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filter position??

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#1 gonzosc1

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Posted 10 December 2012 - 10:56 PM

where is the best position to place a filter. in the eyepeice, barlow, in front of dia.???

#2 Hikari

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Posted 10 December 2012 - 11:29 PM

It does not really matter. The eyepiece tends to be the smallest diameter and so the cheapest filter. I used to use a 2" to 1.25" adapter and I would put 2" contrast filters in the adapter so I could switch between 1.25" Eps and not have to change the filter each time.

#3 Danzup77

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Posted 11 December 2012 - 12:35 AM

I throw em on the bottom of the EP simply for ease of access if I want to change to another.

#4 gonzosc1

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Posted 11 December 2012 - 04:32 PM

ok thanks. I was just thinking about the older meade sct threaded filters and wondered if it made a difference.
thinking about getting the broadband sct meade filter for my c9.25. as I'm in the city limits it would be used almost 100% of the time. maybe add an oxy-II filter in 1.25 format down the road...

#5 killdabuddha

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Posted 12 December 2012 - 10:49 AM


If usin Orion, wherever it'll thread best. Our Ultrablocks stay on the 36mms cuz it's a pain to get them on anywhere. And the moon filters we just stack inside the stars for use, without even threading.

#6 Starman1

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Posted 12 December 2012 - 03:53 PM

ok thanks. I was just thinking about the older meade sct threaded filters and wondered if it made a difference.
thinking about getting the broadband sct meade filter for my c9.25. as I'm in the city limits it would be used almost 100% of the time. maybe add an oxy-II filter in 1.25 format down the road...

The "thread on the back of the SCT" filters are a true pain, because you WON'T use the filters all the time.
A broadband filter can make a VERY slight difference on some galaxies, but, by and large, it is only nebulae that are helped by restricting the bandwidth, and a narrowband filter works MUCH better to enhance nebulae.
You probably won't use a filter at all on star clusters or galaxies.
Meade hasn't sold nebula filters for years, and IIRC, their older broadband wasn't a very effective filter, even for a broadband, compared to specialty filters like Thousand oaks, Lumicon, and Orion.

If you buy just one nebula filter, it should be a good narrowband filter that transmits the H-Beta and O-III lines in the spectrum.
Later on, you can get a more specialized Line filter, like a good O-III filter, for planetary nebulae or specific emission nebulae enhanced by such a filter (like Thor's Helmet, or The Veil).

If you thread it onto the diagonal, you can change eyepieces without swapping filters. Just keep in mind that all these filters work best at low power (<100X), so you may only have one or two eyepieces you'll use with it.

As for enhancing galaxies and star clusters, the best filter is gasoline--you put it in your car and drive the scope to darker skies. :grin:

#7 gonzosc1

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Posted 12 December 2012 - 07:57 PM

ok thanks. I was just thinking about the older meade sct threaded filters and wondered if it made a difference.
thinking about getting the broadband sct meade filter for my c9.25. as I'm in the city limits it would be used almost 100% of the time. maybe add an oxy-II filter in 1.25 format down the road...

The "thread on the back of the SCT" filters are a true pain, because you WON'T use the filters all the time.
A broadband filter can make a VERY slight difference on some galaxies, but, by and large, it is only nebulae that are helped by restricting the bandwidth, and a narrowband filter works MUCH better to enhance nebulae.
You probably won't use a filter at all on star clusters or galaxies.
Meade hasn't sold nebula filters for years, and IIRC, their older broadband wasn't a very effective filter, even for a broadband, compared to specialty filters like Thousand oaks, Lumicon, and Orion.

If you buy just one nebula filter, it should be a good narrowband filter that transmits the H-Beta and O-III lines in the spectrum.
Later on, you can get a more specialized Line filter, like a good O-III filter, for planetary nebulae or specific emission nebulae enhanced by such a filter (like Thor's Helmet, or The Veil).

If you thread it onto the diagonal, you can change eyepieces without swapping filters. Just keep in mind that all these filters work best at low power (<100X), so you may only have one or two eyepieces you'll use with it.

As for enhancing galaxies and star clusters, the best filter is gasoline--you put it in your car and drive the scope to darker skies. :grin:


thanks for the tips starman. my problem is I have a c9.25 so I have to use the sct dia. the only way to get a filter in front of it would be the sct filter. I see that lumicon makes those filters also for the sct threads..

having trouble this is filter thing! I guess I could go with a 2" on the eyepeice or barlow when used. but I'm also using BV's so I'm trying to figure out where to put the filter so I can use it with everything! kind of the best of both worlds dream...

#8 Starman1

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Posted 12 December 2012 - 08:44 PM

An SCT doesn't have to use a thread-on diagonal. They sell tubular adapters that thread on the scope so a slip-fit diagonal can be used. Most 1.25" SCT diagonals are like that, and 2" can be obtained that are the same.
But if you have a thread-on star diagonal, your best bet is a filter that threads to the eyepiece or, in your case, the front of the binoviewer.
Note than many 1.25" to 2" adapters are threaded on the front for 2" filters. So if your adapter is so threaded, a 2" filter would be a "universal" filter because it would thread on 2" eyepieces and the 1.25" adapter into which 1.25" eyepieces (or binoviewer) is inserted, exercising care the front end of the eyepiece or BV doesn't hit the filter. If it does, it's a simple matter to obtain a longer adapter.

#9 gonzosc1

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Posted 12 December 2012 - 09:25 PM

An SCT doesn't have to use a thread-on diagonal. They sell tubular adapters that thread on the scope so a slip-fit diagonal can be used. Most 1.25" SCT diagonals are like that, and 2" can be obtained that are the same.
But if you have a thread-on star diagonal, your best bet is a filter that threads to the eyepiece or, in your case, the front of the binoviewer.
Note than many 1.25" to 2" adapters are threaded on the front for 2" filters. So if your adapter is so threaded, a 2" filter would be a "universal" filter because it would thread on 2" eyepieces and the 1.25" adapter into which 1.25" eyepieces (or binoviewer) is inserted, exercising care the front end of the eyepiece or BV doesn't hit the filter. If it does, it's a simple matter to obtain a longer adapter.


Starman, you are the man!!. lol never looked at the bottom of the 1.25 adapter for the 2" threads.. :foreheadslap: and there they are! thanks, I'd buy you a 6 pack if you were not 1800 miles away.... :bow: :bow: :bow:

#10 Waldemar

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Posted 13 December 2012 - 03:35 PM

I'd buy you a 6 pack if you were not 1800 miles away.... :bow: :bow: :bow:


Tha postman is Santa's right hand, didn't you know? :jump: :roflmao:






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