View Full Version : Red filter

Varakan Ten Tipprapa
28-Sep-2005, 00:51
Please anyone help me,

B&W 90(25) : Filter factor is 3 = 2 stops (25 red should be 3 stops isn't it? , but B&W red 25 just 2 stop???)

B&W 91(29) : Filter factor is 8 = 3 stops ( They said a bit high contrast)

I cannot decide which one I should go for.. Mostly I'm landscape and architectural photography. I already have Yellow Orange B&W 40(16): Filter factor is 4 = 2 stops...

I read all descriptions of both, but I've never used them at the same time, I would like to know which one is more useful in general. I mean, what's typical "Red" filter should be .. I still need rich gray tone and detail in shadow as well.

Please me,

Emrehan Zeybekoglu
28-Sep-2005, 03:19
If you're doing general landscape and architectural photography, 29 and 25 may be overkill except in certain circumstances. I'd say a range of yellow and orange filters (by the way, 25 is like dark orange anyway) should be satisfactory in most situations. I think most widely used red is 25, but how often do you really need it?

John Cook
28-Sep-2005, 04:19
In terms of increasing drama, or distortion, obtained with clear blue skies, the order of the filters, from reality to fantasy, is yellow, orange, red 25, red 29.

Traditionally, Kodak manuals used to call for a medium yellow filter with “panchromatic” film to make outdoor scenes record as “normal”. (Green filter for tungsten)

The orange and red 25 are each, in turn, more dramatic than “reality”.

The red 29 creates the most distortion, with jet black (from clear blue) skies and corresponding deeper shadows (which are lit with blue skylight).

A 29 filter was used in the past by Hollywood film crews shooting b&w “day for night” shots. By carefully shooting sunlit scenes with this filter, and underexposing about two stops, it was possible to make a sunlit picture which looked like it was shot under a full moon on a clear night. The sky was black with white clouds and the shadows were empty.

This technique is fully explained in older editions of the American Cinematographer Manual:


It may very well be that “day for night” photography may be further enhanced by fiddling with the negative contrast. But I don’t believe that film crews had access to pushing and pulling their processing.

This technique can be quite dramatic, shooting into the sun at an ocean beach with the tide out and a foreground of reflective wet sand.

It is less useful in urban scenes where artificial lights are supposed to be prominent.

As far as the appropriate filter factors, each "panchromatic" film reacts to the color spectrum of daylight slightly differently and each filter manufacturer marches to his own drummer. I'm afraid a personal test (or bracket) is in order. Just remember that these filters depend upon red sunlight and blue skylight to work. A hazy sky will reduce the effect, a clear dry deep navy desert or high-altitude sky will intensify it.

28-Sep-2005, 05:17
Filters are cheap. Since you're going to do landscape you should have a whole range of them. Light and medium yellow, orange, red, green, yellow-green, and Polarizer. (I've also carried a light blue for 50 years and never used it.) The best way to evaluate their effectiveness is to actually look through them, not depend on the description in the package insert.

Bruce Osgood
28-Sep-2005, 08:15
Please anyone help me,
B&W 90(25) : Filter factor is 3 = 2 stops (25 red should be 3 stops isn't it? , but B&W red 25 just 2 stop???)

end snip

My B+W 90 has a filter factor of 5X, at least that's what it says on the ring. It is also designated as "Light Red". The compensation of 5X is 2.24 stops.

Ralph Barker
28-Sep-2005, 08:15
Schneider lists the filter factor for the 25 as 5 (not 3), or about 2.5 stops. It's probably about as deep as you'd want to go for most landscape work. The 25 is one of my most-used filters. The 29 is more useful for near infrared films, but may be too heavy-handed for conventional films and scenes - unless you're after the night effect that John mentioned.

Also, if you are just starting out, you might give some thought to deciding on one or two filter sizes that will accommodate the lenses you plan to acquire, rather than just getting filters that fit the lens you have at present. Adapter rings are far less expensive than filters, and having a "system" will save you lots of money.

Emil Ems
28-Sep-2005, 09:22

The right answer depends on the film you are using. I find that T-Max is pretty much more panchromatic than, for instance, HP5. That notwithstanding, T-Max appears to need stronger filters for a given amount of darkening of sky than HP5. Since I use T-Max I tend to use the stronger Red Filter for beautiful cloudy skies which still are far from the black skies Ansel Adams used to obtain with the same filter. What you loose however, is texture in leavy trees. For that reason, if the filter manufacturer says x8 I use factor x16.

