, pressed the shutter release once to get the mirror up, then again to start shooting and slid the hold button over to continue shooting.

I only ended up with the one shot. Did I have too many wines beforehand and forget something or thought I did something but didn't?

Or maybe I shouldn't have enabled MLU? Does that stuff the continuous shooting?

Do you use the same shutter release method? Or do you have/use the timer one where you can set longer exposures? Or do you have some other way of controlling times and shots?

[Adrena1in]

I'm guessing it's mirror lock up, because with that you need to press the shutter twice, but I'm not sure. I did something similar last night, setting the camera going taking 30s exposures, and shot about 200 images, and it worked a treat. (I love this set-up-and-go-away form of Astrophotography! )

[troypiggo]

Ok, thx. Will do some testing... sober this time.

[Nighthound]

Yep, if you use mirror lock you'll need to trip it twice and that means no automated exposures. I have the digital Canon remote. The advantage is setting the exposure time and not having to time it with a watch or keep an eye on the digital counter on the top of the camera. I'd really like a remote control type model for totally hands off triggering but can't justify the added cost.

I bring along a collapsable three step mini ladder that has a bar at the top to hold on to. I place it at the camera end of the rig and loop the release/remote switch and cable around it so that when I trip the exposure I can't tug on the camera and introduce vibration. Just have to remember to unwrap the release before slewing the mount/scope to another target and also watch that as the scope is tracking the remote cable doesn't become tight. I've had the cable get tight before and for a second couldn't figure out why my stars suddenly got really long. (operator error)

[Adrena1in]

Originally Posted by Nighthound

I have the digital Canon remote. The advantage is setting the exposure time...

You can set the exposure time to ANYthing with that, can you Steve? The next time I set mine running for a long time I'll probably hook it up to the computer, which allows me to set the exposure time and the amount of time between exposures, as well as how many shots to take. It'll also store the images on the PC, so I can review them as it goes and see when the dew starts to ruin the pics!

[Nighthound]

With the right cable you can automate with the laptop using programs like Images Plus and others. When auto guiding I have to keep a close eye on things which means I'm never just letting the exposures go for long periods of time so this method doesn't appeal to me. I'm a hands on type person and not one to set up the gear to image and go watch television. Half of the fun for me is the actual procedure and the other half is being under the stars. Television has very little of interest to me anymore. It's been trumped by the universe and night/day photography.

I'm not sure how you overcome the mirror lock issue when trying to automate exposures. It's going to require two trigger movements to get the exposure started. Maybe there's something out there that can do this, don't know.

[troypiggo]

Thanks for your input, guys. So if you're not using MLU, do you find the mirror slap has negligible effect on the shots so is not a problem? Guess so.

@Steve - so your remote is the TC-80N3?

I think there are other 3rd party timer remote cables out there. Might research them more.

[Nighthound]

Originally Posted by troypiggo

Thanks for your input, guys. So if you're not using MLU, do you find the mirror slap has negligible effect on the shots so is not a problem? Guess so.

@Steve - so your remote is the TC-80N3?

I think there are other 3rd party timer remote cables out there. Might research them more.

Yep, that's the one I have. My approach is, everything that has potential to have a negative impact on the exposure should be identified and then eliminated or minimized as much as possible. The same goes for mount performance, it's a process of elimination to get to a level of peak performance.

[troypiggo]

I'm reading reviews of the Aputure timer remote. Seems to be pretty good, and much, much cheaper than the Canon one. Might be sitting under the Christmas tree for me

[Nighthound]

Cool. I'm surprised how identical it looks to the Canon model. Good luck with Santa.

[hollis_f]

Originally Posted by troypiggo

Thanks for your input, guys. So if you're not using MLU, do you find the mirror slap has negligible effect on the shots so is not a problem?

If you've got your camera on a decent support then mirror slap shouldn't be a problem at the sort of exposure times we're talking about. If you're shooting 30s exposures and mirror slap causes vibrations for 0.5s then 98% of the light you're gathering isn't going to me affected.

[troypiggo]

Aah, of course. Hadn't thought about it like that, Frank. Thanks for putting it in perspective.