Using a Riccardi reducer

Started 2 months ago | Discussions thread
Michael S.
Michael S. Veteran Member • Posts: 8,242
Re: Using a Riccardi reducer

elgol20 wrote:

Michael S. wrote:

elgol20 wrote:

hi michael,

with filter I need to add about 1/3 of the optical thickness which is 0.7mm which should not be neglected when accuracy must be less than 0.5 as I understand. even though doing this stars are a bit elongated so now trial&measure will follow. yes, even 0.1mm rings are available which made me wonder. the esprite is really nice. due to wheight and transportability I opted for the 2nd largest. f/7 though made me hesitate first

Hi Stefan!
Don't forget with smaller sensors it will be easier. Full frame will be a challenge and you may not get 100% round stars in all 4 corners, you'll always some tilt, but APS-C and above it should not be much of a challenge.

best regards,

hi michael, here is a testshot done under bortle8 sky thus using lenhance filter (ok, next time I will leave it away but downtown is too much light) on fullframe nikon d810a

Ok...that quite strong filter suppresses many stars, but what can be seen in the four corners is that those are very symmetrical, does not seem like you have a tilt, that's very good. As I can see slight "spaghettis", so a little change in the distance may help.

best regards,

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Michael S.
EUROPE; dpreview since 2001
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 Michael S.'s gear list:Michael S.'s gear list
Leica SL2 Nikon D610 Nikon D5300 Nikon D810A Leica M10-P +6 more
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