TechTalk
Well-known member
I haven't read any reviews which assert aberration-free wide open imaging with the XCD 25V, but the reviews which suggest coma is minimized and well controlled with some astigmatism present appear to be accurate from the images I've seen so far. The astrophotography website Lonely Speck has a guide to lens aberrations and their appearance in night sky photography which I've linked below for those interested.So how much coma is too much? There are finally some stars visible, and that left side is showing its oddities. I mean, the first day's shots didn't magically get better - I just found that for what I usually do, it didn't matter. Now I don't do astro, but the reviews of this lens's aberration-free wide open imaging had me curious. What will show up at night?...
www.lonelyspeck.com/A Practical Guide to Lens Aberrations and the Lonely Speck Aberration Test