Yeah that’s a challenge, although I find a tiny Bahtinov mask works wonders
I'll give that a go, thanks Dunk.
Took a random test shot just pointing up roughly near zenith, no polar alignment, 30 seconds of Ha. Focus is not great (just adjusted until stars weren't big fuzzy blobs) but it contains a recognisable Cat's Paw, Lobster, Lagoon and Pipe Nebula. I'll call that success for tonight...
Took a random test shot just pointing up roughly near zenith, no polar alignment, 30 seconds of Ha. Focus is not great (just adjusted until stars weren't big fuzzy blobs) but it contains a recognisable Cat's Paw, Lobster, Lagoon and Pipe Nebula. I'll call that success for tonight...
A bit bummed out at present. Despite looking perfect on paper, the camera + EFW + Geoptik adapter doesn't seem to give the correct metal back distance. It clouded up before I could determine if the distance is too short and can be fixed with a thin spacer or to too long and I'm looking for a new adapter...
A bit bummed out at present. Despite looking perfect on paper, the camera + EFW + Geoptik adapter doesn't seem to give the correct metal back distance. It clouded up before I could determine if the distance is too short and can be fixed with a thin spacer or to too long and I'm looking for a new adapter...
Hmpff, spacing problems How much time do we spend getting that right ? Still, once sorted all good from there
The Geoptik Nikon adapter is too thick and the ZWO Nikon adapter is too thin. Will try the ZWO Canon adapter which looks closer to the expected dimensions and see how that goes.
First pic shows the pimped up Star Adventurer. Second pic is the view from our uppermost deck. Guess where the SCP is? Right behind the tallest tree
It’s odd that you’ve got all ZWO gear from camera to lens adapter and the spacings are that wrong. Not like you’re mix and matching anything. They didn’t send you the non-EFW version of adapter, did they?
It’s odd that you’ve got all ZWO gear from camera to lens adapter and the spacings are that wrong. Not like you’re mix and matching anything. They didn’t send you the non-EFW version of adapter, did they?
Yes, all ZWO stuff and it's definitely the EFW version. I can get the lenses to focus, but infinity is apparently only a few metres away. With a spacer of a couple of mm I can probably get it to work OK.
peter_4059 was kind enough to lend me some bits and pieces, including a couple of metal spacers that he machined himself. I'm getting pretty close now after quite a bit of experimentation.
The Geoptik Nikon adapter appears to be just too thick to work with my ASI1600 and EFW. In theory it should be the right size and it measures correctly, so perhaps the specs for the ASI1600 and/or EFW aren't accurate. The EFW measures correctly but I have no easy way of checking the camera back focus spec of 6.5mm (and it's not clear whether this includes an adjustment for 1/3 the thickness of the camera window and sensor cover glass).
The ZWO Nikon adapter looks workable but needs a thin spacer to get the lens distance correct. It may not be a coincidence that my adapter is actually a bit thinner than the specs say.
I also have a Canon adapter to play with if I can borrow a couple of suitable lenses.
How have you found the correction so far?
I’ve heard some conflictive reports as to its coma correction. As 50mm lens’ go it’s one of the best out there.
How have you found the correction so far?
I’ve heard some conflictive reports as to its coma correction. As 50mm lens’ go it’s one of the best out there.
Hi Colin,
I'm now using my Zeiss 100mm f/2 for testing. It has a manual aperture ring and a focuser designed for manual use. Once I get the spacing sorted out I'll go back to the Art 50mm.
M20 region with 100mm f/2 Zeiss lens. HaRGB: 30x30s Ha, 12x15s R/G/B (23 mins total). Captured from horrible inner Brisbane skies, so the colour data is especially awful:
Out of curiosity, does the spacing matter if it is still able to focus?
The spacing I have with my QHY163M is close but not perfect and I am curious as to whether I should be trying to get it exact.
Out of curiosity, does the spacing matter if it is still able to focus?
The spacing I have with my QHY163M is close but not perfect and I am curious as to whether I should be trying to get it exact.
There's a (thin) region where the field is flat and a region where you can get infinity focus. They overlap but they're not the same. But if you're getting good stars in the centre and corners at the same time I don't think there's any need to tweak further.