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Formatt Pro Stop IRND Filters?

Julio Quintana

Julio Quintana

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Hey guys. Have any of you tested the Formatt Pro Stop IRND filters on the Epic? A few people on the forum seem to feel that a hot mirror is more affective, but I tend to shoot towards the sun a lot and the hot mirror reflects back onto my subject too much.

Are the Pro Stops like that also or do they reflect light in a way more similar to a normal ND filter?

Julio
 
I own the Format IRNDs, I couldnt find any info about the Pro stop series or how they were different from their IRND line. Starting at ND9 I would make that an IRND (I have the scarlet). Wouldnt a hot mirror or a IRND filter have the same front surface...? my IRNDs have the mirror on the front and ND inside and behind that.
 
The Formatt IRND Pro Stop filters are not hot mirrors. They are reflect about as much as any standard filter. I love my set and find them to be the best non Hot Mirror solution. I do find them to have a bit of a blue-ish tint as you go to the higher densities but that is much better than the green-ish tints I get from other IRND solutions.
 
The ProStops are not a Hot Mirror, that is why they are a different product to Formatt's Hot Mirror solution. They are new formulation of their IRND solution.
 
Michael Notar said:
How are they different than the current IRNDs?

Yes but they contain a hot mirror don't they? I assume IR blocking and hit mirror filter are the same thing... The same layer of material if used in a combo filter.
Click to expand...

They are not the same thing. Hot mirrors generally refer to depositing a thin film of metal or other compound on the glass such that the layer reflects certain wavelengths in the InfraRed range. As the name implies they are somewhat reflective in nature, and can reflect some visible light too. This usually means using them as the frontmost filter furthest away from the lens. IRNDs tackle the problem by using dyes or materials which absorb InfraRed light of certain frequencies. They tend not to be any more reflective than plain NDs, so can potentially be stacked. Both approaches have pros and cons, but can both work well.

Their formulations are somewhat complimentary to the InfraRed filtering already in the particular camera, which is why some solutions work better with some camera models than others.
 
Both types of IR filters are made the same way -- thin metallic film formulation. The difference is that one mostly reflects (hot mirror), while the other mostly absorbs and diffuses. There are pros/ cons to each approach. I haven't tried the Formatt Pro Stop IR filters yet. They seem like a handy thing to have as they may be more compatible with placing a pola or perhaps other effect filters in front of them.
 
Most of your very dense (over 8 stops or so) filters typically are resin. I think it's because they have to impregnate the resin with the light blocking elements in addition to a surface film. The better filters, glass or resin, will sandwich the film within the filter rather than doing a straight surface coating.
 
Based on the article below, I am under the impression that Formatt Prostop range has been redesigned in 2013 and that the filters currently on sale are different from earlier Prostop versions. I am not sure if there is any visible difference or not, but I did order a set of 0.3-1.8 glass versions of the filter with the recent group buy discount.

http://kspphoto.wordpress.com/2013/01/30/new-formatt-hitech-prostop-irnd-filters/
 
trying to decide between a set of Formatt HMIRND or Pro Stop IRND...

Any recommendations ? What would you prefer ?

As I understand it the hot mirror completely block IR but potentially reflect light onto your subject, which might not be desired...

Any other considerations ?

Is the Pro Stop a newer formula and are the HMIRND an "older" formula ?


Thanks !

- M
 
The ProStop filters are the newer formulation.

ProStop filters are attenuated NDs. This means that they are extended range neutral density filters, extending into the Far Red and infrared part of the spectrum. They do with with color dyes that are carefully balanced throughout the range. Think of them as "really neutral" neutral density filters.

HMIRND filters have Hot Mirrors. This is a filter with a dichroic layer that specifically reflects light at specific color frequencies. They can exhibit other issues though, such as wide angle lenses which look through the filter at an angle towards the edges may see an odd color cast in the far edges of the images.

I conducted a fairly comprehensive test comparison of the various IR solutions for several cameras including Red in the AbelCine EXPO: Filters For Digital Cinema. Here's a link:

http://training.abelcine.com/abelcine-expo-filters-for-digital-cinema/
 
Mitch Gross said:
The ProStop filters are the newer formulation.

ProStop filters are attenuated NDs. This means that they are extended range neutral density filters, extending into the Far Red and infrared part of the spectrum. They do with with color dyes that are carefully balanced throughout the range. Think of them as "really neutral" neutral density filters.

HMIRND filters have Hot Mirrors. This is a filter with a dichroic layer that specifically reflects light at specific color frequencies. They can exhibit other issues though, such as wide angle lenses which look through the filter at an angle towards the edges may see an odd color cast in the far edges of the images.

I conducted a fairly comprehensive test comparison of the various IR solutions for several cameras including Red in the AbelCine EXPO: Filters For Digital Cinema. Here's a link:

http://training.abelcine.com/abelcine-expo-filters-for-digital-cinema/
Click to expand...

Mitch, thank you for your reply.

The video you posted is roughly 3 hours, so unfortunately cannot watch the entire presentation right now, is there a specific segment for the Red camera(s) and if so at what time does it start ?

I did watch your other video posted on page 1 of this thread from 12/10/2012.

It appears that in one test towards the end of the video, a Tiffen HMIRND filter was more effective on the Epic than the standard Formatt IRND's...

Since I intend on using Formatt filters on the MX sensor, I was (now) considering HMIRND as an alternative option to Pro Stop IRND...

Which solution would you recommend for the Red MX sensor ?


Thanks !

- Mike
 
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