diglloyd publication
Imagery: Auto - Large Table of Contents

T-stop vs 180/2.8D ED

The T-stop or “transmission stop” is an idea similar to the F-stop except that it denote the actual light transmission. The T-stop is critically important for professional film-making, where lenses must be matched to a small fraction of a stop, where even 1/10 stop is perhaps too much variance.

With still images, T-stop is generally of little importance, except that if you’re buying an f/2.8 lens with the goal of faster shutter speeds under dim lighting, then getting a lens that has a T-stop of f/3.2 or f/3.5 is self-defeating.

The original Nikon 70-200/2.8 VR was a rip-off in this regard, showing at least a 1/2 stop light loss as compared to a prime lens, documented here. That means shooting at 1/60 second instead of 1/90 second, which can be a big issue in some scenarios, such as sports. For an interesting list of t-stops, see this thread (I don’t vouch for the reliability of the figures there, and they were all done with green light).

Article continues for subscribers...

Already a subscriber? CLICK HERE TO LOG IN

Since 2006, Diglloyd Advanced Photography is the authoritative review and reference for DSLRs and their lenses: Canon and Nikon primarily, but also Pentax and some medium format. Reviews of key DSLRs are included, but the primary focus is on lens performance. Also included is a wealth of technique and workflow approaches.

DAP includes thousands of pages of exclusive coverage and high resolution Retina-grade examples detailing Canon and Nikon DSLR bodies and their lenses, with in-depth analysis of sharpness and contrast, color, bokeh, vignetting, distortion, MTF, and flare, behavioral and practical usage.

  1. Explore the table of contents
  2. View Lloyd’s Blog
  3. SUBSCRIBE NOW for $ per year.

diglloyd Home Page | Terms of Use | PRIVACY POLICY | Contact
Copyright © 2008-2016 diglloyd Inc, all rights reserved.