A Noticeable Difference ?

[LDW1]

I replaced my 80mm, f6 refractor with a 90mm, f5.5 refractor because the price was right and its my style to try new gear, its my love in everything I do. From a viewing experience will I see much difference between 80mm-90mm ? The math indicates I may not but the build quality, the lens tinting may say otherwise. Maybe my Morpheus eps will show a difference ? My 3 zooms are getting restless, lol. They will both get their chance !   PS. I will post pics asap.

Edited March 17, 2022 by LDW1

[Davesellars]

Depends on a few other factors...

Was the 80mm an achromatic and the 90mm an ED doublet / triplet? or are they both achromatics?

The 90mm is a 25% increase in light gathering - this would be noticeable if you had tested both side by side on the same night and darkness.  For example if you've just looked through the 90mm at DSOs while the Moon is in play whereas the 80mm previously while there was none.. you can hardly compare the two.   I'd expect to see a difference in the same conditions especially if the 90mm has much better optics.

[LDW1]

6 minutes ago, Davesellars said:

Depends on a few other factors...

Was the 80mm an achromatic and the 90mm an ED doublet / triplet? or are they both achromatics?

The 90mm is a 25% increase in light gathering - this would be noticeable if you had tested both side by side on the same night and darkness.  For example if you've just looked through the 90mm at DSOs while the Moon is in play whereas the 80mm previously while there was none.. you can hardly compare the two.   I'd expect to see a difference in the same conditions especially if the 90mm has much better optics.

As I mentioned, they will both get their chance, side by side. I just received the 90mm yesterday am. Just waiting for a lack of clear skies in the last 2-3 months. By the way they are both achros.

[LDW1]

My 80mm and my new 90mm.

[RobertI]

I can’t really say how noticeable the difference will be, but please share your side by side comparison when you get around to it, should be interesting. 👍

[Stu]

Assuming they are similar optical quality, I’m sure you will see a difference. I’ve had many small fracs from 60mm to 100mm, and even the jump from say 76mm to 85mm is noticeable in terms of resolution and detail. I even noticed a little more detail in a 63mm Telementor vs a 60mm Tak, because in percentage terms even small mm increases make a difference down at those apertures. You wouldn’t notice going from a 200mm to a 203mm as a comparison though.