IR video problem solved?

Alastair Traill · October 30th, 2018, 05:40 PM

I had trouble loading pictures into my last post of this thread so I am trying again here: -

Four IR illuminated screen shots from a Back-bone modified ‘GoPro 4 black’ using a Ninja Inferno for recording. To compensate for the light path changes resulting from the IR cut filter removal 0.0085” was removed from the lens mount.
Lens used was a 4.5 – 10 mm Infrared corrected Vari-focal.

http://www.dvinfo.net/forum/images/attach/jpg.gif
http://www.dvinfo.net/forum/images/a...attach/jpg.gif

Mick Jenner · November 1st, 2018, 10:36 AM

Gosh, very are very sharp and clear Alistair! looks like all your experimenting has paid off

Bo Skelmose · November 4th, 2018, 03:56 PM

My converted GH4’s are only for IR now. You can always put an IR filter in front of the lens but now I am using GH5’s for colour production.

Bo Skelmose · November 13th, 2018, 11:01 AM

Remember Back light when ligtning - also when using IR!

Alastair Traill · November 15th, 2018, 04:29 AM

Hi Mick and Bo,

Thanks for the interest. It was all a bit of a fiddle but I am pleased with the detail that is now possible with this relatively modest set-up.

Back-bone are now recommending an alternative approach that I am yet to explore. They are currently marketing IR Cut filters and Visible Light Cut filters for behind the lens use. They are also working on a new filter mount.

The advantage with this approach is that you use one filter or the other and if their refractive properties are the same there will be no need to change flange depth when changing from visible to IR or vice versa.

However as a lot of my clips are taken around dusk when the amount of visible light is falling steadily I worry that they will suggest that my subjects emerge later than they really do if I use a visible light cut filter. On the other hand with the amount of daylight being so variable at dusk it is hard to intercut shots taken even at slightly different times so may be getting rid of visible light could be of benefit.

October 30th, 2018, 05:40 PM	#16
Alastair Traill Major Player Join Date: Nov 2008 Location: Melbourne Australia Posts: 626	Re: IR video problem solved? I had trouble loading pictures into my last post of this thread so I am trying again here: - Four IR illuminated screen shots from a Back-bone modified ‘GoPro 4 black’ using a Ninja Inferno for recording. To compensate for the light path changes resulting from the IR cut filter removal 0.0085” was removed from the lens mount. Lens used was a 4.5 – 10 mm Infrared corrected Vari-focal. http://www.dvinfo.net/forum/images/attach/jpg.gif http://www.dvinfo.net/forum/images/a...attach/jpg.gif Attached Thumbnails

November 1st, 2018, 10:36 AM	#17
Mick Jenner Major Player Join Date: Mar 2003 Location: West Sussex England Posts: 843	Re: IR video problem solved? Gosh, very are very sharp and clear Alistair! looks like all your experimenting has paid off

November 4th, 2018, 03:56 PM	#18
Bo Skelmose Major Player Join Date: Apr 2008 Location: Denmark Posts: 495	Re: IR video problem solved? My converted GH4’s are only for IR now. You can always put an IR filter in front of the lens but now I am using GH5’s for colour production. But-Kat on Vimeo

November 13th, 2018, 11:01 AM	#19
Bo Skelmose Major Player Join Date: Apr 2008 Location: Denmark Posts: 495	Re: IR video problem solved? Remember Back light when ligtning - also when using IR!

November 15th, 2018, 04:29 AM	#20
Alastair Traill Major Player Join Date: Nov 2008 Location: Melbourne Australia Posts: 626	Re: IR video problem solved? Hi Mick and Bo, Thanks for the interest. It was all a bit of a fiddle but I am pleased with the detail that is now possible with this relatively modest set-up. Back-bone are now recommending an alternative approach that I am yet to explore. They are currently marketing IR Cut filters and Visible Light Cut filters for behind the lens use. They are also working on a new filter mount. The advantage with this approach is that you use one filter or the other and if their refractive properties are the same there will be no need to change flange depth when changing from visible to IR or vice versa. However as a lot of my clips are taken around dusk when the amount of visible light is falling steadily I worry that they will suggest that my subjects emerge later than they really do if I use a visible light cut filter. On the other hand with the amount of daylight being so variable at dusk it is hard to intercut shots taken even at slightly different times so may be getting rid of visible light could be of benefit.