Infrared photography—why are green leaves not appearing as white?

I'm new to IR photography. I'm trying to get the white colour out of green plants (leafs, grass etc.).

Here is my setup:

• Canon EOS 100D full spectrum - IR filter in front of sensor removed


• Samyang 24mm f/1.4


• Zomei 680 nm IR filter

I'm using Digital Photo Professional 4 to set the white balance.

Below a photo where white balance is set on the green colour of plants.

The second photo white balance is set on a white sheet of paper.

Am I missing something? Why I'm not getting the white colour like on all of the photos on the internet?

I don't have any experience in post-processing and I do not own Photoshop or Lightroom so if there is something else I should edit in the RAW files please suggest what software I should use.

Is there something else in the camera or lens that might be blocking the IR light?

Here is a link to RAW file of the above photos: RAW photo

EDIT: I did a small experiment. I used a filter that was removed from my camera which should block all IR light. I did two photos: with and without the 680 nm filter. So in theory the camera filter should be completely black when taking a photo with 680 nm filter which blocks all visible light. Here is the result:

As you can see the camera filter is not completely dark so either the 680 nm filter is passing some visible light or the camera filter is passing the infrared light (or a mix of theese two?).

Can that cause the plants being not white in the IR photos? Maybe I should try a deeper infrared filter like 850 nm or 950 nm?

Answer

Ok guys, here is an answer. It turns out that the weak point of my IR photography setup is... Zomei IR filter. I bought a high quality Hoya R72 (720 nm) infrared filter. I was shocked by the result.

• The first photo is made using the Hoya filter. White balance set on green leaves.


• The second photo is made using Zomei filter with exactly the same
  settings (exposure, ISO, aperture, white balance) as the first photo.


• The third photo is made using Zomei filter. Changed exposure time and adjusted focus slightly. Rest of the parameters unchanged.


• The fourth photo is made using Zomei filter. Exposure slightly
  changed. White balance set on a green color.

There was no post processing of any kind made to these photos except setting the white balance.

I do not know where all of these good reviews about Zomei filters come from. For me, the filter I received from Zomei is totally useless in terms of infrared photography.

I hope my investigation will help others.