Ichthyosaurs

Thanks, have bought an extension kit and will try tonight if skies remain clear

1 hour ago, fwm891 said:

I have a ZS73 with the flat73A field flattener. Spacing is quite critical  from the back of the flattener to the sensor. You don't say which flattener or what camera your imaging with. A DSLR (Nikon, Canon etc) need the spacing set to 11.4? on the flat 73A along with their respective T adapters. Non DSLR's will probably need  various extensions to obtain a flat field

WO page: https://williamoptics.com/new-adjustable-flat73-for-z73   scroll down until you see the spacing details...

Thanks Guys, flattener is the non adjustable dedicated william optics for zs73, i thought this was already at 55mm when i attached my camera an Altair Hypercam 294C PRO, will check distances tonight, another lesson learned.

Hi All

I have  a ZS73 which i use purely for astrophotography, when i first started i wasnt worried about the egg shapes at the perimeter but as i have progressed and gotten better with guiding i bought a wo dedicated flattener but i am disappointed that this has no real effect on my photos. Below is a widefield picture of the owl nebula using the 1:1 wo zs73 flattener, eggs all around the perimeter, is this a collimation problem any advice welcome.

Thanks Matt, appreciate your comments.

Currently using a WO ZS73 doublet for astrophotography, gives great wide field views and is going to be a keeper whatever else I do. I am going to buy a triplet and the 2 I am currently looking at are a new WO GT81 on offer at FLO for £995 and a used Altair Astro 115 triplet at £1275 on ABS. Primarily to be used for DSO astrophotography, comments from anyone who has experience with either welcome. Thanks in advance.