The Infrared Thread

[Scottelly]

I was researching IR photography and filters, and I came across some interesting stuff, which I thought might have a place here in one of the threads about using Sigma cameras for shooting IR photos, but there are so many threads here! I decided to make the one thread to rule them all.



In this thread I will create a list of previous threads (some will be IR images posted in weekly image threads, which sometimes include information about how the image was created or information about ways to create IR images or full-spectrum images), and I will include a list of interesting links in one reply too. I hope to see some more information from others posted here, though there has already been SO much posted in this forum about IR photography.

Please take a look at my first reply to this thread if you want to see the list of previous threads about IR or even full-spectrum photography using Sigma cameras. I'll try to make it pretty extensive, and I am planning to include the word Aerochrome next to the links to threads which mention is or are about achieving the look of Aerochrome film.

I'd be interested to see IR photos you shot with your Sigma camera here in this thread if you have some to post, and any explanation you might be able to offer about how you produced the image(s) would be GREAT!

Thanks in advance for any of your input.

 

[Scottelly]

https://www.dpreview.com/forums/post/68345938

https://www.dpreview.com/forums/post/68295920

https://www.dpreview.com/forums/post/68291640

https://www.dpreview.com/forums/post/68214796 - Aerochrome
https://www.dpreview.com/forums/post/68127006 - Aerochrome

https://www.dpreview.com/forums/post/67854925

https://www.dpreview.com/forums/post/68193612

https://www.dpreview.com/forums/post/68091355

https://www.dpreview.com/forums/post/67989091

 

[sattva]

https://www.dpreview.com/forums/post/68345938
https://www.dpreview.com/forums/post/68295920
https://www.dpreview.com/forums/post/68291640
https://www.dpreview.com/forums/post/68214796 - Aerochrome
https://www.dpreview.com/forums/post/68127006 - Aerochrome
https://www.dpreview.com/forums/post/67854925
https://www.dpreview.com/forums/post/68193612
https://www.dpreview.com/forums/post/68091355
https://www.dpreview.com/forums/post/67989091

Thank you very much Scott! Very useful resource.

Interestingly, i was reading about IR photo making just this week...and now your post pops up!

Best regards,

Sattva

 

[xpatUSA2]

https://www.dpreview.com/forums/post/68345938
https://www.dpreview.com/forums/post/68295920
https://www.dpreview.com/forums/post/68291640
https://www.dpreview.com/forums/post/68214796 - Aerochrome
https://www.dpreview.com/forums/post/68127006 - Aerochrome
https://www.dpreview.com/forums/post/67854925
https://www.dpreview.com/forums/post/68193612
https://www.dpreview.com/forums/post/68091355
https://www.dpreview.com/forums/post/67989091

Let's get technical ... simulating Kodak Ektachrome EIR film:

http://kronometric.org/phot/ir/SD1M%20Kodak%20IR%20film%20simulation.pdf

Lots of filter data and examples!

 

[Scottelly]

Cool. Thanks for adding that link Ted.



I actually meant to put a lot more links in that page of links to threads, but I got distracted, and I didn't want to lose what I had already started, so I decided to post what I had gathered together, and let this thread get going. I need to spend an hour or two, searching back through the various threads in this forum to find a few more threads to link to here.

 

[danski0224]

SD1M Full Spectrum (FS)


SD1M FS + 580 nm filter


SD1M FS + 720 nm filter


SD1M FS + Kolari Hot Mirror filter


SD1M FS + Kolari + Monochrome conversion in SPP

All have had levels adjusted and cropped. White balance and tint on color image (and yes, color is not "correct", but I find it interesting).

Camera position did not change.

Getting exposure to remain consistent is very difficult, and judging what you have from the screen is nearly impossible, other than if it is "black" or "bright white", it's no good. They usually have to look significantly underexposed on the screen to be "good".

--
Moments in Time, a work in progress.... https://www.flickr.com/gp/142423236@N08/965cs3

 

[xpatUSA2]

danski0224 wrote:All have had levels adjusted and cropped. White balance and tint on color image (and yes, color is not "correct", but I find it interesting).

Super shots, Dan !!

Getting exposure to remain consistent is very difficult, and judging what you have from the screen is nearly impossible, other than if it is "black" or "bright white", it's no good. They usually have to look significantly underexposed on the screen to be "good".

In the end I sold my Sigma SD15 and got my Lumix DMC-G1 converted - so much easier with the live-view EVF & LCD and with the WB set to 3500K ....

 

[danski0224]

Super shots, Dan !!

In the end I sold my Sigma SD15 and got my Lumix DMC-G1 converted - so much easier with the live-view EVF & LCD and with the WB set to 3500K ....

Thanks, Ted.

I have been considering having a fp-l converted. I don't know if I want to just do a full spectrum conversion... or go further and have it de-Bayered. Last I looked, some of the autofocus is lost with the de-Bayer process, so that is a negative.