I hope this helps

Mark Woods
28-Sep-2005, 10:20
"It may very well be that “day for night” photography may be further enhanced by fiddling with the negative contrast. But I don’t believe that film crews had access to pushing and pulling their processing."

Actually in the early days of cinemtography, the Director of Photography often went into the lab to process the film he shot that day. Floyd Crosby, when he shot Tabu on a south sea island, actually took a portable film processing machine with him that he used to process his him (won the Oscar for cinematography for that film). The lab's relationship with the Directors of Photography to this date is very close and the labs work to process the negative in any manner the DP desires. This includes pushes, pulls, cross processing, bleach by pass, etc. It's pretty amazing.

Kind Regards,

Mark Woods

Director of Photography

Varakan Ten Tipprapa
28-Sep-2005, 11:33
Thank you for all opinions..

Emil, I feel so . Once I used 90 for took picture at the lake with clear blue sky, but the film came out not so dark as I though... I plan to get 90 first and later on 91.. In case of, I want some dramatically picture.. I agree Bill "Filters are cheap."

Donald Qualls
28-Sep-2005, 11:39
"This includes pushes, pulls, cross processing, bleach by pass, etc. It's pretty amazing."

For what a Hollywood film pays for their processing, it *should* be amazing...

FWIW, the only filter I own (which I hand hold in front of my plate camera lenses when appropriate; it fits my Spotmatic's Super Takumar f/1.4 50 mm) is a #25 Light Red, for which I normally allow 3 stops on Fomapan 100. I don't use it much. I'd probably use a green, yellow-green, or yellow a lot more, but hand holding is a pain, and a filter adapter to fit a 1927-ish Tessar isn't exactly a common camera store object even if I had the budget for it.

John Cook
28-Sep-2005, 13:16
Mark, thanks for the information. While having worked in a Hollywood crew forty years ago, I am on slightly shaky ground here as my experience was only with tv commercials.

However, I would suspect that all sorts of fancy footwork is done for important film makers these days.

But my impression was that day-for-night was more common in the 30's and 40's flood of weekly B westerns. I wasn’t sure that non-heroic staff directors had that sort of clout to fool with the miles of film that must have been processed every night.

Mark Woods
28-Sep-2005, 14:24
Hi John,

The first generation of DPs did work closely with the lab since meters didn't exist. The original 35mm still camera was "developed" to shoot the scene to be photographed and "slop" processed. The DP would bracket his exposures and pick the neg that he thought was the best. The 35mm still camera and how it's been used since is history. BTW, someone mentioned the cost of processing in the labs, it actually isn't as much as you might think. The prices range from about a low of $.07/foot to a rate card of about $.12/foot. Also, the cost per foot used to be carried to only 4 decimal places, because of competition it generally now is carried out to 6 decimal places. Small budget films shoot around 80,000 feet of film. Large budget films could be anything. Some commercials have shot 1 million feet of film! Brings some life to the room full of monkeys with typewriters eventually writing a Shakespear style sonnet. Most of todays DPs only go to the lab to look at film dailies, and that is almost a thing of the past. I could go on, but this isn't Imax or Omnimax ;-)

Kind Regards,

Mark Woods

Director of Photography

28-Sep-2005, 14:44
The first generation of DPs did work closely with the lab since meters didn't exist.

Photoelectric light meters did not exist before 1932 or so, but extinction meters did, and the Sunny Sixteen rule was well known. Was the 'slop' actually due to the imprecise development methods? When film was so precious (much early film making was 70mm) it seems crazy to 'bracket' motion picture scenes. But then, such was the beginning of the whole art and craft, so perhaps the point was not how well the bear danced, but that it danced at all.

Conrad Hoffman
29-Sep-2005, 20:07
I have both a #25 and a #29, and don't find them wildly and hugely different. I'd get the #25, and if you need an even more dramatic effect, combine it with a polarizer! IMO, an orange filter often gives a better rendition with less "damage" to the non-sky parts of the scene. Remember that shadows are illuminated by blue skylight, so the scene contrast will go up dramatically when you use a red filter. Often too much so. Chances are that shadows will be underexposed without careful metering plus intelligent use of the filter factor. Just blindly plugging the filter factor isn't always the route to success.