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APM 2" Barlow 1.5x

APM APMBarlow2 Barlow Troubleshooting
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eric belanger avatar
eric belanger avatar
Hello . If anyone is using this Product . I need help ! 
APM 1.5x Barlow telecentric for Visual and astrophotography. I have the backfocus right....(i think) but cant see any stars or trees because i tried during daytime also . The focuser tuber went back and Forth trying to focus but Never saw anything .

Just need help 
andrea tasselli avatar
andrea tasselli avatar
Are you sure you have enough inward travel to reach focus? Test the barlow with an EP and see whether you can reach focus. If you can and then move in and out of it there should be enough focus travel to reach focus with the camera too.
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Oscar avatar
Oscar avatar
IMO

to make sure whether you need inward or outward travel to solve your problem:

I suggest you loosen the thumbscrews on the focuser, remove the 1.5x barlow (with your image train intact), and move your imaging train outwards slowly, even out of your focuser if necessary, to see if anything comes into focus then

if it does, then you need more outward travel to solve your problem, if it doesn't, you need more inward travel
eric belanger avatar
eric belanger avatar
Thanks for the suggestions.

Andrea , what Do you Mean with testing the Barlow with an EP ? What EP stand for ? Thank you
andrea tasselli avatar
andrea tasselli avatar
eric belanger:
Thanks for the suggestions.

Andrea , what Do you Mean with testing the Barlow with an EP ? What EP stand for ? Thank you

*An eyepiece. If as I suspect the scope is a SW newton then you might have had one if you bought it new.
eric belanger avatar
eric belanger avatar
Ok …so i just had to Take the coma out by about 2 inches. Now …. it's a very long optical train so i Will have to add a screw to tight the coma well . To avoid flex.
​​​​​​Thanks all smile
Oscar avatar
Oscar avatar
eric belanger:
Ok ...so i just had to Take the coma out by about 2 inches. Now .... it's a very long optical train so i Will have to add a screw to tight the coma well . To avoid flex.
​​​​​​Thanks all

does the 1.5x barlow have any 2" filter thread? if it does, you can try adding an M48 spacer to that so it's more secure in the focuser
Gábor Galambos avatar
Gábor Galambos avatar
In order to get focus, you need to move the APM 2" Barlow 1.5x corrector about 3 cm away from the focuser. I use the APM 2" Barlow 1.5x corrector for Lacerta 200/800 photonewton. For the Lacerta Octo Plus 2 focuser, I use the screw spacer shown in the attached picture (3 pieces, which are 3x12 mm).
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Werner Stumpferl avatar
Werner Stumpferl avatar
Hi Eric,
as far as I know, the APM has a working distance of 95mm not 105 (source TS) ?

CS
Werner