Ronald M
Veteran
Filter factor depends on filter color, and color of illumination . Not on color of subject.
Fire off a blank frame with no filter, then the filter in question. Include a grey card.
When the density of the grey is the with/without, that is the compensation for that type of light.
If you must meter through the filter, yellow is pretty accurate, orange less so, red is way off. you will need to find a meter compensation factor with a grey board and your particular meter.
There is no point in matching densities for colored subjects because the filter is supposed to change the density. Use a grey board or faded blacktop street.
Repeat all for tungsten light.
The best way, is to meter without, apply filter, increase exposure.
Fire off a blank frame with no filter, then the filter in question. Include a grey card.
When the density of the grey is the with/without, that is the compensation for that type of light.
If you must meter through the filter, yellow is pretty accurate, orange less so, red is way off. you will need to find a meter compensation factor with a grey board and your particular meter.
There is no point in matching densities for colored subjects because the filter is supposed to change the density. Use a grey board or faded blacktop street.
Repeat all for tungsten light.
The best way, is to meter without, apply filter, increase exposure.
MrFujicaman
Well-known
Kodak filters-
K1=Wratten #6 light yellow
K2=Wratten #8 yellow
K3=Wratten #9 deep yellow
X1=Wratten #11 yellow green
X2=Wratten #13 dark yellow-green
G=Wratten #15 deep yellow
A=Wratten #25 medium red
F=Wratten #29 dark red
C5=Wratten 47=blue
C4=Wratten #49 dark blue
B=Wratten #58 green
N=Wratten #61 dark green
K1=Wratten #6 light yellow
K2=Wratten #8 yellow
K3=Wratten #9 deep yellow
X1=Wratten #11 yellow green
X2=Wratten #13 dark yellow-green
G=Wratten #15 deep yellow
A=Wratten #25 medium red
F=Wratten #29 dark red
C5=Wratten 47=blue
C4=Wratten #49 dark blue
B=Wratten #58 green
N=Wratten #61 dark green
MrFujicaman
Well-known
If you look, most filter makers use the Wratten #'s or have a cross-ref chart on their website.
Kodak Filter factors-
FF=filter factor
Tri-x
#8-FF 2
# 15-FF 2.5
#11-FF 4
#25-FF 8
#29-FF 16
T-Max 100 & 400
#8-FF 1.5
#11-FF 3
#15-FF 2
#25-FF 8
#47-FF 8
#58-FF 6
Ilford Pan-F, FP4+ and HP5+ and 400 Delta
#8-FF 1.5
#11-FF 3
#15-FF 2
#25-FF 6
#29-FF 12
Kodak Filter factors-
FF=filter factor
Tri-x
#8-FF 2
# 15-FF 2.5
#11-FF 4
#25-FF 8
#29-FF 16
T-Max 100 & 400
#8-FF 1.5
#11-FF 3
#15-FF 2
#25-FF 8
#47-FF 8
#58-FF 6
Ilford Pan-F, FP4+ and HP5+ and 400 Delta
#8-FF 1.5
#11-FF 3
#15-FF 2
#25-FF 6
#29-FF 12
MrFujicaman
Well-known
You'll also find filters marked #21, #6,#22 and #23 from time to time.
Most of these are somewhat rare.....I've never seen a #6 Wratten yellow in my life.
Hope this info helps.
Most of these are somewhat rare.....I've never seen a #6 Wratten yellow in my life.
Hope this info helps.
David Hughes
David Hughes
Hi,
The blue Wratten 80's and 82's (meaning plus a letter) are for daylight colour film used with artificial light. The Yellows, 81's and 85's are for the other way round. The aim in both cases is to correct the colour temperature to about 55500 degrees Kelvin.
Regards, David
The blue Wratten 80's and 82's (meaning plus a letter) are for daylight colour film used with artificial light. The Yellows, 81's and 85's are for the other way round. The aim in both cases is to correct the colour temperature to about 55500 degrees Kelvin.
Regards, David
MrFujicaman
Well-known
Here's all the B&W to Wratten cross-over info I have:
B&W 022=Wratten #8
B&W 040=Wratten #16
B&W 090=Wratten #25
B&W 091=Wratten #29
Oddly, I can't find any yellow/green or green filters listed for them !
B&W 022=Wratten #8
B&W 040=Wratten #16
B&W 090=Wratten #25
B&W 091=Wratten #29
Oddly, I can't find any yellow/green or green filters listed for them !
traveler_101
American abroad
This chart indicates that a FF (filter factor) of 1 = a 1/2 stop. Thus my B+W medium yellow marked FF 2x = 1 full stop, while my B+W orange marked FF 4x = 2 full stops.
http://unblinkingeye.com/Articles/BWFF/bwff.html
http://unblinkingeye.com/Articles/BWFF/bwff.html
Sparrow
Veteran
... a filter factor of x1 means almost all the light is going passing through the filter so no adjustment is needed ... like UV or Skylight and the like
Capt. E
Established
Don't forget green filters. They can enhance pink cheeks and lighten foliage
seany65
Well-known
Also don't forget: If you change the film speed rather than altering the aperture to compensate for the filter factor, don't forget to change it back once you've finished with that filter.