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Author Topic: IR ND for Sony A7RIII?  (Read 241 times)

smthopr

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IR ND for Sony A7RIII?
« on: January 25, 2019, 11:07:43 AM »

I have some work coming up where I will be using a Sony A7RIII to shoot a little movie.  And, at 800 ISO, that will require using some heavy ND filters.

Does anyone have a suggestion about what would be a good choice of ND filters to use with this camera?  I will need ND .9, 1.5, and 2.1 filters.  I am concerned about IR contamination and assume I will need IRND filters when working with ND filters darker than .9.

I am looking for filters that will have a minimum of color shift.  And are there filters that are best matched, IR blocking wise, to this camera and sensor?

I believe our lenses take a 72mm screw mount.

Thanks!
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smthopr

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Re: IR ND for Sony A7RIII?
« Reply #1 on: January 26, 2019, 02:32:02 PM »

No one is using heavy ND filters with these Sony cameras?

It doesn't matter if your shooting stills and not movies, so if you're shooting stills with heavy ND filters please feel free to offer suggestions :)
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E.J. Peiker

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Re: IR ND for Sony A7RIII?
« Reply #2 on: January 26, 2019, 03:03:45 PM »

This test has a spectral response curve that extends into very near infra-red for some of the most popular filters.  Basically B+W, Lee, and Tiffen do not cut the IR spectrum well at all:
https://www.onlandscape.co.uk/2017/07/nd-filters/

I have also done quite a bit of testing and the most neutral I have found is the Breakthrough X4. In my test and in my experience, Singh-Ray also does not cut the IR part of the spectrum well.  These were done on the a7R II which uses the same sensor as the a7R III - it starts on Page 6:
http://www.ejphoto.com/Quack%20PDF/Quack%20Winter%202017.pdf
« Last Edit: January 26, 2019, 03:06:46 PM by E.J. Peiker »
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smthopr

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Re: IR ND for Sony A7RIII?
« Reply #3 on: January 27, 2019, 02:37:39 PM »

This test has a spectral response curve that extends into very near infra-red for some of the most popular filters.  Basically B+W, Lee, and Tiffen do not cut the IR spectrum well at all:
https://www.onlandscape.co.uk/2017/07/nd-filters/

I have also done quite a bit of testing and the most neutral I have found is the Breakthrough X4. In my test and in my experience, Singh-Ray also does not cut the IR part of the spectrum well.  These were done on the a7R II which uses the same sensor as the a7R III - it starts on Page 6:
http://www.ejphoto.com/Quack%20PDF/Quack%20Winter%202017.pdf

thanks for the links.  Very helpful!
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Chris L

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Re: IR ND for Sony A7RIII?
« Reply #4 on: January 29, 2019, 06:11:59 PM »

No one is using heavy ND filters with these Sony cameras?

It doesn't matter if your shooting stills and not movies, so if you're shooting stills with heavy ND filters please feel free to offer suggestions :)

I shoot my Sony a7r2 with the Tiffen water white IRND 77mm filters. It has IR cut built in. I haven't don't it much as I usually use these with the BM Ursa Mini but when I do on the Sony it looks good. No color shift or remaining IR pollution. This is with Canon L lenses and Leica R lenses. Hope that helps.
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smthopr

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Re: IR ND for Sony A7RIII?
« Reply #5 on: January 30, 2019, 11:44:45 AM »

I shoot my Sony a7r2 with the Tiffen water white IRND 77mm filters. It has IR cut built in. I haven't don't it much as I usually use these with the BM Ursa Mini but when I do on the Sony it looks good. No color shift or remaining IR pollution. This is with Canon L lenses and Leica R lenses. Hope that helps.
I have used Tiffen IRND filters in the past and the color shifts were quite difficult to correct.  Unless these are a brand new product, I'm staying away from Tiffen IR filters.  For landscapes, it might not be a big deal, but for color correcting images of people that need to match shot to shot and filter to filter, they were problematic.

But thanks for chiming in, I appreciate it!
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