michaelmorris

Thanks for the tip.

Okay. I balanced the mount and tried again. Unfortunately it made virtually no difference to the egg-shaped stars (all all with a same direction to their axis) and PHD2 still reported DEC backlash of around 30 secs. Tried 'north only' and 'south only' Dec guiding and south only appeared to make a big improvement in the DEC guiding graph. However, cloud rolled in before I could tell definitively whether this translated in to nice round stars or not. Anyway, it is some progress. This leaves me with a number of definite actions. 1 - Check the polar alignment - can anyone suggest the simplest alternative to Sharpcap's polar alignment routine to use as a check? 2 - Check for possible differential flexure 3 - Eventually have to try to carry out the DEC backlash adjustment

155 mm tall, 200mm Diameter. Unthread hole through centre with long 250 mm bolt 4 x threaded holes on top to accept the adaptor plate 4 x threaded holes on bottom to attach to 1" thick levelling plate

Nice one Niall The cover is lovely. You're drawing skills really are coming on well this term aren't they!

I use UFOcapture software (great software, rubbish name) which uses 'predictive motion detection' to only record suspected meteors. http://sonotaco.com/e_index.html Basically, the software stores the last x number of frames in a memory buffer and runs a motion detection algorithm on it. If it detects motion that fits the relevant criteria, then it saves the sequence. There is a much less expensive piece of software called HandyAvi that does something similar, but doesn't allow for the analysis of the meteor's path and velocity that can be done with UFO capture. http://www.azcendant.com/

Hi Tim I used Sharpcap's polar alignment tool. After doing this alignment, a 9 mm e.p.in the 9.25" was holding a star in the centre of a reticle for a good 5 minutes then very slowly drifting off to the west. Thinking about it, I've realised that the balance is out in Declination axis by quite a lot. Could that be the problem?

After months of delays I thought I was finally ready to start CCD imaging with my Atik 460 camera and my EQ8 mount. Alas, it was not to be. I'm now getting all my star trailling. PHD2's guide assistant suggests the problem is that it calculates that the mount requires a whopping 31 seconds of backlash compensation on Dec. I've tried running the compensation in North or south only, but this doesn't seem to help. Ideas please?

I've finally grabbed a few minutes to do a basic sort on the videos I captured of this year's Perseids on my main meteor camera (Watec 902H2 Ultimate fitted with 2.1mm f1.0 Computar lens). I recorded nearly 70 Perseids. Here are three of them.

The ideas of fitting pneumatic tyres to the Dob sound like a good, low hassle option. If you then invest in a good laser collimator you could sort out any resulting collimation issues in the field.

Nice

Drill one hole sideways through each bar, about 10cm from the top.. Get two short metal L brackets and connect one to each upright securing each with a single bolt and locking nut so that one flat side of each bracket runs parallel to the back of the seat and the brackets a flush with the front of each upright. Cut a piece of wood to make a back rest. If necessary, glue in small packing pieces of wood to ensure the backrest sits tight against the uprights. Secure the back of the wooden backrest to the brackets with wood screws. Simples.

A point source flash of light could be a number of things such as a tumbling satellite or a head on meteor. How long did the 'flash' last for?

I certainly couldn't find one. My mate Chris made this 15 cm one for me. It's made out of a solid block of aluminium!

With a external width of only 4' 9" and a roof height of only 4' 1", it would certainly be a bit of a squeeze! My guess is you'll need something much bigger if you intend to in the observatory yourself. I would have thought that 6' x 6' (internal area) would usually be deemed the minimum size for an observatory you can visually observe from. Your best bet is to set up your whole kit and mark on the floor the minimum internal size you're going to need to be able to use the scope with comfort. (I used garden canes). Don't forget to include space for shelves, storage and (if desired) a computer. I would also factor in the possibility of upgrading your scope set up at a later date. I hope this helps.

Three months ago I remounted the EQ8 in the observatory after my friend Chris made me a pier extension to raise the mount 15 cm. Unfortunately, a combination of cloudy nights, holidays, it not getting dark until early in the morning, and my lovely wife being ill has meant that it took until tonight to get the EQ8 re-polar aligned. SharpCap's polar alignment tool makes this pretty easy. I used my Lodestar x2 mounted on a 60 mm finder/guider. I'll aim to try to see if I can get this even closer with full drift alignment on another night, but my guess that'll be close enough for now.