IR Filters

[Alex Vasile]

So I have finally gotten a chance to do some tests out the IR filters purchased. The filters come as a set of 4: 720nm, 760nm, 850nm, and 950nm. I originally bought this pack because it was cheap and wanted to test things out before buying the more expensive ones, though as you'll see later I may not need to replace most of them!

I got the set in 67mm for $77 USD all in; Kolari sells a single filter of that size for $77 USD plus shipping. Of note is that the Neewer filters are available in a substantially smaller number of sizes, 67mm happen to work out for me since that's what I'm standardizing on anyway.

I'm comparing them against Kolari's Pro and standard filters. Transmittance data for Kolari filters is taken from their site, Neewer data I measured myself using a UV-VIS. The machine only went up to 1050nm, so that's all I got. The vertical lines represent the nominal labeled value for each filter. They are all color coded to match the curves. The 760nm vs 780nm is not a typo, that's just the closest comparable filter.

My takeaways

• The maximum transmittance once the curve flattens out in the IR range of the Neewer and the non-pro Kolari filters are basically the same from my point of view.
• The 720nm Kolari looks to have better <720nm rejection. I don't know how noticeable the difference is.
• The 760nm vs 780nm appear to have similar shapes to their curves. That being said, I don't think they're interchangeable as I imagine the 20nm differences is fairly large in that range.
• The 850nm filters are basically the same.
• The 950nm appears to be substantially worse in terms of cutoff slope and maximum transmittance. This is actually what I was expecting all of them to look like, so I was happily surprised. I don't have other data to compare this against to know if other filters do much better.

 

[AlanLichty]

Certainly a nice price for the set compared to the Kolari. Do you have any of the Kolari filters in a similar wavelength to the Neewer ones in the set? I would be curious to see/hear about some real world comparisons on how well they work. I bought Kolari's 720nm filter and use it with my converted Canon 5D MkII and it works well but I have no point of comparison. Kolari doesn't give them away so I never got around to buying a whole set of them.

 

[JimFox]

That's a super interesting test Alex. The Pro version does look substantially better, but the normal version compares pretty equally to the inexpensive Neewer brand.

I use a Nikon D7100 I had converted to 590nm that I really like. I had settled on the 590nm being my favorite personal preference, but each one does add a different element to the look of an image. I have seen some of the guys stacking say a 720nm on top of a 590nm. I haven't tried that, but I might be curious to use an 850nm on top of my 590nm.

 

[Alex Vasile]

Certainly a nice price for the set compared to the Kolari. Do you have any of the Kolari filters in a similar wavelength to the Neewer ones in the set? I would be curious to see/hear about some real world comparisons on how well they work. I bought Kolari's 720nm filter and use it with my converted Canon 5D MkII and it works well but I have no point of comparison. Kolari doesn't give them away so I never got around to buying a whole set of them.

I do not. I recently ordered some other filters from them, but have no comparison. What I will say about the Neewer ones is that they do feel cheaper than say the B+W CPL filters I have, but not enough to make me worried about their durability. The other thing is that both the glass and the filter as a whole is quite thing and have no "knurling"/grip on the metal, so they can be difficult to take off.

That's a super interesting test Alex. The Pro version does look substantially better, but the normal version compares pretty equally to the inexpensive Neewer brand.

I use a Nikon D7100 I had converted to 590nm that I really like. I had settled on the 590nm being my favorite personal preference, but each one does add a different element to the look of an image. I have seen some of the guys stacking say a 720nm on top of a 590nm. I haven't tried that, but I might be curious to use an 850nm on top of my 590nm.

Yeah, the pro ones look objectively better in every way (even physically, they have grips built into the outside which looks very helpful). Their coatings probably help with smudges and dust and the like. Whether that's worth a 36% premium over their own non-pro version is a question of budget.

The stacking sounds very interesting. I will definitely try that!

 

[Alex Vasile]

Update on this after a several months of usage:

1. I find I don't use the 950nm that often. Mostly due to the longer exposures/higher ISO needed for it. I wish the filter's transmittance was higher.
2. The filters build up a lot of static electricity on their surface. Cleaning dust off of them is very difficult.

 

[Jameel Hyder]

I splurged on the Kolari set (the non pro ones) as I now have a full spectrum converted camera (Canon SL3) and I also bought the 67mm version since I have a 18-135mm lens on the body and that is pretty much all I have used. Again no frame of reference with other brands to compare.

 

[Alex Vasile]

I splurged on the Kolari set (the non pro ones) as I now have a full spectrum converted camera (Canon SL3) and I also bought the 67mm version since I have a 18-135mm lens on the body and that is pretty much all I have used. Again no frame of reference with other brands to compare.

Do your non-pro version have a static build-up problem?

 

[Jameel Hyder]

Do your non-pro version have a static build-up problem?

A little bit - nothing that worries me however.