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Hutech IDAS LPS-D2 Nebula filter for Mono?


ebdons
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Hi, Thankyou for the info, I'm torn between the D2 and P2 as I have led lights near me and maybe I need to decide whether to go mono or OSC? other opinions say D2 will be best as I can use it for the Luminance channel in RGB? but they have cmos sensors and not ccd sensors like my cams have ie qhy10 and sx825M. but I still can't make my mind up! Ton

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2 minutes ago, ebdons said:

Hi, Thankyou for the info, I'm torn between the D2 and P2 as I have led lights near me and maybe I need to decide whether to go mono or OSC? other opinions say D2 will be best as I can use it for the Luminance channel in RGB? but they have cmos sensors and not ccd sensors like my cams have ie qhy10 and sx825M. but I still can't make my mind up! Ton

No difference in filter use between CCD and CMOS, or at least there should be none. It can happen due to very specific reasons that some combination will not work as expected (narrow band filters predominantly) - usually down to reflections that can happen between components, but other than this - same filters can be used both on CCD and CMOS sensors.

Don't know about D2, I only used P2 so far and I'm very pleased with it. My LP is really very mixed - all sorts of light sources - incandescent, LP/HP sodium, maybe even some LEDs (but nothing on major scale like street lighting - more in use for security / porch lighting in the neighborhood) and P2 helps quite a bit with that.

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Hi excellent info! I have led street lights near me well 100yds approx., and sodium lamps as well, just trying to get my choice right as it's quite an investment, as I have astronomic UHC and CLS as my main LP filters but know that IDAS are the best out there? so folks say? Ton

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4 minutes ago, ebdons said:

Hi excellent info! I have led street lights near me well 100yds approx., and sodium lamps as well, just trying to get my choice right as it's quite an investment, as I have astronomic UHC and CLS as my main LP filters but know that IDAS are the best out there? so folks say? Ton

That was my impression as well when I did research into which one to buy. It's held in high regard, and I would have to say, probably rightfully so. I have not tried some other LPS filters out there. I just had opportunity to work with UHC and CLS (low cost plain ones), and IDAS is quite a bit different than those. CLS and UHC are very restrictive filters - they cut out too much light. IDAS P2 just filters very small sections of spectrum where most of LP is concentrated. Color balance is the least affected for example. I now have both 1.25" and 2" version of P2 - I used 1.25" for L with mono, but soon realized that R, G and B also need filtration to improve SNR and reduce gradients (hence need for 2" so it can be combined with 1.25" color ones).

I now have no use for CLS (and I think I gave away two of them). UHC I still find useful - mostly for visual, but it can also be used for AP depending on target. I would probably use UHC over P2 if I was going for emission target with OSC camera - UHC will pass all important emission lines (Ha, OIII, NII, SII) but cut stronger into LP.

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Hi, thankyou for that explanation, I'm using my UHC now on the bubble neb in Cepheus and it's coming out well in mono, altho the QHY10  likes the CLS for anything faint etc, I think the D2 is the one to go for? a worthwhile investment for me as I don't have the option at the moment to travel to a DS site. Ton

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Remember that you lose more singnal than you gain. Most of RGB filters allready clip out the most common light polution source.

 

Might give some contrast to nebulas. But for galaxy's lp filters just clip out too much light coming from galaxy. 

 

Jon at CN has proven also blurring efect of idas filter's. 

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5 minutes ago, JukkaP said:

Remember that you lose more singnal than you gain. Most of RGB filters allready clip out the most common light polution source.

 

Might give some contrast to nebulas. But for galaxy's lp filters just clip out too much light coming from galaxy. 

 

Jon at CN has proven also blurring efect of idas filter's. 

It's not about the signal it's about SNR :D

Removing some of the light from the target may seem like a bad thing, and it would be if there was no LP involved. You would be lowering your signal but doing nothing to noise part of the equation.

On the other hand when there is a lot of LP, removing some of the signal from the target is worth if you remove a lot of noise associated with LP. Overall signal to noise ratio will improve in the process.

Could you provide link to thread on CN where blurring effect of IDAS filters is discussed?

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The SNR part is true, If you look just the background. But if you look the snr of your target(mainly galaxy) it might not be so simple. 

I dont know what is the truth. But based what I have read I would not use lps filter whit LRGB filters.

Whit DSLR, shooting HA target, I think I would still use lps filter.

Shooting galaxy whit any equipment I would not use lps filter.

 

Here is the topic. There is more spesific topic also, but could not find it. Look at the page 2 whit good comparison image.

https://www.cloudynights.com/topic/573267-light-pollution-filters-for-luminance-broadband-targets/

 

 

 

 

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11 minutes ago, JukkaP said:

The SNR part is true, If you look just the background. But if you look the snr of your target(mainly galaxy) it might not be so simple. 

I dont know what is the truth. But based what I have read I would not use lps filter whit LRGB filters.

Whit DSLR, shooting HA target, I think I would still use lps filter.

Shooting galaxy whit any equipment I would not use lps filter.

 

Here is the topic. There is more spesific topic also, but could not find it. Look at the page 2 whit good comparison image.

https://www.cloudynights.com/topic/573267-light-pollution-filters-for-luminance-broadband-targets/

 

 

 

 

Huh, I'm seeing the image, but I'm not totally convinced about this blurring effect. Difference is too small and can be contributed to number of reasons.

Primary candidate is length of single exposure. No mention of mount used, and guiding performance. Stacking more shorter subs improves FWHM (there is align in frames after each frame - shorter exposure - more frames - more frequent align).

True comparison if one is going to use different exposure lengths to compare FWHM would be to stack without aligning at all - just average of frames and look at FWHM. In that case we could say that guide error is averaged over total duration and only unknown would be changing seeing - which can sway either way.

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I read long about the LRGB imaging whit mono camera. I found multiple references that the lps filter is increasing fwhm.

I have no coin is this. I have happily shoot whit idas-lps-d1 for 4 years using DSLR.

 

I have been able take good pictures whit it, but I honestly belive when you work whit mono camera and RGB filter(that allready cut the sodium light polution out) The lps only adds one reflective layer of class in your image train. For LED light polution the lps filters are not the solution.

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Hi All, thanks for the info about this, I still have doubts about IDAS and reading about blurring on faint objects, true or not? seen a skytech LPRO MAX which I think is the same as the Omegon filter?  some folks love them? and still not sure if my LP can be overcome? I will keep looking into it? Ton

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