At least with a full spectrum conversion, it should go back to "normal" with a Kolari hot mirror, unlike the SD1M.

Unfortunately, the tariffs have brought any discretionary purchases from Japan to a halt, so any conversion stuff isn't happening anytime soon.

Looks like a Kolari full spectrum conversion with the better clear optical glass replacement is pushing $500.00.

--
Moments in Time, a work in progress.... https://www.flickr.com/gp/142423236@N08/965cs3

 

[xpatUSA2]

Taken with their SD10; found it in Wiki ...

 

[Scottelly]

Cool photo! Thanks Ted.

 

[Scottelly]

Nice! I prefer the one made with the 720 nm filter. Thanks for posting those.

 

[danski0224]

Nice! I prefer the one made with the 720 nm filter. Thanks for posting those.

That filter can make nice images, but it is more finicky on the SD1M than the basic red 590 nm (just checked Kolari, and their red appearing filter is 590 nm, which must be what I have). Pretty much have to be f/8 all of the time because focus is off.

I have a 780 nm filter, but have found the results to be much less than ideal, probably due to how the Foveon sensor works.

The Quattro sensor is not good (IMHO) for anything other than either full spectrum (FS) or FS + the 590 nm filter. Probably because of the reduced resolution at the lower layers of the sensor. I really was hoping for better, because of the live view, but nope.

And of course, what Foveon/Quattro does seems to be way different from a Bayer sensor, based on images seen on conversion sites... or it is user error (certainly possible).

I do not have a FS Bayer sensor camera.

I actually like the monochrome images that come from the Kolari hot mirror, they are different from a Merrill image with the factory dust protector. But when the 720 nm filter image comes out really nice, it is hard to beat. The Kolari one is much easier to get.

--
Moments in Time, a work in progress.... https://www.flickr.com/gp/142423236@N08/965cs3

 

[xpatUSA2]

Nice! I prefer the one made with the 720 nm filter. Thanks for posting those.

That filter can make nice images, but it is more finicky on the SD1M than the basic red 590 nm (just checked Kolari, and their red appearing filter is 590 nm, which must be what I have). Pretty much have to be f/8 all of the time because focus is off.

For some years, I had the Marumi 700 nm which was pretty good - often "better" that the almost mandatory Hoya 720 nm. I could usually just make scenery for composition through the viewfinder. I may still have it somewhere, 77 mm thread.

 

[danski0224]

For some years, I had the Marumi 700 nm which was pretty good - often "better" that the almost mandatory Hoya 720 nm. I could usually just make scenery for composition through the viewfinder. I may still have it somewhere, 77 mm thread.

Interesting.

There doesn't seem to be much available at 700 nm for camera filters, at least with a quick search. Singh-Ray has one.

 

[SigmaTog]

Nice work Dan
The fp & fp-L are easy to convert.
The Kolari Pro 2 hot mirror is a perfect match to the converted fp for visible light photography.
The Foveon sensor cameras give the best colour near IR images.
The Bayer sensor cameras give the best colour UVA images.

 

[SigmaTog]

Gary Radford & myself have done a lot of Foveon IR & full spectrum photography in the past.

 

[danski0224]

Nice work Dan
The fp & fp-L are easy to convert.
The Kolari Pro 2 hot mirror is a perfect match to the converted fp for visible light photography.
The Foveon sensor cameras give the best colour near IR images.
The Bayer sensor cameras give the best colour UVA images.

Thanks.

What is meant by "colour near IR images" and "UVA images"?

 

[SigmaTog]

Nice work Dan
The fp & fp-L are easy to convert.
The Kolari Pro 2 hot mirror is a perfect match to the converted fp for visible light photography.
The Foveon sensor cameras give the best colour near IR images.
The Bayer sensor cameras give the best colour UVA images.

Thanks.

What is meant by "colour near IR images" and "UVA images"?

The quantum efficiency graphs for Foveon & Bayer are quite different.
Foveon sensors have more colour information in near IR.
Bayer sensors have more colour information in UVA, even if it is false colours.

This is an example of the Foveon sensor, it has plenty of colour information in the near IR, but only the blue channel below 400nm.

https://www.mdpi.com/jimaging/jimag...deploy/html/images/jimaging-02-00014-g002.png

Example of a Bayer sensor with extended response.

 

[danski0224]

Graphs are cool, but what does it mean for taking a picture?

 

[xpatUSA2]

Graphs are cool, but what does it mean for taking a picture?

You could think of sensor response graphs as being equivalent to filter transmission curves. If you put a filter on the lens, you get a different picture than without the filter.

Here's an early SD9 sensor response with and without an IR blocking filter:

If the scene is pure green 555 nm, it can be seen that the channel responses at that wavelength are quite different and so therefore will be the pictures.

HTH