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help me pick a filter

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#1 shan1987

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Posted 02 April 2013 - 08:31 PM

so i have a 130/900 skywatch reflector on an eq mount that i just bought and I was looking around at what might improve views of some of the nebula i want to see (M42,M8,M17,M16,M27 M57 and M1) from what i learned there are several different kinds of nebula here and M1 is not so easy to find. It seems my best choices are a narrowband filter like Orion Ultrablock, Lumicon UHC, or Meade 4000 Broadband Nebular Filters OR a Oiii filter.. any advice?

#2 rdandrea

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Posted 02 April 2013 - 08:37 PM

If it's your first filter, DGM NPB. If it was going to be your only filter, I would make the same recommendation.

#3 StrangeDejavu

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Posted 02 April 2013 - 09:07 PM

I bought a DGM OIII as my first filter. It's usually $85, but it's on sale right now for $65. David K reviewed the filter, which can be found here.

I live in a white zone (heavy light pollution). My own research revealed OIII's are better for light polluted viewing since they do a better job of filtering out light pollution, where a NPB/UHC filter requires a dark sky site to really shine.

Since I only visit my dark sky site one night a month, OIII came first for me, and the DGM NPB will be my next purchase.

If you're interested in the DGM NPB filter, that review can be found here.

#4 shan1987

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Posted 02 April 2013 - 09:21 PM

thank you for your help...perhaps I should stop delaying the inevitable and by both now =)

#5 StrangeDejavu

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Posted 02 April 2013 - 09:47 PM

thank you for your help...perhaps I should stop delaying the inevitable and by both now =)


Anytime. If you have the cash, I definitely would. You can't beat $20 off. ;)

#6 VectorRoll

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Posted 03 April 2013 - 01:01 PM

thank you for your help...perhaps I should stop delaying the inevitable and by both now =)


Anytime. If you have the cash, I definitely would. You can't beat $20 off. ;)

I have been thinking a lot about getting a filter myself. I want to get a 2". I was thinking about the UHC myself but after reading your review I am not sure. I do live in a slightly light polluted area. It is not to heavy but still enough to mess with my views.

The thing that is stopping me from getting a filter right now is price. The DGM Filters sound nice but since I want to get a 2" the price is just out of my range right now. Even with there sale. :( I am definitely keeping them in mind for when I do get enough saved up. Maybe in a couple of more weeks. I hope they still have the sale going on by then.

#7 StrangeDejavu

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Posted 03 April 2013 - 01:24 PM

thank you for your help...perhaps I should stop delaying the inevitable and by both now =)


Anytime. If you have the cash, I definitely would. You can't beat $20 off. ;)

I have been thinking a lot about getting a filter myself. I want to get a 2". I was thinking about the UHC myself but after reading your review I am not sure. I do live in a slightly light polluted area. It is not to heavy but still enough to mess with my views.

The thing that is stopping me from getting a filter right now is price. The DGM Filters sound nice but since I want to get a 2" the price is just out of my range right now. Even with there sale. :( I am definitely keeping them in mind for when I do get enough saved up. Maybe in a couple of more weeks. I hope they still have the sale going on by then.


Just to be clear, all credit for both reviews belongs to our own David Knisely. :)

#8 tnakazon

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Posted 03 April 2013 - 02:41 PM

First, congrats on getting a 130/900 reflector! I do my observing with telescopes of smaller aperture (4.5" or less), but the one and only time I used my 130mm/5.1" aperture scope away from serious light-polluted skies, it was a revelation. You can start doing some serious deep-sky observing with a scope of this size, especially outside the city.

I also agree with the previous post that in really light-polluted conditions, the OIII filter will perform better in detecting emission and planetary nebulae than a narrowband. I own and use all 3 - broadband, narrowband, and OIII. Again, refer to David Knisely's excellent article on how different nebulae look these three types of filters + H-Beta filter.

#9 David Knisely

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Posted 03 April 2013 - 03:06 PM

I bought a DGM OIII as my first filter. It's usually $85, but it's on sale right now for $65. David K reviewed the filter, which can be found here.

I live in a white zone (heavy light pollution). My own research revealed OIII's are better for light polluted viewing since they do a better job of filtering out light pollution, where a NPB/UHC filter requires a dark sky site to really shine.

Since I only visit my dark sky site one night a month, OIII came first for me, and the DGM NPB will be my next purchase.

If you're interested in the DGM NPB filter, that review can be found here.


I still recommend the NPB filter over the OIII as the "first" filter, especially for smaller scopes. Its wider passband allows more star light to get through and will help the new user get used to viewing in the darker field of view that filters will provide while still rejecting enough skyglow to improve the nebulosity. There are also some objects that have enough H-beta emission that using an OIII might actually hurt their appearance, so a narrow-band filter may be a better choice. After using the NPB for a while, the observer will want to get a good OIII filter, especially for objects like small planetary nebulae where the "blinking" finding technique can prove very useful. The original poster also mentions wanting to see M1 and for that object, a narrow-band filter like the NPB is notably more effective than the OIII is. Clear skies to you.

#10 ubermick

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Posted 03 April 2013 - 03:11 PM

I was on the verge of getting a Lumicon UHC, but at DGM's prices I was able to snag an NPB *AND* an O-III for about the same price. (Free shipping from DGM, $10 from Lumicon).

I'm quite peeved at Lumicon, actually. Ordered one of their variable polarizing filters from their site on the same day as the filters from DGM. one week later (a few days after my DGM's arrived) I get an email from Lumicon telling me that those filters are actually backordered, and they'd ship it out as soon as it was available. Replied to that email, mentioning that at no place on their site did it say that any of their filters were unavailable, and asking when I could expect it. One week later, I have yet to get a response...






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