RF extender experiences with RF 100-500 1.4x vs 2.0? Locked

John Sheehy wrote:

frostybe3r wrote:

John Sheehy wrote:

frostybe3r wrote:

But EF lenses are still uncontended in wildlife photography/videography, sure the new RF lenses are great for other stuff but until RF mount has a big white and 1DX R1, as suggested, I'm not switching to EF for that aspect, even when the RF whites come out, there won't be a need to change unless the sensors increase to 90mp.

People are continuously trying to say you can just use higher ISO, the aperture doesn't matter, eh, yeah it does for subject separation and shutter speeds whilst trying to avoid potential noise in your image.

No, it doesn't. F-numbers do not show up in images. Apertures do, but what you're calling aperture is actually f-number or f-ratio.

The apertures of 400/5.6, 500/7.1, 700/10, and 1000/14 are all the same aperture, and from the same distance, give the same DOF on the subject, the same diffraction blur size relative to the subject, and the same total light coming from the subject per millisecond.

A 500f4 with 1.4X extender at 700 5.6 doesn't give the same results as a 100-500 with 1.4x at 700 f10, even if you put the prime at f10 aswell.

You are substituting a larger aperture lens for a smaller aperture lens, which has absolutely nothing, nada, or zilch to do with the question of whether someone has one and not both of the lenses with them will benefit something from a TC instead of cropping. If the question were, "which lens gathers the most light, is the sharpest, has the greatest background blur, and gives the least diffraction at 500mm, 700mm, or 1000mm wide open", then you would have a point, and I would not disagree, but we were talking about image quality parameters changing when adding a TC to a given lens.

I use a very sharp lens much of the time; the Canon 400/4DO II, a lens that I chose because of its weight, over a 500/4 or 600/4 lens. It is f/4 at 400mm, or it has about a 100mm entrance pupil, they way I prefer to think of it. I also have a Sigma zoom that is 400/6.3 at max focal length (about 63mm). I get more "extra detail" with the 2xIII out of the DO than I do with the Sigma, but when I do choose to take the Sigma with me some days for the zoom versatility, relative lightness, or closer focus, I still use the 2xIII sometimes, because it is still a little better than cropping from the bare zoom at 400/6.3. Quadrupling the ISO with a 2x is not a problem because the results don't need to be magnified as much as a crop would. In a certain range of ISOs, a quadrupling may look a little nosier with default conversion parameters, than the bare lens at 200%, but is due to presentation issues of default conversion, and not due to the underlying information, which one can render how they want with a RAW converter. For JPEG shooters, they may choose more "High ISO Noise Reduction" to keep the bright and dark dots in the noise more suppressed, while still maintaining the higher subject sampling rate, if they will be leaning towards higher ISOs with their optical choices.

Zooms suck for using extenders, you can say all you want but the fact is you're trying to justify using a f10 lens in bad weather just because the aperture is the same without the extender.

It doesn't matter; there is some subject gain and no significant loss, especially with a quality TC. You are conflating the issue of main lens choice with the choice of teleconversion of any given (and already-chosen) lens, as the topic of discussion. You are also conflating f-ratios with apertures, and apertures are circle sizes, not ratios, and are where photographic qualities actually come from.

This has been about TC use "IF" you have a given main lens; not, "what main lens would you choose with no regard to price, size and weight, especially knowing that you would use a TC", in which case, I would not disagree with you about the superiority of your prime at 500mm, 700mm, or 1000mm compared to the 100-500 at those focal lengths, assuming that one wanted shallowest possible DOF, sharpest focal plane, and the most subject light collected.

Just because your £3,000 lens is 7.1 without an extender doesn't make it fine to use with an extender at 10 just because it's 'the same just different focal length but like light is same with and without extender', no, it isn't either as your extender also removes a stop of light.

-_-

A 1.4x removes a stop of exposure, with the same shutter speed. It does not remove a stop (1.4x) or 2 stops (2x) of total subject light, unless you step back 1.4x or 2x as far from the subject, which actually necessitates doubling any shutter speed to maintain the same camera shake blur size relative to subject size, which, if needed, reduces both total subject light and exposure.

This is the noise at 12800 ISO on an R5... And going off by that, I wouldn't want to touch an RF 100-500 at f10 for anything other than bright days but that's just me..

4000 for comparison