The idea is that the smaller mass of a smaller sensor is quicker to adjust. I do not know of any comparisons, but I feel that my m43 system has better working IBIS than my FF and MF systems.
April 29, 2023
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I don't think that's true. In my experience beginners quite often post photos they've found and ay 'how do I take photos like this'. If the photo was taken with a FF camera or larger (as they usually are) and the effect they are aiming for involves DOF, and/or 'smoothness of tone' (as it often does) then equivalence is very helpful. You can discuss that to get the same effect you don't need to use the same settings as the FF camera, but to different ones that can be calculated simply using equivalence. Sometimes thy just ask 'can my camera take pictures like this', and the same applies.
At the beginning of this site, an EXIF display on the photos was one of the most asked-for features. Why did people ask for it? My assumption would be that they want to know the settings so they can emulate if they like the photo. Again, emulating the photo doesn't involve replicating the settings if the sensor size is different from the ones they are using, but they work out which settings to use with the aid of equivalence. -
Using the same principle we'd conclude 980kg VW Up! is quicker than a 1,888 kg Bugatti Veyron.
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What you've told me is how you set the metering, not how you make your exposure decisions. I suppose that with respect to equivalence the key question is how you decide which f-number to use. Whether you had to denoise or not depends in part on those decisions.
I'm not a fan. I'm not sure what advantage it offers over straightforward DR, and I think it has baked in some dubious assumptions. The absolute number placed on DR is not so important as the ordering in which it puts cameras. Bill gives an example where 'PDR' orders cameras differently from DR but fails to say whether this is significance, that is , is the different order telling us something we actually need to know. The baked in assumptions are normalising to a very low resolution, around 1MP, and setting a very high acceptability threshold fro shadow noise. As I remember it's an SNR of 20, which is based on an ISO number ad the overall SNR for an acceptable photo. But we're not taking about overall SNR, we're talking about what is usable in the shadows, which is something like 2. The figures look reasonable only because these two questionable decisions work in opposite directions and sort of cancel out. As for whether we should credit the changed ordering more than the order DR would put them in, I don't think so.
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There should be a Godwin’s law for car analogy.
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Well, for smaller steering adjustments it is :)
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Define a 'smaller steering adjustment'.
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It would be just as invalid as the original, which is an excuse for people to avoid accurate discussion of their politics.
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Hmm, I thought I was describing my exposure decisions by telling you I let the matrix modes make the specific decisions, knowing pretty much how they behave. I think for any sort of shooting where there's subject movement and constantly changing light giving control to a well-reasoned decision-making tool is prudent. Frankly, I don't want to be fiddle-faddling with ETTR stupid pet tricks or even doing spot metering when I've got a steam locomotive heading toward me traveling through changing light. I want to concentrate on placement and timing of the objects in the scene for the best composition I can get.
Regarding Bill's PDR, that stop and a half at ISO 800 and above has proven significant in my low-light shooting. With the Z 6 I can get hand-holding shutter speeds and little-to-any appreciable shadow noise dialing up to around 1600 ISO, something I cringe at thinking of doing with the D7000. Staring at that stop-and-a-half in the PDR chart is what led me to the decision to procure the Z 6. And then, IBIS, which doesn't figure in any of the equivalence consideration, will let me hand-hold well-past my previous 1/30sec threshold, down to 1/10sec. These are the sort of mental discussions going on in my bear-of-little-brain head, comparing the D7000 and Z 6, not some arbitrary consideration of format equivalence...
Now, I realize my thinking may be a bit coarse, and my consideration set (Nikon) may over-simplify things, but I feel it has well-supported my procurement and use decisions. So, for the wider audience, it might be helpful if you could describe where that thinking might trip one up in the more general case. And be pragmatic about it, e.g., 1/2 stop differences are differences, but why would it be important?
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OK, but when I make exposure decisions I tend to determine apertures and/or shutter speeds that I want to use as the first step, and your account contained none of that - so I was wondering how you go about that part of the decision making.
I'm not sure how that relates to Bill's 'PDR' as opposed to any other DR based metric. The 'stop and a half at ISO 800' comes back to the question of your exposure decision making, because you might well not be using the same ISO setting for the same photo, depending on the camera/lens combination available. BTW, a half of a stop of that difference is due to the Z6 having a dual conversion gain sensor, and a stop down to equivalence, which of course you're not considering. Equivalence could tell you how to and if you could get the same results (within 1/2 stop in this context) without shelling out for a new camera by changing your exposure decisions.
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Don´t try to be cute. You know what I mean.
There is a reason the Veiron will never be a competitive rally car. And it has everithing to do with weight and size.For the same reason you never see a 300+ kg HD on a motocross event.
Mass vs inertia.
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I don't know how universal it is, but my anecdote is that out of the three ILCs I own with IBIS, the largest sensor seems to have the most slop/error, and the smallest sensor is the tightest (Canon R5, Canon R7, Pentax Q).
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Well, that's exactly it, I couldn't come up with an exposure strategy for the D7000 that allowed me to preserve highlights AND get acceptable shadows without post shenanigans AND keep from distracting me during the moment of capture. The Z 6 gave me that 1.5 stop AND an exposure mechanism that preserved highlights with no real-time consideration required. In practice I can even live with the 1-2 stops of headroom of the highlight-weighted matrix metering because the shadows are so much cleaner, and I can't account for that stop in the graph. And then, IBIS, which lets me collect more light with a lower shutter speed, hadn't even considered that in the purchase decision, but I'll always take lagniappe... 😆
There is a lot more to shooting than just exposure...
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and what I'm suggesting is that maybe, with the aid of the knowledge of equivalence, you'd have been able to. Or maybe not, but the process would have been much faster than unguided trial and error.
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There being no Newtonian mention in this thread yet, one could comment that a smaller sensor with smaller positioning forces can be just as quick as a larger sensor with larger positioning forces ... whatever "quick" means in this context.
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Exactly, unless you state the conditions, the statement is meaningless, and as I said already:
as in - you need to use a bit more force for the bigger sensor, which will use a bit more energy, other things being equal. Plus, of course, you aren't just moving the sensor around, but a whole sensor assembly. It doesn't scale with sensor size.
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Quite so, even with the same thickness, the mass increases by the area ratio so x2.25 for upscaling a 1.5 crop sensor.
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Yes, "quick" may not be the right term here, you may want good precision as well. A smaller sensor needs a higher precision for the same effect.
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HAND.
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Most of the sensor assembly isn't sensor. If you look at the IBIS mechanism from a camera you'll see that the sensor stack is mounted to a metal assembly that is the bit that actually has to be moved around, such as this, from the Fuji site. The metal assembly weights considerably more than the sensor itself.
If you compare these sensor assemblies you find that the difference in size between them is smaller than the difference in sensor size, that is, smaller sensors tend to have relatively more metal around them. -
Another good point.
