#1  
Old 15-11-2021, 10:58 AM
LewisM's Avatar
LewisM
Novichok test rabbit

LewisM is offline
 
Join Date: Aug 2012
Location: Somewhere in the cosmos...
Posts: 10,388
The stupid question regarding filters

Does it make any difference if a filter is mounted backwards to usual orientation? I have a Tak adapter that presents an m48 filter thread on the rear of the adapter meaning the filter gets screwed on bass-ackwards.

Does it make any difference (it’s going to hold a UV/IR cut filter) or since the light will be going through it anyway won’t make a jot of difference.

If it does I’ll just get a custom one made
Reply With Quote
  #2  
Old 15-11-2021, 11:21 AM
multiweb's Avatar
multiweb (Marc)
ze frogginator

multiweb is offline
 
Join Date: Oct 2007
Location: Sydney
Posts: 22,060
Quote:
Originally Posted by LewisM View Post
Does it make any difference if a filter is mounted backwards to usual orientation? I have a Tak adapter that presents an m48 filter thread on the rear of the adapter meaning the filter gets screwed on bass-ackwards.

Does it make any difference (it’s going to hold a UV/IR cut filter) or since the light will be going through it anyway won’t make a jot of difference.

If it does I’ll just get a custom one made
Unless there is an anti reflection coating on one side only it shouldn't matter.
Reply With Quote
  #3  
Old 15-11-2021, 11:26 AM
LewisM's Avatar
LewisM
Novichok test rabbit

LewisM is offline
 
Join Date: Aug 2012
Location: Somewhere in the cosmos...
Posts: 10,388
Just been informed there is a filter adapter in the inside end of the draw tube so cool beans
Reply With Quote
  #4  
Old 15-11-2021, 11:46 AM
JA
.....

JA is offline
 
Join Date: Oct 2016
Location: Melbourne, Australia
Posts: 2,945
Quote:
Originally Posted by LewisM View Post
Does it make any difference if a filter is mounted backwards to usual orientation? I have a Tak adapter that presents an m48 filter thread on the rear of the adapter meaning the filter gets screwed on bass-ackwards.

Does it make any difference (it’s going to hold a UV/IR cut filter) or since the light will be going through it anyway won’t make a jot of difference.

If it does I’ll just get a custom one made
Hi Lewis,

It can make a difference as Marc has already said, but if it ever becomes an issue for any filter you'd like to use you can VERY carefully unscrew or unclip the filter retaining ring on the filter assembly itself and invert the filter inside its holder. I have done that for a different reason on some Nikon 39mm threaded filters that I wanted to convert to use 36mm unmounted astro type filters.

I do recall an issue once raised to do with the "directionality" of some early ZWO filters

Best
JA
Reply With Quote
  #5  
Old 15-11-2021, 12:24 PM
Stonius's Avatar
Stonius (Markus)
Registered User

Stonius is offline
 
Join Date: Mar 2015
Location: Melbourne
Posts: 1,495
The way to tell is to hold something near the filter and observe the reflection in the filter. If one side gives you a double reflection and the other gives you a single reflection, the filter is directional.


Cheers,


Markus
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 11:21 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Advertisement
Bintel
Advertisement
Testar
Advertisement