Questions tagged [light-transmission]
The light-transmission tag has no usage guidance.
19
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Transmission rate of vintage Petzval type lenses
Is anyone aware of a transmission rate test for vintage lenses, such as 1800's Petzval lenses?
- 31
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1
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How can the EVF be brighter than the lens?
When I use my mirrorless camera, an Olympus OM-D EM1 Mark II, in a dark room, the EVF shows the room as though it is fully lit, but the lens does not have the same brightness.
It's as though the EVF ...
- 1,874
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149
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Why isn't glass transparency part of the exposure calculation? [duplicate]
The F number is a ratio calculated purely from the focal length of the lens and the size of the aperture. Any light meter talks in terms of F, Shutter, and ISO.
Different glass, or just different ...
- 821
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Does the T-number account for lens vignetting, or only for glass/coating transmission?
Surprsingly I could not find information on this. Many lenses have vignetting profiles available. Vignetting changes if you use a cropped sensor, or, in case of zoom lenses, can change with zoom.
...
- 165
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2
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Transmission, Aperture, and Focal Length in Low Light Situations
I've been looking for an affordable lens I can use for nighttime shooting, including astrophotography. The two lenses I have found that seem best suited for this are the Samyang 16mm f/2 and the ...
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Can a larger format lens provide more light to a crop sensor for a given f-stop?
Having recently spent some time fighting for light with a high-speed camera having a CS mount and a sensor area under .1 inches2, I was wondering if the f rules apply to cropped sensors?
For example: ...
- 3,603
4
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5
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F-stop vs T-Stop - how do I quickly grasp a videographers view of the world?
I'm aware this is flirting with video rather than photography, but the question really relates to how each world can be understood by the other.
Very briefly - I am an amateur photographer who ...
- 23.4k
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Why does my one lens have different exposure (t-stop) than my other lens?
I have been comparing my Pentax Takumar 28mm f3.5 lens (via an adapter) to my Canon 18-55mm 3.5-5.6 IS lens.
When I have them both set to the exact same f-stop, the exposure meter of the camera is a ...
- 1,048
7
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2
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602
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What is the T Stop of a Human Eye?
I was reading that the maximum F number of a human eye, if treated the same way as a camera lens, would have an F number of 2.1, but basically since the eye cannot be treated the same way as a camera ...
- 1,135
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Why are DSLR lenses measured in F stops instead of T stops?
I understand the difference between f-stop and t-stop, but why are cinema lenses measured in one, and dSLR lenses measured in another?
- 718
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Why does Rosco's filter page show that 33% transmission is 1 stop rather than 50%?
I was taught that each stop halves/doubles the light throughput. So one stop up is double as much light, one stop down is half as much light.
Now, according to this Rosco table: https://www.rosco.com/...
- 1,394
3
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2
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958
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Can I use my camera to measure lens light transmission?
I want to compare and quantify the light transmission of various lenses (with some custom modifiers). So I have a target setup with constant illumination, and a camera body for them ready to shoot ...
- 3,603
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What is the fastest T Stop available?
What is the widest T Stop possible We are having f stops of below even 0.7 NASA lenses What will be the T stop of such lenses with f stop below ONE?
3
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How to compare the speed of lenses taking transmission into account?
When comparing the speed of two lenses, you almost exclusively hear about the maximum aperture. This of course makes sense, since at a certain lighting condition, a larger aperture in general allows a ...
- 304
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Is there any practical way to measure the T-stop of a lens?
T-stop measures actual light transmission in a lens. Therefore, different f/2.8 lenses can have different T-stops. T-stops are usually only given for cine lenses. For photography lenses, is there any ...
- 2,571
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