Testing astrophotography filters with a HIGH RESOLUTION spectrophotometer

Thank you so much for joining Cuiv in testing and sharing filters! You two are making things better for all of us!

Woohoo!! Awesome, and well done!! Glad to see someone else joining the party. Antlia's response is very disappointing. And while Baader's customer service was good I still see some issues that are annoying, as you mentioned: - it is often not possible for normal users to see that a filter is out of spec - especially for Ha, where even a 25% transmission will look like it gives a great result - Even if a user knows that their filter seems out of whack, if they don't have a spectrometer measurement to back it up, it's likely manufacturers wouldn't accept an exchange as there is no solid proof Which means manufacturers are still able to be lax about their QC and to release filters that aren't up to spec to unsuspecting users. From my samples and yours, I'd venture that for some manufacturers, the majority of filters aren't up to spec...

Thank you for taking the time to make these tests. We can make a more educated decision when purchasing filters from these manufacturers. I’m surprised to find that some of the Antlia filters fulfill the specs, while others don’t, and to see the kind of response is nonsense. Regards, Alfredo

This is fantastic work! I was looking at Antlia filters because of their Hb / Siii dual band. From their response reported here, that's no longer the case. I'll spend my money with someone else. If they had asked about how the spectroscope was calibrated, then I could understand - perhaps your calibration was shifted and therefore the results were skewed. But that's not what they did. They started off by basically calling the customer a lier. Unacceptable.

Excellent video, Julien! Many thanks for your hard work and great explanations!!

Excellent test report, merci!

As usual, very professional video! Many congratulations

Very valuable info - thanks for taking the effort!!!!

Thanks, very interesting - I use the Optolong Ultimate and rate it superb. Astounding results.

I love that you did the hard work, and it's clear that there was lots of work needed to make this video. I definitely came to watch your video with the hopes that you would have a conclusion at the end that said something like... 'if you currently don't own any of these filters, I recommend buying these filters...'

Excellent video, thank you, thank you, thank you!!!

Julien, thanks for a deep analysis of filters, it’s great to see the specs of your testing equipment, I love Cuiv videos, yours is not a copy at all because the approach for scientific, I will love to see you check the NBZ nebula filter to see is true what they offer. Anyways thanks for great video.

Excellent! Thank you very much.

Thanks for doing this important work! 🏆

Thank you for doing all that hard work for your YouTube followers. I believe that the IDAS NDZ dual band filter is very popular especially with people that use hyperstar. I would be very interested in your review of that filter since I recently purchased one. Very grateful.

thanks for another great video!

Very interesting indeed. Thanks for the hard work. :)

Awesome test. I would love to see ZWO narrowband filter charts. A lot of people would also I’m sure. It’s a shame about your friends situation. I have great stories about Baader too. That’s a great team. Thank you for your research.

Wow, great many thanks for this work! I have to check my copy of the Baader H-alpha (CCD series 3.5nm, just as the problematic copy you tested)

Thanks for this helpful video. Would like to know how Optolong 3nn narrow band filters test.