Chroma filter advice

I use chroma filters, purchased in early 2022. I put these filters into a filter wheel, and the edges are covered, so if i detach the camera i cant see the edges. I didnt notice any degradation so far. What i noticed though, was the central transmission wavelength (CWL) has been off in one of my filters. So it didnt match the requirements i had given with respect to f-ratio. I have access to a laboratory with some fancy spectrometers… So i returned the filter and got replacement.
Exactly at that time, Antlia entered the marked, and they do cherry pick their filters, to match the CWL to the customer’s need. I think every brand should have adopted to this practise since, because it makes a lot of sense. I had some discussions about this with Chroma, but i dont know for sure if they do it today.

Before i had these filters, i used other filters in filter drawers. And since i was a bit short of these drawers, a lot of handling was involved. Especially when handling in the dark and in a hurry, this can quickly result in some fingerprints. And if these fingerprints aren’t removed instantly and properly, thery might become permanent.
So, my recommendation would be, to not only look for degradation, especially at the edges, but also for finger prints, dots (from droplets), scratches or smearing from improper cleaning. Knowing how the filters have been used before, can help.

HR_Maurer · May 29, 2026, 05:56 PM

I use chroma filters, purchased in early 2022. I put these filters into a filter wheel, and the edges are covered, so if i detach the camera i cant see the edges. I didnt notice any degradation so far. What i noticed though, was the central transmission wavelength (CWL) has been off in one of my filters. So it didnt match the requirements i had given with respect to f-ratio. I have access to a laboratory with some fancy spectrometers… So i returned the filter and got replacement.
Exactly at that time, Antlia entered the marked, and they do cherry pick their filters, to match the CWL to the customer’s need. I think every brand should have adopted to this practise since, because it makes a lot of sense. I had some discussions about this with Chroma, but i dont know for sure if they do it today.

Before i had these filters, i used other filters in filter drawers. And since i was a bit short of these drawers, a lot of handling was involved. Especially when handling in the dark and in a hurry, this can quickly result in some fingerprints. And if these fingerprints aren’t removed instantly and properly, thery might become permanent.
So, my recommendation would be, to not only look for degradation, especially at the edges, but also for finger prints, dots (from droplets), scratches or smearing from improper cleaning. Knowing how the filters have been used before, can help.

i have heard some bad things about antlias halo performance, and had a really bad experience. One of their filters i recieved was defective, had some halo issues.. antlia responded in a week and said it is within factory tolerances.. thank god the retailer offered me a replacement

HR_Maurer · May 29, 2026, 06:52 PM

Jan Hlavačka · May 29, 2026, 06:35 PM

A wrong CWL is pretty insane, i have never heard about that yet, and definitely wouldnt expect it from chroma

it wasnt exactly wrong. The line emission was within transmission maximum, when measured at 90° incidence angle. That’s the transmission spectrum manufacturers typically show. However, it was closer to the blue end of it. At a smaller incidence angle, the CWL shifts towards the blues, so the filter would effectively reduced my f-ratio by some stops. Indeed, from a brand like Chroma i would expect this to be spot-on.

What do you think about the condition of the filters i sent a few messages above?

I recently got Chromas and asked about the slightly blue shifted transmission of my Oiii. Note, still within spec for primary but peak shifted toward the secondary. I was told it should be fine for my setup. I havent had a chance to test them extensively enough to verify it though. I also wonder if others have had similar experiences, and if it has affected their results?

Jan Hlavačka · May 29, 2026, 04:32 PM

Hi everyone,

I’m looking for some advice from people with experience using Chroma narrowband filters long-term.

I found a set of used Chroma 5nm filters (Ha, OIII, SII) from 2021 at a reputable astronomy shop. They are listed in excellent condition, and Chroma confirmed they are genuine 2021 production. Price is around €412 per filter, compared to about €687 new.

I know Chroma uses hard sputtered coatings and even offers a lifetime warranty on sputtered catalog filters, which sounds reassuring. However, I also came across a few reports (for example on CloudyNights) of some filters showing brown discoloration on the edges / possible coating issues after a relatively short time, which made me hesitate. I am also worried about the coating technology being outdated, and i want this to be a one time purchase so if the new chroma filters offer an performance improvement i am willing to pay up.

So I wanted to ask people with real long-term experience:

• Have any of you used 2020–2021 Chroma narrowband filters (Ha/OIII/SII)?

