Glass alternative for Lee 729 Scuba Blue filter?

[Nisei]

Some of us have been experimenting with the Lee Scuba Blue 729 filter combined with KG3 or GRB3 which gives almost identical results to the Kolari IR Chrome filter.

However, it would be nice to have both filters made of glass instead of having to use the Lee 729
I was surprised to see that a seller on AliExpress is now selling a stack of 2 glass filters: QB3 & GRB3
https://www.aliexpress.com/item/1005004024273274.html
QB3 is a Chinese equivalent for Schott BG3
Has anyone here tried that combination? The last product picture even shows a camera with the IR Chrome filter on it so it's obviously intended to serve the same purpose.
The transmission charts for QB3 and Schott BG3 show they're quite a bit lower in the spectrum though, peaking below 400nm.
 

[Cadmium]

For me, the 729 filter (scuba blue) + KG3 2mm works best, better than IR Chrome.

I have found no glass filter yet that works the same as 729, but the would be nice.

 

[Nisei]

Thanks for the response Steve

Yeah, having glass filters that work the same as some Lee filters would be nice.

You've probably already tried BG3 as well? Curious about the results.

[Picareto]

The problem may be the lower % of transmission.....but looks like a good combination

[dabateman]

I am surprised they aren't stacking the QB4 with an IR cutter. 

Wasn't B410 close to IR chrome from Kolari? 

Working out a balance between that and an IR reduction filter, would probably be the key.

But than again all out cameras white balance differently and that causes problems for a general filter.

[Cadmium]

20 hours ago, Nisei said:

Thanks for the response Steve

Yeah, having glass filters that work the same as some Lee filters would be nice.

You've probably already tried BG3 as well? Curious about the results.

Yes, the BG3 + S8612 and UG5 (U-330) + S8612 go way back for UV+Blue/Green,

but those are no good for EIR simulation.

[Marc del Piro]

There is an option to reproduce IR Chrome with glass filters. I managed to find out after studying the curves and some creative process of analyzing the images. I will post it in the forum in a few days.

To be more accurate... The chinese factory I worked with is selling it already as. Please stay tuned, I will take my time to write down a post in a few days when I finish my university exams ;)

[Marc del Piro]

By the way, I tried the combination QB3 + GRB3. I'll show you the picture comparision together with other chinese filters I had been working with.

[Marc del Piro]

Here you can see the QB3 (1mm) alone and the QB3 + KG3 (1:2mm ratio). These two images are SOOC from jpg from camera. WB manually done on camera, same for both pictures: 10000ºK with strong balance towards green. Compensation of exposure is not done since I was testing the amount of light the KG3 takes away from the QB3 alone.

 

The following images are the same ones as above, but I post-processed them from the RAW. Since the original histogram is a bit underexposed on the QB3 + KG3, the contrasts look somehow different. I tried to equalize the histograms the best I could, then I edited the colours.

 

(Left/Top QB3, Right/Bottom QB3+KG3)

 

The QB3 alone cannot obtain the red folliage. The temperature had to be drown to 3000ºK, since 10000ºK gives an extreme red hue all over the image. This is foreseeable since the jpg has an extreme golden glow all over.

 

Still, I must say, the filter has a lot of possibilities when talking about creative NIR photography. I've managed to obtain some golden shots with it. Below you can see the example of the same scene brought to the golden approach.

 

(Left/Top QB3, Right/Bottom QB3+KG3)

 

I made a similar edit on LR, so you can see the slight differences each filter combination has. The QB3 alone in my case has a hotspot that is severly reduced on the combined option. So in my case, I usually travel with the combination to avoid this issue.

 

The original image without IR light is the one below. Note that there is some dried vegetation already, which creates some colour contrast on the NIR images too.

 

[Nisei]

Thanks!

Sorry, I missed these posts so I already responded to your findings in the other topic you started.

Are you buying from Nantong Foric Optical Glass company by any chance?

I usually do business with Tangsinuo Optoelectronic Tecnology company but I don't think they are selling QB19. They do have QB21 though.

 

[Marc del Piro]

Your welcome!

 

I've just answered in the other post ;) 

 

https://www.ultravioletphotography.com/content/index.php?/topic/5403-kolarivision-ir-chrome-diy-chinese-version/