Adam J

Oh its beyond its warranty and there is no dispute with the "second hand" seller as my friend is not in contract with him on the matter, he is just going to suck it up and pay to get it sorted. I was not really expecting Es to be avaliable Steve hence my comment to GarryBlueBoy. Broadly speaking though it is surprising how few people are available to do this kind of work in the UK. It actually makes me want to teach myself the trade as clearly there is a gap in the market and some money to be made once you have sufficient experience to work on telescopes that are not your own with confidence. There is a book called Star testing and adjusting astronomical telescopes on amazon, I may make a purchase. I guess the way forward would be to get an old cheap triplet in good working order and use it as a test subject by deliberately messing it up and then leaning to fix it. Guess that I would have to make some optical test equipment too. Adam

No one seems to know how to get in touch with him or if he is doing private work (ie not for FLO).

When using a heavy camera and with the additional weight of the auto focuser you are forced to place the rings as far forward as possible, the 130PDS already suffers from being nose heavy.

Won't work gets in the way of the tube rings.

ok its just the focus cube that has issues with the 130PDS then, to be honest though none of these work with every scope on the market, you just cant account for all the variations.

The TS Newtonians are good scopes but to be hones F4 Newtonians are fiddly things that I would avoid personally. I would just go with the F5 and stick at that or you end up swapping a focuser issue for colimation troubles.

I would warn you that for any of those models (I used the focuscube) you will need to modify the 130PDS focuser to allow connection as the body of the auto focuser interferes with the spider vane thumb screw. You need to cut down the pin and mount the auto focuser upside down. I got that model in the knowledge that I was going to be moving it over to the esprit 100. But to be honest for the 130PDS this is best unless you are willing to modify your focuser. https://www.firstlightoptics.com/astronomy-cables-leads-accessories/primaluce-lab-sesto-senso-v2-robotic-stepper-focus-motor.html Adam

the counter weight bar is a different diameter than the other SW mounts.

I think your reasonably safe with a doublet....its triplets, I see so many problems with them. I got my Esprit 100 new and had to swap it out, but even that was stressful, its allot of cash, even if the retailer was great about it. In the end the mount can be fixed. Adam

See my comment above.

He collected the scope in person.

The individual channels look good to me, not sure about the channel mapping at the end, seems like you got very little red in the image? BTW you are in the Observing section and not the imaging section. Maybe a @admincan move it into the imaging section? Adam

No, its not subjective. Stuff like clearly de-centered optics in a expensive triplet giving clearly bad stars and a mount with physical damage. I would not be at all bothered by cosmetic issues. Adam

I have recently had three incidents where myself or a friend have spent significant amounts of cash on used equipment and found the equipment to be faulty post purchase ~£3000 worth of gear in total. In each case it is clearly highly unlikely that the original owner was not aware of the issues associated with the equipment prior to sale and the issues could only be found in actual use as opposed to visual inspection. In each case all the appropriate questions where asked of the seller. Prior to saying anything else I will say that none of these items where purchased via SGL. I have sold many items of astronomy gear used via the forums and have always been as meticulous as possible in describing their condition within my advertisement. I even once sold a guide scope despite declaring the extensive scratches to the lens. Someone still purchased it and was happy with it, that is how you should go about things. So without naming any names, is this common? Have other people had similar experiences, have we been unlucky or should I just be buying all my kit new? What have you done when in this situation, did you try to return the equipment or suck it up and pay for it to be fixed? Adam

Skywatcher are bringing out their new evolux range soon, the 80mm might suit your needs for imaging.

yes but you will always get something as it only occurs for the steepest section of the light cone.

Are Chroma filters better than Baader, yes significantly so for the 3nm versions. But should you upgrade? That is purely a question of how deep your pockets are. Adam

Glad you posted this mate. Ill kick off with my interpretation. 1) I can see the star is pear shaped pointing downwards in the image. 2) You dont mention it but its very important to note that from memory rotating the focuser resulted in the distortion rotating relative to the camera and remaining fixed relative to the object being imaged. For me that rules out sensor tilt in the camera as a cause. I also know you have confirmed that the focuser is aligned using a laser colimator. 3) Its only visible when viewing the image at full size, so not the worst I have ever seen (some horrific star issues get posed on here) but still something is not right for a scope in that price range. I dont think that the flame is the best example of this as poor seeing has disguised the issue a little. The better example is M109 where you can see something is wrong even with the smallest stars. 4) I dont see anything obvious in the star test, although it might be worth re-doing with the star less defocused and with shorter exposures. I have seen some people use a guide camera and then stack the results as you would a planetary image to resolve more detail in the rings. Seeing can also effect the result. You are aiming for something more like this (my Esprit 100): Using a shorter exposure and in better seeing shows many more rings in more detail making it easier to judge collimation, 10 rings are visible or more. Although this is still probably more de-focused than is ideal. Something like a 0.05s exposure from my ASI1600mm pro, not sure what the min exposure is for your ATIK460EX, hence maybe use a guide camera. On the whole, from the shape I think it might be a case of pinched optics. But as you know I dont have sufficient experience of refactors yet to be sure or to rule out something like coma or a colimation issue. So hopefully someone else will be able to comment. Adam

Odd thing is that Chroma 5nm are more expensive than AD 5nm....and actually very similar in price to their 3nm...very odd.

Get a UVC bulb and shine it for a few hours onto the lens, it its fungus it will die if not then nothing lost hey.

The problem is that the 130PDS has a very low tube diameter and so virtually nothing fits it except for the moonlight as they made a special kit to allow it to be mounted. Most focusers available only fit tubes down to 6 inch Newtonian size. In so far as I have been able to find its the moonlight or nothing on the 130PDS.

Potentially the wrong drivers, if it thinks it has a 7 filter wheel when a 8 filter wheel is installed it will use the wrong number of steps between filters for sure. Check the driver and firmware load are correct for your camera.

Difficult choice I got to the point when I was thinking of either getting a moon light focuser or moving onto a refractor, in the end I decided it was a false economy to try putting a £300 focuser onto a £160 scope and saved for the refactor instead. The original focuser is fine for a DSLR or a OSC cooled camera, but by the time its having to hold a dedicated mono camera and a 8 position filter wheel it just cant hack it. The main issue is that you colimate with the light weight colimation tool in it and then the whole thing moves when you put the camera system on and hey presto your colimation is wrong.

Cleaner = 533 does not have a massive starburst amp glow pattern like the 294 does. Also the dark current is significantly lower on the 533 in comparison to the 294. All the charts are on ZWOs web page.

Really interested in how you get on with this reducer, any updates on spacing and high resolution images of the results would be fantastic.