The Tiffen 3 x 4" Decamired Red 1.5 Warming Glass Filter - For those who want a sure-fire way of getting accurate color temperature readings, the decamired system is the way to go. Using this formula, you can transpose temperatures from one point to another easily and quickly. This system is also useful when you wish to bring a certain amount of creativity to color photography.

Applications include keeping color temperature constant during the course of the day and producing the effect of different times of day. Available in two series, reddish filters that warm the light and bluish filters that cool the light. Each series contains 4 densities: 1.5, 3, 6, and 12. Filters in the same series can be combined.

Decamired filters are designed to more easily handle unusual color temperature variations than the previously mentioned filters. Available in increments of both a red and a blue series, Decamired filters can be readily combined to create almost any required correction. In measuring the color temperature of the light source, and comparing it to that for which the film was designed, we can predict the required filtration fairly well.

A filter that produces a color temperature change of 100K at 3400K will produce a change of 1000K at 10,000K. This is because the filter relates to a visual scale of color. It will always produce the same visible difference. A color change of 100K at the higher temperature would hardly be noticed.

Calculations
To use this concept, subtract the mired value of the light source from that of the film. If the answer is positive, you need a reddish filter; if negative, use a bluish filter. Mired-coordinated filters are termed as decamireds. Mired value divided by ten yields decamireds. The 60 mired shifts, above, would be produced by an R6 filter, where the higher values were that of the lighting.

Sets of such filters generally come in values of 1.5, 3, 6, and 12 decamireds in both B (bluish) and R (reddish) colors. These numbers are additive; that is, a pair of R3's produces an R6. An R6 plus a B6 cancel each other out to produce a neutral gray.

Used for Temperature Control    Available in Specific Increments    Warming and Cooling Variety

The decamired system has an advantage over the Kelvin system in that the Kelvin scale is not linear

Decamired readings provide more accurate/controllable readings than Kelvin

The difference between the Mired value of the film and the Mired value of the light is the Mired value of the correction filter that correctly tailors the light to the film

Related Questions and Answers

Q: 1. Hi, the graduated nd included in the set, which graduation is ? 0.3, 0.6 or 0.9 ? In order to know which ones I shuold buy separately. ThanksMariano

A: The graduated neutral density filter included in the Cavision Set of 4x4 Glass Filters kit would be a 2-stop 0.6 Grad ND Filter.

Q: 2. Why is it MORE expensive to buy just the filter without the adapter included?

A: While Canon sets the MSRP on their items, as of the time/date of this reply, the cost of the Canon Drop-In Variable ND Filter A (1.5-9 Stop), BH #CADIVNDFA, and the Canon Drop-In Filter Mount Adapter EF-EOS R with Variable ND Filter, BH #CAMAEFRFDIND, on our website are currently the same price. However, I would simply recommend that if you are certain that you want the Variable ND Filter, as it is the most expensive of the filter options that are compatible for use with the Canon Drop-In Filter Mount Adapter EF-EOS R, I would simply recommend to purchase the adapter kit that comes with the Variable ND filter, the Canon Drop-In Filter Mount Adapter EF-EOS R with Variable ND Filter, BH #CAMAEFRFDIND.

Q: 3. Does the variable ND drop in filter fit in the Canon ef -R 0.71 speed booster?

A: No, the Canon Mount Adapter EF-EOS R 0.71x (seen here: https://bhpho.to/3OmrCw5) does not accept the Canon Drop-in Variable ND Filter A.

Q: 4. Is there a non-variable ND drop in filter for this mount? Like a set of multiple NDs? I can't stand the color shift and increased contrast variable NDs create. I'd much prefer to just carry around a few drop in's at varying ND levels

A: We're afraid not. At this time Canon does not offer any alternative ND Filters for this system.

Q: 5. Hi does this set come with a filter pouch?

A: Yes, the Cavision set of 4x4 Glass Filters comes with a filter pouch.

Q: 6. What is a recommended storage case for the filter when not in the adapter?

A: A Domke 11x11" Color Coded Protective Wrap (Gray), B H # DOPW11G would be a suitable option to store this filter. https://bhpho.to/3t8GR0O

Q: 7. Is this a series VI drop-in filter that goes between a retaining ring and front of the lens (Leica R35/2.8)?

A: Correct, the Heliopan Series 6 Skylight KR 1.5 (1A) Filter is a series 6 (VI) filter and attaches to the lens via an adapter and a retaining ring. Note it does not come with those parts.

Q: 8. Can these things handle heat from tungsten fixtures without melting?

A: The Rosco CalColor Filter Kit (1.5 x 5.5" Sheets) was mainly created for flash photography. One can use the filters with hot lights using a barn door bracket as far from a hot light as possible, with room for ventilation, and a fan if possible.

Q: 9. Does it come with a protective plastic case?

A: A protective case is included with the Heliopan 58mm KR 1.5 Skylight (1A) Filter.

Q: 10. Will this drop in the Canon 300mm 2.8 just like the Polarizer Filter will?

A: Canon Drop-In Variable ND Filter A (1.5-9 Stop) is compatible only with the Canon Drop-In Filter Mount Adapter for EF-EOS - R lenses. It will not fit on Canon EF 300mm f/2.8L IS II USM Lens. You can use fixed ND filters with the following product: 1-Canon - Drop-In Filter Holder for 52mm Screw-In Filters BH #CAFHS52 https://www.bhphotovideo.com/c/product/186092-REG/Canon_2612A002_Drop_In_Filter_Holder_for.html/accessories