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Thread: Cine lenses for still imaging

  1. #1
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    Cine lenses for still imaging

    Like the topic says. How well cine lenses work for still images?

    The other thing on those is the T value versus F value. How could i best solve what is example t1.5 as f?

  2. #2
    Super Moderator Kayaker72's Avatar
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    Cine lenses should work great for still images. If I ever went deep into portraits, it was something I would consider for a different look. I have been surprised to only see 1 or 2 photographers try this. Granted, the cine lenses are very large and very expensive.

    My understanding: T stands for transmission. It is the actual measured light that makes it through the lens normalized to be equivalent to F-value. But it is real. F stops are calculated, being the focal length divided by the aperture diameter. But the values often rounded. For example, here is a recent patent on RF f/1.8 lens, most of the reported f values in the patent are actually 1.85. I've seen worse go by. So just like reported focal lengths are usually rounded up, reported F-values are usually rounded down. Photographers over the years have accepted this. However, cinematographers often have different lenses shooting the same scene or transition from one scene to the next and put a higher priority on exposure continuity, thus the industry responded given them T-stops where T-1.5 is the actual light coming through and T-1.5 is T-1.5 regardless of the lens. DXO actual measures the transmission of lenses, here is a recent write up on the RF 24-105. You can see it is actually a T 4.2-T-4.4 lens. Which is actually very good. I've seen lenses where the T-number is 2/3 stop different from the F-Number.

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    This is the lens that got me bondering https://irixlens.com/cine-lenses/21mm/

    For me stills are the main thing on nighttime shooting but this might be quite good option here in southern finland for northernlights since not the widest but wide enough and nice t1.5 should be goodish for live videos aswell on night time. Lens is well protected and also irix is good quality.

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    Super Moderator Kayaker72's Avatar
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    That makes sense to me. Basically a 21 f/1.4 lens (as most f/1.4 would have a t~1.4). Have you seen any reviews on the optics? My only curiousity is that video lenses may not need to be as sharp as photography lenses with FHD being equivalent to 2 MP and 4 K being about an 8 MP file in 16:9 and 10 MP file normalized to 4x6 format. It isn't until 8K that you really start talking about those lenses being needed to resolve details we are used too at ~33 MP in 16:9 and 39 MP equivalent in 4x6 format. Even if you can't find a good review, if they have a good return policy, you could check it out and return if not up to your standards.

    BTW, 11 aperture blades, it should have some beautiful bokeh and smooth rendering.

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    That was announced...was it thursday so not much luck on reviews yet.

  6. #6
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    My understanding is that you need to check the optical formula. Often times it is identical to the photo lens. Thebother difference is focus throw is longer and tighter, the aperture is clickless and continous.
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