Altair flattener/reducer backfocus

[DainiusU]

Hi,

 

I have just got a new flattener/reducer and want to measure the backfocus for my Canon DSLR. Any ways to do it without taking clear sky pictures?

 

thanks for any ideas!

[Anthonyexmouth]

47 minutes ago, DainiusU said:

Hi,

 

I have just got a new flattener/reducer and want to measure the backfocus for my Canon DSLR. Any ways to do it without taking clear sky pictures?

 

thanks for any ideas!

just attach the FF/R to the T Ring. that's all thats needed. 

Edited October 4, 2019 by Anthonyexmouth

[Craney]

As above, I think it is set for  the standard DSLR  backfocus distance  of  55mm. 

[michael8554]

Just to avoid any misunderstanding, Canon backfocus is actually 44mm, and a T-ring adds 10 to 11mm.

Michael