|	 Agfa 	Ilford	Kodak	Kodak 	Konica	 Maco	|
     |	APX200S	SFX200	 EIR	 HIE	 750IR	IR820c	|
--------------------------------------------------------------
NONE |	200	 200	 250	 400	  32	200-400	| NONE
     |							|
 #8  |							| #8
     |							|
#12  | 			 250				| #12
     |							|
#16  |							| #16
     |							|
#21  |							| #21
     |							| 
#25  | 				  50	   8	 100	| #25
     |							|
#29  |							| #29
     |							|
#70  |							| #70
     |							|
#89B |						  50	| #89B
     |							|
#88A |	  -	  -	  -		   4	  -	| #88A
     |							|
#87  |	  -	  -	  -		 1-2	  -	| #87
     |							|
#87C |	  -	  -	  -	  12	  -	  -	| #87C
     |							|
#87B |	  -	  -	  -	  	  -	  -	| #87B
     |							|
#87A |	  -	  -	  -		  -	  -	| #87A
--------------------------------------------------------------
     |							|
     

'-' means not recommended, beyond the practical range of the film, not adding to pictorial 
    effects, only making the film slower. In case of EIR, it will create only a monochrome
    red image.


IMPORTANT NOTE: THE ABOVE IS EFFECTIVE ASA, OR EXPOSURE INDEX....ONLY CORRECT WHEN 
		YOU TAKE AN EXPOSURE READING _W_I_T_H_O_U_T_ FILTER IN FRONT OF THE 
		CAMERA/LENS/LIGHT-METER ! ! ! !

                IF YOU TAKE A LIGHT-METER READING _T_R_O_U_G_H_ YOUR FILTER, YOU HAVE 
		TO CALIBRATE YOUR CAMERA OR EXTERNAL LIGHT METER, SO THAT THE RESULT 
		WILL BE THE SAME ! ! ! !



 The Sunny Sixteen Rule 

A lovely simple exposure start is the "Sunny Sixteen Rule":
Requirement: clear sunny day (not at sunrise/sunset cq dawn/dusk!)
Setting:

 aperture f16 
  &
 shutterspeed 1/ASA seconds

Example: 
 Kodak HIE & #87C infrared => 12 ASA => f16 @ 1/12s => f8 @ 1/50s (or 1/60s) etc.

 The typical bracket range on my Horizon 202 therefore becomes f5.6-11 @ 1/60s .

 For Kodak HIE & #25 red => 50 ASA => f16 @ 1/50s => f8 @ 1/200s, or a bracket 
 of f5.6-11 @ 1/250s




Date sent:        Fri, 16 Nov 2001 23:27:30 -0800
From:             HypoBob 
Subject:          Different HIE exposure at different distances???
To:               infrared@a1.nl
Organization:     PacBell  "We make AOL look great."
Send reply to:    infrared@a1.nl

The Kodak data sheet states that HIE should be exposed 1/125 @ f/11 for distant
scenes and at 1/30 @ f/11 for nearby scenes.  A difference of  two f/stops.

Could someone please explain the logic behind this recommendation.

Let's take this idea to a logical extreme.  If I stand close to a large tree on
a sunny day and photograph it with a 17mm lens, then I should use 1/30 @ f/11. 
If I move far away and frame the tree identically with a 1600 mm lens then I
should use 2 stops less exposure???

Bob





From:             "Willem-Jan Markerink" 
To:               infrared@a1.nl
Date sent:        Sat, 17 Nov 2001 18:18:57 +0100
Subject:          Re: Different HIE exposure at different distances???
Send reply to:    infrared@a1.nl

On 16 Nov 01 at 23:27, HypoBob wrote:

> The Kodak data sheet states that HIE should be exposed 1/125 @ f/11 for
> distant scenes and at 1/30 @ f/11 for nearby scenes.  A difference of  two
> f/stops.
> 
> Could someone please explain the logic behind this recommendation.
> 
> Let's take this idea to a logical extreme.  If I stand close to a large tree
> on a sunny day and photograph it with a 17mm lens, then I should use 1/30 @
> f/11.  If I move far away and frame the tree identically with a 1600 mm lens
> then I should use 2 stops less exposure???

It also says 50ASA (#25 red filter), which per Sunny-Sixteen means 
1/60s @f16 (rounded) or 1/125s @ f11; resulting in a typical bracket 
of 1/250s @ f5.6-8-11.
With #87C, 12ASA, this becomes 1/15 @ f16, or 1/60s @ f8, or a 
bracket of 1/60s @ f5.6-8-11.

Btw, partially related to 'close to subject', but with an opposite 
effect: if you stand *under* a tree, in the shade, the normal visual 
light meter reading drops several stops....while in fact, in terms of 
IR-radiation, that drop is much less severe, two stops at most, often 
less....lots of IR-radiation gets transmitted through the leafs.

(my explanation: the actual IR-reflection takes place on a much 
deeper level in the leaf, so transmission is more likely than visual 
light, which is reflected from the top of the leaf)

This means that a normal visual reading leads to severe overexposure 
(it sees much less light than there actual is in the form of IR, 
hence wants to expose more to compensate).

--                 
Bye,

Willem-Jan Markerink

      The desire to understand 
is sometimes far less intelligent than
     the inability to understand


[note: 'a-one' & 'en-el'!]

If you have any question, remark, comment, want to share some philosophy or just want to express your opinion about these pages, feel free to send email to: w.j.markerink @ a1.nl