Most of the novice photographers and videographers, after getting familiar with a few basics, think that they have mastered the art. However, this is far from reality. The truth is the learning curves involved in video-graphing as well as photography never ends. It only evolves and gets better with time.
Whether you are a professional or an amateur, you should try to get acquainted with all digital photography tips, including the T-stop and the F-stop. As well as keeping you educated, each and every detail associated with a T-stop and an F-stop will go into making you a better photographer/videographer.
Difference between an F-stop and a T-stop
When it boils down to photography, F-stops are a common term. As more photographers start delving into the world of videos, they have started using cinema lenses. This has resulted in a new trend and professionals are switching to T-stops. So, what does that mean? Aren’t T-stops and F-stops the same?
Well, it is a bit difficult to explain the difference between these two terms in a single sentence. You need to comprehend the terms separately and then compare them to understand their differences. That will ensure ease of understanding of T-stops and F-stops and their usage.
Basically, an F-stop is a math equation. It is based on the lens’ focal length relative to the size of the opening through which light enters. A T-stop, on the other hand, is the measurement of light that is transmitted through the camera lens.
Suppose a lens of 100mm has a 25mm aperture opening at F/4. That same lens will have a 50mm aperture opening at F-2. Twice the diameter implies four times the area. So the amount of light getting inside actually doubles.
The aperture and focal length relationship allow a particular amount of light through the camera lens. That is why a 50mm lens with F/1.4 has a smaller aperture compared to a 105mm lens with F/1.4 but still allows approximately equal amount of light to touch the sensor.
Previously, this was a consistent and reliable measurement. When glass had little to no coatings and lens design was simple, the amount of light loss was minimal. If you pick a few different lenses with the same aperture, you won’t be able to distinguish between them.
However, you will come across various lens designs and different coatings today that light gets lost all over the place. If you happen to pick five to six camera lenses at F/4 (from the same maker), they will produce different exposure in the same settings. While the differences are not very big, they are noticeable. The slight differences are not a big deal to many photographers.
In case you use the in-camera meter, the sensor will take care of these differences and compensate for the lost light. It might tell you to snap 1/125th of a second with one camera lens and 1/150th of a second with the other lens without changing the aperture, scene and ISO. The sensor will see the actual light being transmitted through the camera lens.
On the other side, the T-stop is the actual measurement of the light that gets through the camera lens. While F/4 might produce different results on different photography lenses, T-4 will generate identical results across the board on all lenses. At least, you can be sure of identical results for known brands of cinema lenses.
Cinematographers Shooting Scene
Unlike photography professionals, cinematographers often shoot the same scene using multiple cameras, multiple lenses from various angles. As such, those slight differences are easily noticed when switching from one shot to another. Although these differences can be corrected and rectified in editing, it warrants a lot of legwork, especially while picturing a 90-minute movie.
As an example, the transformers movie has an average shot length of 3- 3.4 seconds. This means approximately 1,500 to 1,800 clips in total. The cost, as well as time associated with fixing inconsistencies in those clips, can add up quickly. The good news is modern technology has helped to resolve this issue.
Monitors like Aputure VS5 have built-in false color, RGB parade, and many other features to find out what the sensor sees to obtain consistent exposure from one shot to another. This is why many professionals opt for mirrorless and DSLR cameras with clean HDMI output. These types of monitors help you to get along with the issue of inconsistency.
However, they still add extra time in shooting itself. You have to double check and fix those inconsistencies as required. In case you don’t do that while capturing, you will have to do it on a computer. If you have a small team, you could be overwhelmed with the amount of time required for fixing the inconsistencies.
If you are doing some personal projects, it might take a much longer time for editing. On the other hand, the cost and time required for such edits will be much higher in the case of a high budget movie. These problems can be easily averted with the use of T-stops. All you need to do is put a T4 into lenses, and they will get a consistent and reliable exposure.
You don’t have to keep guessing on the usage of lenses or waste time taking more measurements on the set. With the T-stop, you can ensure that the camera is seeing what you expect to see. In the case of photography, you can resolve the issue of inconsistency to a great extent (not completely) by using lenses from top rated brands.
Finishing Thoughts
Learning important digital photography tips is paramount to excel in the field. This is even more correct with respect to details such as an F-stop and a T-stop. A single mistake on your part could cost you dearly. On the other hand, a simple minute detailing can impact your work positively.
This is why professionals never overlook the importance of any parameters whether it is the T-stop or the F-stop. If you wish to be one of the successful photographers/videographers, get familiar with the basic differences between an F-stop and a T-stop and use the parameters appropriately to get the best results.
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