Tomatobro

What part of the sky was the scope looking at when attempting the calibration?

Yes that is the camera I use.

I bet it's that USB C connector on the camera. I fold back the ribbon cable and put a tie wrap round the camera body to take the strain off the usb connector.

2 hours cool down for the optics minimum.

You just cannot go wrong with the Star Adventurer as a basis to start Astro imaging. Having owned one for a while its easy to see why millions have been sold worldwide.

I have built three and the lesson I have learnt is that the lens is everything if you want good results i.e. capture more than just the very brightest. Much will depend on your DIY and computing skills so give it a go as you can always upgrade later on as you gain experience

I don't have a cat but my neighbours cat Thomas will pay me a visit in the observatory and checks that I am doing everything correctly before going off on his night patrol. Telling him to be quiet has no effect.

I have a similar clamp. It can be slid further up towards the sensor end leaving the vents open.

Opps its pi X d not r.......my mistake

Have a look at https://optcorp.com/blogs/astronomy/how-to-set-the-correct-back-focus

No. Thanks for the heads up. I will go find the magazine and read up. Ordered the dome drive and powered shutter kits from Flo this morning

The easy way to check RA tracking is to set the mount up in a room or garage. Put a laser pointer in the mount (improvise with tape etc to hold it in position). Turn on the mount and laser and measure the distance from the centre of the mount to where the laser dot is on the wall. set the mount up and start sidereal tracking. Some maths is now required. Say the distance to the wall is 3000 mm. 3000 x 3.142 = 9426 mm 9462 / 24 = 393 mm Mark the wall and let the mount run for exactly 1 hour. If the dot has moved 393 mm (or pretty near) then the RA tracking is good.

Switch mode power supplies are low cost, small and efficient but not very good at dealing with transients whereas Linear are expensive, large and relatively inefficient but are very good at coping with transients. Either will work but the power supply of choice would be the Linear. Adjustable voltage outputs allow compensation for the volt drop caused by cabling and load variations, again not essential but good to have if you can have it with the power supply.

Re the finder scope if you can then invest in a 90 degree finder that will solve the problem of the awkward viewing position. Use a distant tree or roof Ariel during daylight to align the finder scope to the main scope. Only use the barlow and high power eyepieces when you become familiar with using the scope

Re the Batinov mask, the guy I purchased the fine focuser collar from also 3D printed a focus mask for me. I found that it worked but need a bright star to work well. I purchased a Williams Optics one from Flo and its a lot better. Not cheap though.

Having recently purchased a new Pulsar dome (assembly delayed) I am starting to think about dome rotation hardware. I have permission from the Finance Director to purchase a Pulsar dome rotator kit but having read a few reports on problems with them I am unsure which way to go. Would be glad to hear from members who have one and have comments good or bad. Perhaps there is a tendency for satisfied users to keep quiet?

Any reports on the Sharpcap forum?

The only advice I can give is that I have machined up several adapters to marry the Samyang 135 to various cameras an filter wheel combos I make the initial back focus distance about 4mm longer than the specifications suggest and mount the camera and lens in a Alt Az mount and point it on a distant tree (about 750 metres away) and see if I can bring the branches into focus. I then disassemble, machine off 1.5mm and retest. As I get near to focus at the infinity mark I machine off another mm and again retest. Repeat the procedure till focus is obtained.I find that in general the back focus distance is about 1 to 1.5 mm shorter than the initial calculations suggest. At this I can focus at infinity and have a little bit of adjustment headroom. This might help with the spacer question

A 81 year old astro club member asked if I could make him a setup using some vintage Minolta SLR lenses. Pictures attached for interest.

Yes. The standard SW one works ok for polar alignment it just takes a bit longer to achieve. The WO unit just shaves a few minutes off the setup time.

Samyang 135mm f2 with a Horizon2 OSC camera. Pulse guided with PHD2. Sharpcap 3.2. Navigation via plate solving. Polar align using Sharpcap To fast find use an angle finder to set the counterweight bar horizontal than transfer the angle finder to the lens clamp. Look up the altitude (not RA) of the object in Stellarium and adjust the angle of the lens to match. Turn on Tracking. Swing the lens to roughly where the object is and plate solve. Adjust the Dec (and only the Dec) till correct. Then adjust the RA and plate solve. keep plate solving and adjusting RA till object is centred. Tip. If using batteries to power the mount remove one battery before storing the mount. Its very easy to turn the rotary switch on when packing away. removing one battery means mount cannot be turned on by accident.

When tightened down it locks the saddle boss to the worm. When loose it allows the saddle boss to rotate. In practice the act of tightening will cause the saddle boss to deflect so the object in view will move. When loose you can grad the scope and position it manually, when tight position by using the black knob. In the dark I have been known to loosen the centre holding screw and not the larger clutch ring.

I find the high entrance angle ones are most likely to occur just after midnight and the longer trails just before dawn. Reviewing the images does occasionally produce a "what the...." response!

sometimes meteors come towards the camera head on. I caught one the same night.

Meteors from the other night