Re: What is Equivalence

link

ggbutcher
Members 138 posts

June 7, 2023, 4:37 p.m. June 7, 2023, 4:37 p.m.
link

@bobn2 has written:

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.

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...
link

bobn2
Team 2240 posts

June 7, 2023, 7:11 p.m. June 7, 2023, 7:11 p.m.
link

@ggbutcher has written:

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.

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.
link

Deleted Removed user

June 8, 2023, 7:09 p.m. June 8, 2023, 7:09 p.m.
link

@bobn2 has written:

@SrMi has written:

The idea is that the smaller mass of a smaller sensor is quicker to adjust.

Using the same principle we'd conclude 980kg VW Up! is quicker than a 1,888 kg Bugatti Veyron.

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.
link

bobn2
Team 2240 posts

June 8, 2023, 9:12 p.m. June 8, 2023, 9:12 p.m.
link

@xpatUSA has written:

@bobn2 has written:

Using the same principle we'd conclude 980kg VW Up! is quicker than a 1,888 kg Bugatti Veyron.

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.

Exactly, unless you state the conditions, the statement is meaningless, and as I said already:

@bobn2 has written:

a smaller sensor likely makes IBIS a bit more energy efficient, rather than easier.

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.
link

Deleted Removed user

June 9, 2023, 10:24 p.m. June 9, 2023, 10:24 p.m.
link

@bobn2 has written:

@xpatUSA has written:

@bobn2 has written:

Using the same principle we'd conclude 980kg VW Up! is quicker than a 1,888 kg Bugatti Veyron.

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.

Exactly, unless you state the conditions, the statement is meaningless, and as I said already:

@bobn2 has written:

a smaller sensor likely makes IBIS a bit more energy efficient, rather than easier.

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.

Quite so, even with the same thickness, the mass increases by the area ratio so x2.25 for upscaling a 1.5 crop sensor.
link

JACS
Members 878 posts

June 9, 2023, 10:40 p.m. June 9, 2023, 10:40 p.m.
link

@bobn2 has written:

@xpatUSA has written:

@bobn2 has written:

Using the same principle we'd conclude 980kg VW Up! is quicker than a 1,888 kg Bugatti Veyron.

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.

Exactly, unless you state the conditions, the statement is meaningless, and as I said already:

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.

Quoted message:

@bobn2 has written:

a smaller sensor likely makes IBIS a bit more energy efficient, rather than easier.

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.

JohnVickers likes this.

favorite 1
link

finnan
Members 322 posts

June 9, 2023, 11:14 p.m. June 9, 2023, 11:14 p.m.
link

HAND.

Deleted likes this.

favorite 1
link

bobn2
Team 2240 posts

June 11, 2023, 1:21 p.m. June 11, 2023, 1:21 p.m.
link

@xpatUSA has written:

@bobn2 has written:

@xpatUSA has written:

@bobn2 has written:

Using the same principle we'd conclude 980kg VW Up! is quicker than a 1,888 kg Bugatti Veyron.

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.

Exactly, unless you state the conditions, the statement is meaningless, and as I said already:

@bobn2 has written:

a smaller sensor likely makes IBIS a bit more energy efficient, rather than easier.

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.

Quite so, even with the same thickness, the mass increases by the area ratio so x2.25 for upscaling a 1.5 crop sensor.

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.
link

bobn2
Team 2240 posts

June 11, 2023, 1:22 p.m. June 11, 2023, 1:22 p.m.
link

@JACS has written:

@bobn2 has written:

Exactly, unless you state the conditions, the statement is meaningless, and as I said already:

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.

Another good point.