I’m having trouble focusing when using my Canon EOS 1000D DSLR camera on my Meade LX90. Any advice?
The Meade LX90 is a Schmidt-Cassegrain telescope (SCT) mounted on a twin tine fork mount.
This type of instrument has a visual back with a threaded mounting and a push-fit adaptor for attaching the star diagonal.
For photographic use, the push-fit adaptor and star diagonal should be removed and a Meade Instruments 07352 No. 62 SLR Camera T-Adaptor screwed onto the visual back in its place.
To mount the Canon 1000D onto the adaptor, a standard Canon to ‘T’ mount adaptor will be required.
Focus is best achieved by taking a series of 10-second exposures of a bright star and adjusting the focus position between shots until the smallest star image is produced.
A Bahtinov mask, available from most astronomy retailers, will make this task even simpler.
Viewing the captured images directly on a laptop computer screen, using the EOS Utility software supplied with your camera, will make the task easy and comfortable.
Email your astronomy queries to Steve at scopedoctor@skyatnightmagazine.com and they could get answered in a future issue of BBC Sky at Night Magazine.
