Quote:
Originally Posted by Jose
So if I put a 2x extender in a 200 mm lens it does not become a 400mm focal length lens? The image is 2x larger? Does not a 1.6X sensor does the same other than preserving the original f stop of the lens?
And yes, I do concur tha the original lens focal lens remains the same but the use of the 1.4X extender or the 1.6X sensor alters its original focal lenght.
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A teleconverter does actually affect the focal length, since there are lens elements involved. An extension tube does not, but merely allows closer minimum focusing distances. Sensor format does absolutely nothing to the focal length of a lens. All Canon flashes provide full coverage at the FL specified when zooming, regardless of format. It does this be being calibrated for a full frame FOV at those FL increments. Since an APS-C sensor is a field of view crop camera, the area is smaller, and therefore no adjustment is necessary.
Again, I don't see the issue. If you want to make a comparison of flash coverage between two different sensors, then I suggest setting the camera on a tripod, use manual flash only, and do not move the camera when switching bodies, and you'll see that there is zero difference in the exposure. ETTL-II along with differences between camera distance to subject between formats introduces to many variables to be considered anything viable.