Playing The Long Game: Outdoor Photography With Telezooms

AF to -6ev, but what about with an F4 lens Canon?

JackAllTog Avatar
JackAllTog Plus
14 6.4k 58 United Kingdom
21 Dec 2018 11:27AM
I love the spec of Canon's new EOS-R focusing down to -6ev when using their new RF 50mm f1.2 lens.

BUT i can't find any information on what it can achieve using a more normal F4 lens - such as the 'kit' 24-105 F4 it might be supplied with?
Is it actually better than my rated -3ev EOS 6D camera with an f4 lens?

I've had a search and can't yet find anything on this, so does anyone in ePhotozine know how well AF will work with a more typical lens attached? And perhaps with non center spot focusing all well?
I'm also interested in how does the focusing work differently to achieve this?

The spec says with all its disclaimers - "During still photo shooting, f/1.2, Center AF point, One-Shot AF, at 23C/73F, ISO100"

Which brings me onto the 2nd point, its ISO range does not seem that different from previous EOS models, So actually it can't give you much more that you could see before, though it may well focus on it better.

I'm just comparing some specs at the moment, Sony's A7 III seems a little better than most for higher ISO's; though the older Pentax 645 beats everyone easily - probably as its a larger sensor.
LenShepherd Avatar
LenShepherd 15 4.7k United Kingdom
23 Dec 2018 7:59AM

Is it actually better than my rated -3ev EOS 6D camera with an f4 lens?

The implication is with an f2.8 lens on your current camera you should get -4 EV equivalent.
Then with an f2 lens -5EV and with an f1.4 lens -6 EV.
I presume Canon (like Nikon)has a technical department where you can email this type of question, with an answer usually within 1 working day.
JackAllTog Avatar
JackAllTog Plus
14 6.4k 58 United Kingdom
23 Dec 2018 11:17PM
Thanks Len, this makes it clearer to understand.

Its a shame its not an absolute measure of just the camera performance as with an F1.0 lens its even better then, I guess with an imaginary f0.0 ALL cameras are amazing. Thats a useless marketing fact.

I've never been very successful at getting in contact with Canon, Nikon on the other hand seem to look after consumer punters brilliantly.


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