Vixen Astrograph

[Scott]

10 hours ago, steppenwolf said:

As Tim has stated and my own review confirms, the flat field characteristic of this instrument is phenomenal but on the example we had to test there was an issue with colour. I don't keep my test images forever, only those that I like and then place on my website or use when giving talks so I don't have my OSC test samples any more. However, I did like the results achieved in narrowband which is an area where this telescope can excel. The image below is a bi-colour captured using the telescope and it demonstrates the flat field quite well.

The focuser was beautifully crafted and could be motorised by a belt drive but it does require very small movements as the depth of field is very shallow at f3.8. I have no explanation for why Ninian didn't find the same issue as the problem of green/yellow versus red/blue focus was acknowledged by the manufacturer at the time of my review but perhaps they have made a change to the optics? I hope this is the case as it would turn a killer narrowband instrument into a killer wide field instrument for all wavelengths.

Bi-colour Narrowband image of the Veil Nebula captured with the VSD 100 and a QSI WSG-8

 

It's good, but it's no esprit

[Tim]

It is quite telling that both Steve and I were worried that our results were erroneous, despite find the same thing completely independently with no correspondence. I went to great lengths to try and prove myself wrong, i really did I had the luxury of just declining to put a review out, but poor Steve had the S@N commission and a deadline and had to put his name to it. When he phoned I think he was relieved that my cameras had told the same story. Very expensive telescope, very respected producer....... it is a lot of pressure!

 

[ollypenrice]

9 hours ago, Tim said:

It is quite telling that both Steve and I were worried that our results were erroneous, despite find the same thing completely independently with no correspondence. I went to great lengths to try and prove myself wrong, i really did I had the luxury of just declining to put a review out, but poor Steve had the S@N commission and a deadline and had to put his name to it. When he phoned I think he was relieved that my cameras had told the same story. Very expensive telescope, very respected producer....... it is a lot of pressure!

 

Indeed. We are a part of a small community and reviewers know that they have a responsibility to their fellow members of that community. It is very difficult to get reviews dead right for various reasons, not least of which is variability in product quality control. Another can be rapid wear in mechanical parts, meaning that a product you approve during a test can prove to have a short service life, and so on and on.

Olly

[Davey-T]

Going by the glowing revue in AN folk may be tempted to buy one, well rich folks anyway 

Dave

[Mr Spock]

Sounds like a champ with a glass jaw. Bit of a shame really.