Optolong L-Quad Enhance Filter Review

The Optolong L-Quad Enhance filter has been designed to block light pollution while photographing broadband targets. This sets it apart from the L-Enhance, L-Ultimate, and L-Extreme, which are all built for narrowband nebulae photography in light polluted areas. Therefore, if you had an L-Ultimate and an L-Quad Enhance filter you could (theoretically) photograph any object you want from a light polluted area.
In this video I'll share my experience with the filter over the past few months (although we only had about 4 clear nights total!) Most of these tests were performed in my backyard, which is a Bortle 4.5. The other two tests were conducted in Bremerton, Washington which is a Bortle 6/7.
Each night I would bring out two nearly identical camera rigs for these tests. Rig #1 had a RedCat 51mm, ZWO AM5, ASIAir Plus, and ASI 2600MC with no filter. Rig #2 had a SpaceCat 51mm, ZWO AM5, ASIAir Mini, and ASI 2600MC Duo with the Optolong filter. This allowed me to keep the testing environment very precise. Same night, same exposure time, and nearly the same gear.
The processing was identical between photos as well. I started off with BlurXterminator - Correct Only to fix any star distortion. Then I used SPCC to fix the color cast. I ran BlurXterminator again, this time to sharpen up the data. Next I ran StarXterminator, and finally BackgroundNeutralization (on some of the images). This should give us a clear view of the data for the comparison.
Unfortunately I did not capture much data for any of the 6 targets. Ideally I would have at least 4 hours per target, if not 8 or 16 hours. However, this is just not feasible with the weather we've been having this winter. I'd recommend watching the following review video from ‪@intergalacticastro‬ to see how more data can improve the final images taken with the L-Quad Enhance Filter:
• Optolong L Quad Enhanc...
Feel free to inspect the all master XISF files straight out of WBPP here:
u.pcloud.link/publink/show?co...

[@himalaYAK1983]

Your videos are among the absolute best in the astrophotography community. Thanks for this review!

[@Xiaotian_Guan]

Not surprised. The problem with any of these broad band light pollution filters is that they only reject Hg and Na lines. With more and more lighting moving to broad band light sources like LEDs, they become pretty much useless

[@Zealor365]

Hey Peter, I'm in downtown Bremerton and find that the L-Quad does not perform to my expectations from my back yard. I can shoot with the L-Extreme and results are superior. Keep up the good work!

[@Xu.123]

Antlia triband is better. Second version will come out soon.

[@markstanford2315]

Yes, someone once said that the best LPR filter is a tank of gas!

[@woody5109]

Wow, this is an eye opener, great review.

[@viewintospace]

Thanks Peter for being so honest.

[@intergalacticastro]

Thank you for sharing my Optolong L-Quad Enhance Filter Review I appreciate it.

[@dh2970]

Very informative, great explanations, thanks!

[@keyswitches9269]

that thumbnail is so good!!

[@drkumarharaprasadmisra5562]

I am From Bortle 4-5 . I shoot this filter with Samyang 135 and 533mc pro. I have very good results both for broadband targets and Narrowband Target.

[@AmatureAstronomer]

Thinking of buying one of these. Oh, and just subscribed.

[@deepskytrekkin9600]

My backyard is Bortle 4. Some sky glow from 30k pop. cities nearby. I am using the quad (with ASI294MC Pro) with good results. Even during full moons +/- a few days. My two cents worth is too make the comparison with at least 5+ hours of time on a target. I suspect that is all that is needed for the quad's performance to pull away from the 'no filter' images. The quad has made a BIG difference in the quality of my images. I use either 3 or 5 minute subs for stacked totals from 5 hr. to 14 hrs.

[@mikehardy8247]

Thanks! I'm not buying it, as I'm in bortle 8-9. Just watched a few Cuiv videos on filters. "Think " I'm getting an idea of which filters will give me good results. An honest evaluation like this is very helpful.

[@DoktorApe]

Non-narrowband light pollution filters are basically obsolete due to adoption of LED lighting, which has a more broadband emission spectrum than mercury or sodium lamps. (I googled about Bremerton and turned up a city document requiring installation of LED street lights...)

