Luminous Landscape Forum

Equipment & Techniques => Cameras, Lenses and Shooting gear => Topic started by: Aram Hăvărneanu on October 14, 2018, 01:09:00 pm

Title: Square (100mm) didymium filter
Post by: Aram Hăvărneanu on October 14, 2018, 01:09:00 pm
I have a circular Tiffen didymium filter. Generally it has almost no effect, but during fall it has quite a useful effect. Also it's very useful for astrophotography.

I want a square one, though, because it's more versatile. Also the Tiffen filter is uncoated. Who manufactures square didymium filters?

Breakthrough has one (https://breakthrough.photography/products/night-sky-filter?variant=11505393172522), but it's on backorder.

Tiffen used to have one (https://www.bhphotovideo.com/c/product/57022-REG/Tiffen_44EF1_4x4_Enhancing_Glass.html), but no longer.

Anyone else?
Title: Re: Square (100mm) didymium filter
Post by: BRH on October 14, 2018, 01:47:23 pm
Try the following;
https://www.lonelyspeck.com/purenight/

https://nisifilters.com.au/product/nisi-100x100mm-natural-night-filter/


https://www.amazon.com/NiSi-100X100mm-Natural-Night-Astrophotography/dp/B06XK8H3L9

https://www.alibaba.com/product-detail/Premium-Optical-Quality-Didymium-Glass-PNB586_1867203987.html?spm=a2700.7724857.normalList.33.4f6f706bHrF5by

Bryan
Title: Re: Square (100mm) didymium filter
Post by: Alan Smallbone on October 15, 2018, 09:49:20 am
I have the NISI and it works great.

Alan
Title: Re: Square (100mm) didymium filter
Post by: Aram Hăvărneanu on October 15, 2018, 09:58:32 am
Is the NiSi one truly Didymium glass? I've heard conflicting reports.
Title: Re: Square (100mm) didymium filter
Post by: Alan Smallbone on October 18, 2018, 09:21:08 am
I have another from a random Chinese manufacturer that seems to behave much like the Nisi. I got it because the lens I wanted to use it on was the Laowa 9mm for FujiX and the square filters system caused vignettes. In taking images at night I see very much the same effect from both filters. I did not test the spectrum of both but did test the Nisi, and here is the result:
https://flic.kr/p/26EKVpN

There is a big notch in the spectrum around the sodium vapor light spectrum. So it is blocking mostly yellows.

Alan
Title: Re: Square (100mm) didymium filter
Post by: Alan Smallbone on October 18, 2018, 09:23:16 am
As a side note in general I avoid Tiffen filters, and this is my own bias. I have had too many experiences with poor filter quality or color casts that I just avoid them in general.

Alan
Title: Re: Square (100mm) didymium filter
Post by: Aram Hăvărneanu on October 18, 2018, 09:37:18 am
Fantastic, thank you!