nnowak
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Veteran Member
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Posts: 9,074
Re: …Said the quiet part out loud
3
MAC wrote:
nnowak wrote:
MAC wrote:
nnowak wrote:
MAC wrote:
R2D2 wrote:
MAC wrote:
R2D2 wrote:
kenta101 wrote:
MAC wrote:
55-62mm = f/5
63-84mm = f/5.6
85-142mm = f/6.3
143-210mm = f/7.1
whereas the 55-250 stm
55-63mm = f/4.0
64-99mm = f/4.5
100-154mm = f/5.0
155-250mm = f/5.6
a pathetic aperture range
Might be time to shift to the other side of the paradigm? The cameras can autofocus at these apertures, the software can process the required ISOs, and our wallets can all benefit.
R2
there are FF and Crop options in the new paradigm
R8/R6II/R5 + RF 100 - 400 F5.6 - F8
or
R10/R7/R50 + RF-s 55-210 F5 -F7.1 = FF equivalent of 88 - 336 F8 - F 11.4
FF for me
Yeah, these once thought of as “slow” lenses can really perform!
R2
focus acquisition spec:
R50/R10 -4EV
R7 -5EV
R8/R6II -6.5 EV
the R8 has a whopping 2.5 stops better focus acquisition in low light that is 2.5 X 2.5 = a whopping 6.25 times the amount of light
add that to the 2 stop advantage of the FF 100 -400 on FF over the crop counterpart analysis above, that is a total whopping 2.5 stops + 2 stops = 4.5 stops or a whopping 4.5*4.5 = 20.25 times the amount of light advantage --
wowsers -- that be a whoooooping!
The only thing "that be" is a mathematical disaster. Crop factors and equivalence don't figure into focusing brightness range comparisons. The difference between the bodies is a matter of simple subtraction. R8 vs R7 is 1.5 stops and R8 vs R50 is 2.5 stops. Since the RF-S 55-210mm is 1/3 of a stop faster than the RF 100-400mm, and the EF-S 55-250mm STM is a full stop faster, much of that low light AF advantage is negated. The R8 is still better, but it is not 20.25 time better. Not even close.
nice, first post in R forum in three years- thinking about buying one
No. This thread was linked in the M forum.
RF 100-400 on R8
100-122mm = f/5.6
123-155mm = f/6.3
156-258mm = f/7.1
259-400mm = f/8.0
RF-s 55-210 on R50
55-62mm = f/5
63-84mm = f/5.6
85-142mm = f/6.3
143-210mm = f/7.1
First of All -- The sensor of the R8 is a lot nicer than the R50 😉
https://www.photonstophotos.net/Charts/PDR.htm#Canon%20EOS%20R10,Canon%20EOS%20R6%20Mark%20II
I think you are saying equivalence doesn’t matter, I’m saying get similar FOV and multiply F stop by 1.6
No, I am saying that equivalence and crop factors have absolutely no bearing on low light AF ratings. In terms of equivalence and the above lenses, the R8 has a one stop advantage over the R50. Not 2 stops, not 2.5 stops, and certainly not 4.5 stops.
R8 vs R50 is 2.5 stops EV low light focus capabilities - that is 2.5 squared or 6.25 times the amount of light that the R50 needs to focus against the R8 in low light.
Only if you are using the same apertures on both bodies, which you are not.
the lenses are much more complex than you calculate - they are different animals - the crop lens gets further crushed if it tries to crop to a 400 fov to match the FF 400 mm
Just adapt the EF-S 55-250mm f/4.0-5.6 STM. No need to crop for 400mm equivalent and the lens is a full stop faster than the RF 100-400mm. Now, your AF advantage is down to 1.5 stops and equivalence is basically equal.
$1499 + $649 versus $679 + $99 + $299. The crop kit is half the price and gives up very little in terms of image quality. You could swap the R50 for the R7 with more pixels, bigger buffer, weather sealing, dual card slots, IBIS, and a real battery, and you would still be money ahead.