I have got a basic set up for a fellow teacher who wants to get his Yr 11 Physics kids taking pictures. He has several options but I have tried to get the equipment he purchased up and running as it has sat in the same box for nearly two years after it arrived.
Attached are images of the set up ( needs to buy guide rings and skywatcher style dovetail for a side by side set up ), M 20 which is 18 x 2 minute subs with only darks applied, and finally a crop of an area showing the elongated stars. the focusser is standard without 10:1 ratio. I have not tried to collimate as it is brand new so maybe later down the track. Mount is an HEQ5Pro with 15Kg hanging off it.
Instead of a side by side arrangement that will add considerable weight, why not use a finder scope as a guide scope - 15kg has to be pushing the friendship with an EQ5. If you fiddle with the setting in PHD, they work well with even longer focal length instruments - I think it's "minimum move" that you need to reduce??
Hi Mark. that's a pretty good first light - looking promising.
At f4, the collimation needs to be spot on and this doesn't look like it is. Assuming the scope has a coma corrector, star elongation like that can be due to the scope optics being aligned on a different axis to the coma corrector. Suggest a laser collimator (which will also need to be aligned unless it it a top line one) and align the scope collimation through the coma corrector.
The outfit is right at the top of the HEQ5 comfort zone re weight, but it will do the job OK if there is no wind and it is properly balanced (and if you tie down the cable on the guide camera).
Edit: agree with David re lighter guide scope - I use a modified finderscope on my f4 system and it works well.
15kg is too heavy astrophotographically for an HEQ5 - more like 12kg MAXIMUM. The Chinese load limits (17kg for the HEQ5) are both OPTIMISTIC as well as being ALL UP WEIGHT - not photographic.
DEFINITELY need a finderscope guider if using an HEQ5 with this setup. I bought one of the Orion mini's (pretty average finderscope!), took the adapter off and put it on a Takahashi finder (same thread etc). Works delighfully, and is LIGHT.
I assume that the 15kg refers to the 3x5kg counterweights. The scopes etc will probably weigh about 10-12kg?? which is within the mount's specs (eg Bintel quote loading as Total weight: 15kgs (counterweights not included)) . It will work OK if you are careful with balance, but minimising weight in any way you can will be a good idea. Attached image (scaled 0.5) was taken some time ago with a similar scope/mount setup and shows that the HEQ5 mount can do OK with ~11kg load - there were coma and processing problems, but the mount did fairly well. If you were starting from scratch, get an NEQ6, but you have the HEQ5 and it will almost certainly be suitable for the stated task - tidy up collimation a bit and then see if there is much differential flex between the two scopes. If there is too much, get a smaller/lighter guide scope.
