Anyone tested R5(6) + TC 1.4x III + 400mm f/5.6L ?

Bdbtoys

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Is it not true that IBIS is most effective on shorter lenses, and that it doesn't do so much for extra long lenses? It might help a bit when added to the lens's IS, but it not a substitute for it.

I love questions where I am genuinely intrigued by what the answer might be. In contrast, I believe that longer focal lengths would get more usage out of IBIS than a shorter once due to the perceived magnification of camera movement at longer lengths. But it really looks more lens based...

Per Canon spec on the applicable lens pages and then here for IBIS...
1628350621619.png
15-35/2.8 has 5 w/IS, and 7 w/IS+IBIS
50/1.2 has no IS, and 7 w/IBIS
85/1.2 has no IS, and 8 w/IBIS
70-200/2.8 has 5 w/IS, and 7.5 w/IS+IBIS
100-500/4.5-7.1 has 5 stops w/IS, and 6 w/IS+IBIS

So comparing just about any lens to the 100-500 supports your theory... but comparing others such as the 15-35 > 70-200 or the 50 > 85 doesn't. It would be nice to see the data points on other long lenses.

Note: There is also the image circle of each lens in play here too as that matters as well when dealing with IBIS.
 
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stevelee

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So comparing just about any lens to the 100-500 supports your theory... but comparing others such as the 15-35 > 70-200 or the 50 > 85 doesn't. It would be nice to see the data points on other long lenses.

Note: There is also the image circle of each lens in play here too as that matters as well when dealing with IBIS.
So it is a generalization, but apparently most of the work is done in lens with longer lenses. And of course longer lenses need the stabilization more than shorter ones. That is acknowledged in the reciprocal rule of thumb for shutter speeds.
 
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stevelee

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I find 1/1000s too slow in general for BIF with IS on and don't get tack sharp images unless the bird is very lazily floating across, so usually have 1/2500-1/4000s, and the IS isn't contributing much if anything at all to sharpness. With the 5DSR and 100-400mm II, I use the centre 9 points and never have much difficulty getting focus. With the R5, the full screen tracking just picks up birds quickly whenever they are in view, and the IBIS is of secondary importance. I've recently searched the net for the effect of IBIS on the 400/5.6 L and haven't found anything.
To me, sharp BIF pictures don't look like the bird is flying. I realize that is contrary to the views of BIF fans.
 
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AlanF

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To me, sharp BIF pictures don't look like the bird is flying. I realize that is contrary to the views of BIF fans.
How do you define sharp for BIF? There's a difference between blurring movements of the wings, which can show motion and can even enhance a shot, and the eye and beak not being sharp.
 
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Here is my experience with a 5DsR and the 1.4 TC III on a 400mm f/5.6 vs. 100-400 II. I am talking about one sample of each lens, and one 50mp body. While I don't use the TC very often on the zoom, the image quality is fine. On the other hand I found the chromatic aberration a big problem with the TC on the 400mm prime. Any extra reach was negated by the added CA.

Personally I still prefer the prime for BIF over the zoom. Maybe if the zoom had an additional 10m minimum focal distance limiter, focus would get lost less often in the sky, For me anyway, it is easier to reacquire focus for BIF with the prime set to 8.5m minimum focus distance.

I would like to hear some real world experience as to the advantage of IBIS with a 400mm lens. If I purchased an R5 and EF to RF adapter, what would I gain when shooting raptors that perch around my house and then take off in flight? I usually have to shoot at 1/1000 for hawks and eagles on the wing.
If you do purchase an R5 then from what I've read so far it would be a good option to sell the EF 100-400 and get an RF 100-500.
 
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Bdbtoys

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So it is a generalization, but apparently most of the work is done in lens with longer lenses.
For the first part, I realize it was a generalization... however, after seeing the data, I can't say I agree (for at least the RF lenses). In all the examples I semi-randomly picked out, they all start with either 5 stops of correction or none. The amount that IBIS added changed... with longer focal lengths getting more stops of correction from IBIS than the shorter counterparts (with the exception of the 100-500).
 
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stevelee

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How do you define sharp for BIF? There's a difference between blurring movements of the wings, which can show motion and can even enhance a shot, and the eye and beak not being sharp.
Yes, it sounds like you likely know what I meant, shots where the tips of the wings show no blur at all. A long-time online friend gets criticized at his photography club if there is the slightest blur. That’s fine for eagles and other soaring raptors. And I guess about all birds soar sometimes. They just don’t hold still to pose for pictures.

I admit to liking some BIF shots, but don’t share a passion for looking at most of them, much less the level of interest in taking them that inspires some of you guys to spend significant time and money on that pursuit. I have no quarrel with those who do, of course. I just throw in an opinion from time to time.
 
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AlanF

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Yes, it sounds like you likely know what I meant, shots where the tips of the wings show no blur at all. A long-time online friend gets criticized at his photography club if there is the slightest blur. That’s fine for eagles and other soaring raptors. And I guess about all birds soar sometimes. They just don’t hold still to pose for pictures.

I admit to liking some BIF shots, but don’t share a passion for looking at most of them, much less the level of interest in taking them that inspires some of you guys to spend significant time and money on that pursuit. I have no quarrel with those who do, of course. I just throw in an opinion from time to time.
And getting a sharp eye and beak is why I rarely shoot as low as 1/1000s for BIF.
 
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