• Have you seen any coating degradation, edge browning, or performance changes over time?

• Do you think buying a 2021 used set is a reasonable move, or would you personally spend more and buy new for peace of mind?

• If you bought used Chroma filters, what specific things would you inspect before purchasing?

For context, these would be used on an f/4 Newtonian with an ASI2600MM

I’d really appreciate honest feedback from people who have actually owned and used Chroma filters for several years.

Thanks!

I have just sold a Chroma SHO set (Ha 8nm, Sii 5nm, Oiii 5nm) 50mm round unmounted for about the same price. I was second owner (got them in 2023), and the first owner had them since 2020. They looked absolutely perfect when I sold them. No discoloration or coating degredation at all. I have used them well over a thousand hours in remote locations. Just ask the seller to send you some nice close up pictures of both sides of each filter, and maybe a set of recent flats taken with each filter and recent stacked images.

Chroma is great, but even their filters can have lemons. I had two Ha filters that had bad halo problems that got replaced by Chroma no questions asked. But since you are a second hand buyer, I don’t think Chroma would do that. Maybe I am wrong. If they do that would be even more incredible customer service.

Ashraf AbuSara · May 30, 2026 at 01:22 PM

Jan Hlavačka · May 29, 2026, 04:32 PM

Hi everyone,

I’m looking for some advice from people with experience using Chroma narrowband filters long-term.

I found a set of used Chroma 5nm filters (Ha, OIII, SII) from 2021 at a reputable astronomy shop. They are listed in excellent condition, and Chroma confirmed they are genuine 2021 production. Price is around €412 per filter, compared to about €687 new.

I know Chroma uses hard sputtered coatings and even offers a lifetime warranty on sputtered catalog filters, which sounds reassuring. However, I also came across a few reports (for example on CloudyNights) of some filters showing brown discoloration on the edges / possible coating issues after a relatively short time, which made me hesitate. I am also worried about the coating technology being outdated, and i want this to be a one time purchase so if the new chroma filters offer an performance improvement i am willing to pay up.

So I wanted to ask people with real long-term experience:

• Have any of you used 2020–2021 Chroma narrowband filters (Ha/OIII/SII)?

• Have you seen any coating degradation, edge browning, or performance changes over time?

• Do you think buying a 2021 used set is a reasonable move, or would you personally spend more and buy new for peace of mind?

• If you bought used Chroma filters, what specific things would you inspect before purchasing?

For context, these would be used on an f/4 Newtonian with an ASI2600MM

I’d really appreciate honest feedback from people who have actually owned and used Chroma filters for several years.

Thanks!

I have just sold a Chroma SHO set (Ha 8nm, Sii 5nm, Oiii 5nm) 50mm round unmounted for about the same price. I was second owner (got them in 2023), and the first owner had them since 2020. They looked absolutely perfect when I sold them. No discoloration or coating degredation at all. I have used them well over a thousand hours in remote locations. Just ask the seller to send you some nice close up pictures of both sides of each filter, and maybe a set of recent flats taken with each filter and recent stacked images.

Chroma is great, but even their filters can have lemons. I had two Ha filters that had bad halo problems that got replaced by Chroma no questions asked. But since you are a second hand buyer, I don’t think Chroma would do that. Maybe I am wrong. If they do that would be even more incredible customer service.

Thank you for this feedback! I really appriciate it! I believe Chroma would do that, im pretty sure they have a lifetime gurantee for defects, but i have a different question. The seller has a 15 day money back return policy, so from the day i recieve the filters, i have 15 days to try them and if im unsatisfied, i can return them for the full price! The question is, what tests should i perform to assure myself they will serve me well? Thanks,

Jan

Hi Jan,

I've been using a Chroma OIII 3nm filter for many years, and it's by far the best filter I've ever used, with no change in quality over time. I have filters from other brands, some very good, but if I could, I'd buy them all from Chroma. On another note, I have to say that the company's after-sales service is excellent; they always help you with any questions or problems you have with the filter.

CS

Christian

Jan Hlavačka I am glad you confirmed what i was thinking.. Now the main concern is that if i should get the brand new ones for the higher price, or get the used ones..

Buy the used ones, there’s no difference in the quality and still under full warranty.

I don’t think you’d need to test them, but the seller would need to be honest in stating that the filters are in excellent condition and have no cosmetic issues. The OP did state that the filters are from a reputable astronomy shop and in excellent condition.