D-ERF right direction

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Geremia Forino
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D-ERF right direction

Post by Geremia Forino »

Hello Solar firnds,

just received my Baader D-ERF from ventors and I am a bit confused on the direction to adopt in the cell, if I remember correctly, the "V" engraved on the Corrector of an SCT indicated the direction towards the primary, in this case what should the direction be, Sun Or telescope?
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Re: D-ERF right direction

Post by marktownley »

Hi Geremia,

See my review of the Baader DERF - the arrow points towards the sun.

Mark

https://brierleyhillsolar.blogspot.com/ ... eview.html


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Re: D-ERF right direction

Post by LTHB »

On their webpage Baader says (unfortunately in German only) that the "V" is meant to be an arrow, and the arrow must point in the direction of the sun.

https://www.baader-planetarium.com/de/d ... filter.pdf

Frank


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Re: D-ERF right direction

Post by Geremia Forino »

Mark during a google search I saw this blog, I did not know it was yours, congratulations for the description.
as you can see you have a arrow, I have a "V" the confusion remained as I was referring to the optics of a SCT.

Thanks Frank to confirm the direction it points towards the Sun.


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Re: D-ERF right direction

Post by Simon2940 »

If ever in doubt, if you hold something like a screwdriver or pen over the filter, if you see an infinity reflection of the item, that is what faces the sun.

If you only see 2 or 3 faded reflections (or even just 1 reflection), that side faces the scope.


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Re: D-ERF right direction

Post by Geremia Forino »

If Simon has not been wrong, I am right, the "V" must point the telescope, just like in the SCT corrector.....I'm confused :?


Single Reflection
Single Reflection
single reflection.jpg (2.66 MiB) Viewed 2249 times
Multiple Reflection
Multiple Reflection
multiple reflection.jpg (2.65 MiB) Viewed 2249 times


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Re: D-ERF right direction

Post by Simon2940 »

Ive always understood it as the multiple reflections should not be pointed at the sensor, otherwise when imaging, these reflections will be seen.

One side is a multilayer coating and the other is anti reflective.

I know this image is extremely confusing but hey, i could be wrong.
post-232700-0-54695200-1512502294.jpg
post-232700-0-54695200-1512502294.jpg (62.56 KiB) Viewed 2234 times
To be sure, go by what the instructions say. According to the PDF, the arrow points towards the sun.


Geremia Forino wrote: Tue Mar 29, 2022 10:15 pm If Simon has not been wrong, I am right, the "V" must point the telescope, just like in the SCT corrector.....I'm confused :?



single reflection.jpg

multiple reflection.jpg


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Re: D-ERF right direction

Post by Simon2940 »

I just triple checked with an ERF that's already mounted, the arrow pointing TOWARDS the sun meaning that the multi reflection faces the scope (or camera). Im assuming a D-ERF is treated as narrowband filter which makes sense since its only allowing 600-700nm.

I was wrong. The mentioned is true for LRGB.


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Re: D-ERF right direction

Post by Geremia Forino »

Thank you for checking Simon, this reassures me


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