Yeah, there is a little obvious CA, at least on my monitor, but , what is important , is if it makes you happy?
Hey, it is an achro,...achromats aren't magical......it is all about the physics...
I had an ISTAR 100/1200 one time, it was "alright".
Little over 1/4 wave, I paid 300 for the objective in cell with shipping.
I sold it for 200 shipped, what I figured it was actually worth.
I bought off the web site , which had an objective with a test report of 1/6th or close as an advertisement of the quality of the objective I was to receive.
Yes, I was disappointed that what I received was not what was advertised.
Was the objective I bought a "good" objective? Yes, I believe so.
Was it a "killer ' objective? No
Can one see the difference between a measured wavefront of 1/4 and 1/6th at the eyepiece? Yes.
Was I about to send it back and complain because I didn't get what I expected to receive?
No, because I don't have the time to play those kind of games. My curiosity has been satisfied.
I sold it with full disclosure of the interferometry report. I am sure the new owner is enjoying the glass and he got a "deal".
Another observer and I actually did a compare between the ISTAR 100/1200, the Carton 100/1300 and a Jaegers 103/1575. All in home-brew OTAs. Simple compare..Saturn. The Jaegars won.
Draw your own conclusions.
Thank you for your report. It's a pity that the objective wasn't 1/6 wavelength. You probably had bad luck
How was the CA comparing the Istar 100/1200 with the Carton 100/1300?
Saturn isn't a perfect object for comparing the CA but better than no comparison