alacant

Hi. Yes. Screw the threaded end of the adapter into your t2 ring and attach the bayonet to your camera. Now introduce the other end of the adapter into the ds focuser and tighten the thumb screws whilst keeping the camera pushed up against the focuser tube to keep it as square as possible. Actually, once you've screwed it into your t-ring, it will become obvious what to do. Here's hoping:)

Hi. It replaces the field flattener but with far less optical path and in so doing guarantees focus. Only you can decide. Many of us can't cope with coma. Others struggle to see it. If you're lucky, you may fall into the latter category!

Hi If it will reach focus, try with your field flattener. It may go some way to correct the coma. Or go glassless with -can't tell if your second shot already has- one of these. HTH

Hi. AFAICT, the two coma correctors to which you link are the same. Product description is perhaps not astroshop.eu's strong point. SW do however market a 1x coma corrector. It's called Aplanatic and is a copy of the GPU coma corrector but without possibility of adjustment. The latter is by far the superior of the two at any focal ratio, as is reflected (sorry) in the price. But it's heavy and maybe best avoided for PDS focusers. HTH

Hi Hands on with a SW 250p down to a 130pds with everything in between tells me that binning our t7m (120mini clone) and zwo120mm mini oag gets us a decent calibration and guide star every time. Found out the hard way before I knew about binning;) Sorry, can't speak for the 120 colour but as @wimvb suggests, try it. My money is on a binning success. Cheers and look forward to decent stars every time.

It happens to us all. Me, worse! You use the hole in the card simply to look at the position of the centre screw on the secondary holder to judge whether it is centered, make any adjustments (in your case L to R) and then remove it for the rest of the procedure. I think you'll have it near perfect. They're great portable telescopes. A guy regularly travels here with his as carry on luggage. He fitted a 2" focuser to be able to use a coma corrector. The wide colour free field of view beats any refractor. Cheers and good luck.

Ah, ok. It's probably almost there then. Post a shot through each. That will help diagnose. That and a frame of a star field -anywhere in Cygnus is fine- would help nail it. Cheers

Hi The secondary mirror is intercepting only part of the light from the primary. The most likely cause is that the secondary mirror is rotated, tilted or too far away from the primary or not centred. Or said in any combination. Or something else. E.g. I can see the spider fixing screws at 10 and 11 o'clock, but nothing dianetrically opposite. But best not to guess. You'll need a cap with a centred hole and Cheshire sight tube equipped with cross hairs. They are described in this procedure. That should get you close. If not, post again with views through each of the tools. Before you start, be sure to read the collimation myths. HTH

Hi But the OP will then need another adapter:( Perhaps best to keep it simple and go the direct route with the m48... Cheers

Hi The standard adapters are 9mm, 10mm or 11mm depending upon the make of the camera. You don't say which camera, but all will adjust backfocus of a dslr to around 55mm. e.g. this one (assume Canon as you state 44mm) Cheers and HTH

Hi +1. No need to fumble around alone aimlessly in the dark! You also have the opportunity to see others operate their equipment first hand, something which no amount of research and reading will get you. My advice would be to make your choices after you've seen the gear first hand. Cheers

So, fw + camera = 26.5mm The 54mm click lock is 30mm optical length giving 56.5mm. The Baader cc needs 57.5mm. Sorry, Calculation only. My only hands on was which the GSO cc with has 75mm back focus. Cheers

A DSLR requires 45mm. You have 6. I thought you were using an así 1600. Are you now using a DSLR? The clik lock will not work with a DSLR. Cheers.

Focus is at the same point with or without. You have only about 6mm of back focus: room for the camera, filter wheel and click lock before the cc. But try without first. The thumb screws are probably as good as you'll get.

Hi How about this? But with close on a kilo of stuff that far from the tube on a budget focuser, well... Just my €0,02. Cheers

Hi and thanks for the quote. To be fair, the stretch is exaggerated. It's designed by the Siril engineers magicians to prove just how bad you are at astrophotography. In reality, run it against the photometric colour db and you're looking at something taken on a moonless night. Still magic though! Cheers

OMG. We got a hot thread...

Hi Did you try it? You may be pleasantly surprised. Backfocus: mpcc Baader, 57.5mm. MPCC ES, 55mm. Cheers

Ok now?!

MPCC: explore scientific multi purpose curvature corrector. MPCC: Baader multi purpose coma corrector. AFAICT, the op wanted to know the difference. Cheers

Yes. More so as you move away from centre frame. Best to stick to what the manufacturer states. Cheers

Hi Multi Purpose Curvature Corrector. A 1.0x field flattener designed for refractors. HTH

Hi everyone This month's imaging with a 99% moon challenge. I set EKOS' scheduler for both clusters around 23:30 and waited for the first frame to arrive. Big diagonal gradient and peak dangerously over to the wrong side. Adjusted to 3 minutes and set it going again, but never expecting anything useful. Came back in the morning to find that lime and strawberry syrup had been poured over ever frame. Here's the before and after. With that mess, never expected to get anywhere near. Isn't modern software amazing! Thanks for looking. Canon eos700d @ ISO800 on ES nt150s. Processed using Siril and DarkTable under Ubuntu 18.04. --- --- --- --- --- --- --- --- ---

Hi Over the same period of time, an 8" f7 telescope collects the same amount of light as an 8" f10. The f7 has the advantage that the oag will see more of the sky and so it's more likely to be able to find a suitable guide star. A 2" f4 guide telescope collects far less light compared to either of the 8" telescopes but it sees far more of the sky; it has far more stars from which to choose. Cheers

¡CAUTION! I wouldn't recommend it. The focus position is 35mm further out from normal focus making it very wobbly. Even with a solid 2.5" hexafoc, it was difficult to hold a dslr correctly and balance is made much more difficult as the turning moment at that distance from the tube is excessive. Not workable for us at least, but of course YMMV. It's available here.