The 4.5" Round Decamired Blue 12 Cooling Filter from Tiffen is for those who want a sure-fire way of getting accurate color temperature readings. 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.

Decamired filters are used to maintain consistent color temperature during the day's shooting. Decamired filters are available in two series - reddish filters that warm the light and bluish filters that cool the light with each series available in four densities: 1.5, 3, 6, and 12. When filters from the same series are used, they can be combined.

Decamired filters can be readily combined to create almost any required color correction. In measuring the color temperature of the light source, and comparing it to that for which the film was designed, required filtration can be easily calculated.

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 Accurate Temperature Control    Filters Can Be Combined to Control Color    Made in Specific Increments    Available in Warming and Cooling Variety    ColorCore Glass    Made in the USA    10-Year Warranty

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 balances the light to the film

Related Questions and Answers

Q: 1. At what focal length (35-75) does the lens Change to F4.5?

A: It starts to change approximately 1/3 of the way toward the long end of the focal length. Note f3.5-4.5 is not that large a difference in most uses.

Q: 2. Is this lens compatible with a EOS M50?

A: The Canon M50 camera uses EF-M mount lenses but the 24-50mm lens is an RF mount lens. This Canon 15-45mm EF-M lens would be the most similar option for the M50: https://bhpho.to/3IRc3ws

Q: 3. Minimum focal distance is 0.8 inches, and it does not focus at infinity, so What is the Maximum focal distance?

A: I WOULD RECKON THE MAXIMUN FOCUS DISTANCE IS NOT DIFFERENT THAN THE MINIMUM, THIS LENS IS SIMILAR TO THE OLD zEISS LUMINARS AND lEITZ PHOTARS, DESIGNED TO WORK AT SPECIFIC DISTANCES AND NO WHERE ELSE. SO FAR, RESULTS SEEM TO BE VERY GOOD.

Q: 4. Will this fit a FUJIFILM XF 70-300mm f/4-5.6 R LM OIS WR with camera body attached?

A: The Manfrotto Advanced III 3L Camera Holster (Medium) can accommodate the FUJIFILM XF 70-300mm f/4-5.6 R LM OIS WR lens with a camera body attached, depending on the specific camera.

Q: 5. Will this case fit a Nikon z6 II with the 70-200 Z lens attached with the lens hood in the stored position?

A: Manfrotto Advanced III 3L Camera Holster (Medium) BH #MAMBMA3HM has Interior Dimensions 8.9 x 6.3 x 3.9" / 22.5 x 16 x 10 cm so it will not fit the Nikon Z6 II with the Nikon NIKKOR Z 70-200mm f/2.8 VR S Lens BH #NIZ7020028 which is 8.66" long.

Q: 6. Will a Canon EOS R5 with a Canon RF 100-500mm f/4.5-7.1 L IS USM Lens mounted fit inside of this?

A: Yes the Manfrotto Advanced III 5L Camera Holster (Large) will hold that equipment but it will be tight depending if you have the lens hood on the lens and also a neck strap on the camera.

Q: 7. Will this fit a FUJIFILM XF 70-300mm f/4-5.6 R LM OIS WR with camera body attached?

A: The Manfrotto Advanced III 2L Camera Holster (Small) would be to small to hold a Fujifilm camera with the FUJIFILM XF 70-300mm f/4-5.6 R LM OIS WR Lens attached. The larger Manfrotto Advanced III 3L Camera Holster (Medium) would be a better fit.

Q: 8. I have a s5ii. anyone have experience using the lens for video and how it tracks with autofocus?

A: The Panasonic Lumix S5II works well when using the Panasonic Lumix S 70-300mm f/4.5-5.6 MACRO O.I.S. Lens in video mode.

Q: 9. Hi. Will this work on a canon rebel t5i

A: Yes, it will work with your camera. With this super macro lens, you focus by moving the camera

Q: 10. Would this lens work on my Nikon D3400 body and would you recommend a focus rail even with a solid tripod?

A: Yes it will work with D3400 , focus rail will help .