[@carmelomisuraca3759]

Need to test the filter with another camera, remember the 2600 has a IR/UV cut filter. I would like to know how the l-quad compares to the l-pro. 👍

[@bikramghosh1]

Hi Peter, thanks for the unbiased review. Do you think the CLS filters have any place for widefield images or just a waste?

[@haiderbhogadia4829]

Hi Peter, I have tried the LQE and agree with your findings. Very disappointing alas!

[@PeterZelinka]

Here's the link for all the master XISF files shown in this video, along with a PDF containing all the photo details: u.pcloud.link/publink/show?code=XZ8Or50ZbQaGwh2Gd8HTHSwTs88350TpSiek I'd also recommend checking out the following review from Intergalactic Astro, he captured some great data with the L-Quad Enhance: kzbin.info/www/bejne/mGa9YqhufMuCrtUsi=PqWhdYUQV8ZhWwH1

[@rickbria8420]

Excellent video! I also find that filtered images have a red cast to the right side and a blue cast to the left. I see it in some of your examples. No one ever mentioned that in reviews and I wonder why that occurs? My tests are filtered and unfiltered agree with your results.

[@marcusholmes6768]

For targets like Horsehead, I feel it's best to shoot no filter then add in HA from the L-extreme to do an HaRGB. Longer integration times definitely helps. I try to aim for a minimum of 6 hours to start and then go back and add additional data later.

[@joeycraswell54321]

I have the new Antlia quad and got the same results. Wish I didn’t waste the money on a quadband. Better off to just shoot with no filter at all. In a 4.5 zone love the Antlia ALT-P though. Worth every penny.

[@DavidandTerriRiffle]

Hi Peter! We have had pretty good experience from a Bortle 4 with the L-Quad vs No filter. My question for you is this: What filter do you set for the L-Quad in Pixinsight SPCC? I only recently got the software and would very much like to get your feedback!

[@Masoch1st]

You probably should've also tested with a 533 as well, which doesn't have the uv/ir

[@raphaelcoelho1557]

What was total exposure time of each nebula? Amd what was each frame time exposure? Because for no filter it is possible you explode the frame if longer frames are taken

[@rockhauling.d.4816]

The question is that 2600 mc pro already have uv IR cut filter build in Can we add any filter on top of that ? I got Optolong lquad and I’m not happy It turned out as you explain here it is much noise and sho much dust show . Thanks for a great video I wish I watched this video before I bought my filter.

[@woody5109]

I’m north of your location, Okanagan area, the only clear sky’s we had so far this winter were the 5 days it was 27 below zero 😂

[@stevenrun3492]

The transmission spectrum looks very close to the Orion skyglow imaging filter. Would work if everyone was still using sodium and mercury vapor lamps, but the ongoing 1:1 replacement with broad spectrum LED lighting makes these more useless over time.

[@danwhitton7966]

This maybe an obvious question to most, but I am starting out. Would these filters be strictly for refractor scopes and astro cameras? I have a mirrorless unmodified Canon R7 and a 70-200 2.8L. This is my current starting point. I'm wondering if I could use filters like this in Bortle 1/2 skies on something like an Ra? Also, would this filter be helpful in a Monochrome workflow using ASI2600MM?

[@WRX2001]

I'm new to the hobby, If you live in an low bortle area do you require a narrow band filter to take pictures of nebulars?

[@tommykoppy6872]

When I travel to my B3 spot from my home in B9 skies. I don't use any light pollution filter unless the moon is out. But I don travel there when it's high anyway.

[@aerozg]

Peter did you test the L-Ultimate filter? I guess the results would be even worse then the L-Quad Enhance since L-Ultimate is a more aggresive filter and lets in only 2 bands of 3nm bandwidth. I was excited about both of these but apparently you need darks skies anyways, so why waste good dark skies on filters.

[@ScopesNC]

Nebul A. What is a Nebul A? B S on this video. The L Quad works very well.

[@Ben_Stewart]

Would you say this is worth upgrading from the LnEnhance?

[@commandosolo193]

you should put a link into the summary of where to buy it. Us noobs see stuff and wanna buy it.

[@DawgcityClev]

Optolong filters just didn't work for me. Sold both.

[@DLMVegas]

But still nothing for Nikon or Sony cameras and lenses.......