Canon mirror lock up and vibrations

[perfrej]

Hello!

The season has definately come to and end here with barely one hour of proper darkness.

Night before last I set up the FLT98 for a quick star-grab to check out how it actually is optically. Last time all my stars were slightly oval, but just the bright ones. Tracking? Never been an issue for me.

So I aimed at Mizar and shot at short exposure time. Oval stars!

Changed to the Meade DSI. Round stars... (I can not get focus properly with that camera, even though I use a bahtinov, but that's another issue)

So, it must be mirror vibrations in my Canon 1000D.

Canon doesn't support mirror lock-up when using the internal DIGIC processor for timing of bulb exposures. The latter a feature that apparently all software packages make use of.

How the heck do I solve this? Any ideas from my fellow astromaniacs?

All the best and greetings from the light summer nights of the North,

Per

[Carbon Brush]

I cheat and use an external timer into the remote button for exposures >30sec.

I remember reading somewhere that the USB command structure for shutter is <shutter - time>. As there are no separate <shutter open> <shutter close> commands, you can't get long exposures timed from USB commands. That is why I went for the external timer on a wire.

But if someone knows more I'm listening.

David.

[Psychobilly]

There is a work around using the Self timer in combination with with a serial shutter cable or remote timer.. unfortunately EOS Utils doesnt allow you to use the Self Timer in combo with long exposures...

You need to enabel mirror lockup onthe camera add the self timer duration to the exposure one or you will get shorter exposures...

Bascially the signal form the remote will open the mirror and start the self timer and the shutter will open when the self timer finishes and then remain open until the remote tells it to close..

[perfrej]

Case solved!

I just built a remote shoot thingy with serial port control. It took one 2.5mm plug, a 2.2k resistor, an SFH615A optocoupler and a 1N4148 diode, all mounted directly in the DB9 connector. I just happened to have all the stuff in my drawers

It works great with Nebulosity2.

As soon as the skies clear up and I have the energy to stay up until 1 a.m. when it gets reasonably dark, I will try to shoot a frame or two with mirror lock up.

/per

[perfrej]

So, even though it doesn't really get dark this time of year, I managed to squeeze out a few exposures of M101 last night. It is six exposures of 10 minutes each at ISO 400 with the EOS 1000D on the FLT98. Flattener set to WO recommended of 76.8 mm.

I apologize for the state of the image. No flats, no darks, no bias frames, just the six lights. Processing the background of a not completely dark sky is a total mess.

Anyway - round stars! Yipeeee!

/per

(Full res JPG Here)

[cervesca]

Wouldnt apologise for that pic looks excellent! I noticed thers no mirror lockup on the new models, use the cap as a shutter?

[perfrej]

That would call for a long night of attention

[Psychobilly]

Wouldnt apologise for that pic looks excellent! I noticed thers no mirror lockup on the new models, use the cap as a shutter?

Any models in Particular.. with the Canons It's often buried in the custom functions menu.. the later (DIGIC IV) camera also allow true Mirror lockup over USB...