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Full frame equivalences for lenses
- Thread starter Alan Sh
- Start date
rsn
Senior Member
Yes.
Technically it would be closer to f/4.2 as the difference between Fuji crop and full frame is a bit more than 1 stop, but yes, you are correct. Since no one will notice a difference of 1/4 of a stop, rounding to just 1 stop is close enough.
Pennyfan
Leading Member
This is wrong, technically.
f/2.8 is f/2.8, you don't apply crop factor to aperture.
The bokeh (depth of field) will appear similar to that of a full-frame (FF) camera shooting at f/4, but this is due to the difference in shooting distance relative to the sensor size.
If the shooting distance remains the same, cropping a portion of an image taken with a full-frame camera and a 24mm f/2.8 lens will produce a very similar result to an image captured with an APS-C camera using a 24mm f/2.8 lens.
Likewise, without altering the shooting distance, using a full-frame camera with a 35mm f/2.8 lens will yield a similar composition but with a shallower depth of field compared to both of the cropped version above.
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I was thinking more of the amount of light.
So, say on a Fuji, I set it to 16mm at F2.8, ISO 200 and 1/100th - and that made a nice picture. On a full frame camera, to get the same 'nice picture', would I set it to 16mm, F4, ISO 200 and 1/100th?
Alan
So, say on a Fuji, I set it to 16mm at F2.8, ISO 200 and 1/100th - and that made a nice picture. On a full frame camera, to get the same 'nice picture', would I set it to 16mm, F4, ISO 200 and 1/100th?
Alan
Almost. The matching full frame exposure would be 24mm, f/4.0, ISO 400 and 1/100
- Same angle of view
- Same depth of field
- Same noise levels
- Same dynamic range
- Same motion blur
No, it is not wrong. Equivalence is all about creating final printed images that match as close as possible.
- Same angle of view
- Same depth of field
- Same noise levels
- Same dynamic range
- Same motion blur
Morris0
Forum Pro
You will never get the same noise level between two cameras of different type or brand.
Exposure is exposure. The exposure triangle does not care about the size of the film or sensor.
Morris
They call it "circle of confusion" for more than one reason!
This topic has been debated endlessly, and the answer isn't simple. No one has ever claimed victory. For those who believe equivalence is the start and end of the discussion, how do you explain the fine qualities of the latest cell phone cameras with their very small sensors? (The artificial sauce isn't entirely responsible.) But the bottom line doesn't change - increased magnification of a capture involves complex trade-offs - but the end result of greater magnification always reduces image quality. The differences in sensor size are pretty marginal at normal viewing distances until you get up to at least 3x difference. I'm sure that was why Fujifilm skipped full frame - and focused on APSc and medium format.
You can see the difference, and the rendering of the smaller sensor is often readily apparent in the OOF areas. Most of modern lenses just make it worse with their busy backgrounds ("don't pay attention to that - look at how sharp that nose is! Forget the rest of the image, please). You don't see that with most MF images. It isn't really in the sharpness - but you really do see it in the rest of the image.
This topic has been debated endlessly, and the answer isn't simple. No one has ever claimed victory. For those who believe equivalence is the start and end of the discussion, how do you explain the fine qualities of the latest cell phone cameras with their very small sensors? (The artificial sauce isn't entirely responsible.) But the bottom line doesn't change - increased magnification of a capture involves complex trade-offs - but the end result of greater magnification always reduces image quality. The differences in sensor size are pretty marginal at normal viewing distances until you get up to at least 3x difference. I'm sure that was why Fujifilm skipped full frame - and focused on APSc and medium format.
You can see the difference, and the rendering of the smaller sensor is often readily apparent in the OOF areas. Most of modern lenses just make it worse with their busy backgrounds ("don't pay attention to that - look at how sharp that nose is! Forget the rest of the image, please). You don't see that with most MF images. It isn't really in the sharpness - but you really do see it in the rest of the image.
Assuming equal sensor technology, you will get very close. This is especially true with current sensors as recent noise improvements are miniscule at best.
Equivalence does not care about the exposure triangle. Equivalence has nothing to do with matching camera settings and everything to do with matching the final image.
Morris0
Forum Pro
You can view it the way you wish. Exposure is very simple 1/ISO at f16 on a sunny day is always the same.
Morris
Yes.
It is pretty simple:
The traditional exposure model is based on light per unit area, specifically so that it works across formats (at the risk of obscuring the magnitude of difference made by format size).
Equivalence is based on per-whole-image light gathering. It is not a system for exposure but a way of understanding those differences obscured by the standard exposure model.
Both are true. There's no victory to be had.
I don't believe equivalence is the start and end of the discussion, I'm not sure many people do. But it's more illuminating than stating that the standard exposure model is internally consistent in an attempt to shut discussion down.
With regards smartphones, the "artificial sauce" (specifically the combination of multiple exposures) is sufficient to account for the magnitude of discrepancy from what you'd expect a single shot, equivalent image to deliver.
Equivalence is just very basic physics and maths, and is remarkably robust, whether worked from first principles or directly tested.
Magnification is essentially a film-era way of expressing the same thing. The difference is that equivalence makes (slightly) clearer that the root cause is light (signal) not the magnification of the data. But they both lead you to the same conclusion, ultimately.
The differences are what the differences are. In bright areas of an image most formats can deliver 'good enough' but the differences come in where the transition from good to ok to disappointing happen. The 'tonality' that (44x33) medium format users love can be accounted for by the 2/3EV SNR benefit they can offer over a full-frame camera with the same base ISO. Likewise, the tonality benefit full-frame users claim over APS-C comes from the roughly 1 1/3EV benefit...
I'd personally agree with you that APS-C and full-frame, and full-frame and 44x33 MF are too close to offer big enough size/price/IQ differences for both to thrive alongside one another in the same system. But it's also true that full-frame is hotly contested and hard to break into, which is another good reason for Fujifilm to bracket it, regardless of the IQ arguments.
In the same way that knowing the F-number of a lens tells you nothing directly of its performance, knowing the equivalent F-number doesn't, either. But it gives a very, very good idea of what to expect in terms of depth-of-field, diffraction, noise/tonal quality, etc.
There is no battle to be had because equivalence is logically and demonstrably true.
It's fair enough to point out that it's not an exposure system, if someone seems confused, but the answer to the OP's question is yes. Saying the the standard exposure model works, or baselessly declaring 'the jury's out' or stating you don't find it useful isn't helpful to anyone.
If you don't find the concept useful, walk away, rather than spuriously trying to dead-end other people's discussion.
Richard - DPReview.com
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No, it isn't.
You don't have to, but you can. And the OP is explicitly asking about the situation where you do.
Bokeh is not a synonym for depth-of-field.
Yes, using an APS-C sensor is very much like only using an APS-C region of a larger sensor. Not sure how that helped.
And that's the point, isn't it? If someone is happy to think of a 24mm lens on APS-C as being equivalent to a 35mm lens on a hypothetical full-frame camera, why not let them understand the degree to which it is and isn't like that hypothetical lens?
The effective aperture diameter of in a wide-open 24mm F2.8 is 8.6mm. In the hypothetical 'equivalent' 35mm lens, that 8.6mm diameter would be F4.0. And consequently the images produced by this hypothetical camera, that's seeing the same scene from the same distance, through the same-sized hole will be much more comparable than the example you've set out.
The answer to the OP's question is "Yes."
Richard - DPReview.com
These noise levels look pretty similar to me:
Exposure doesn't determine the amount of noise in a photo; the total light used to make the image does.
Here's a link to a post from a few years ago when I used my X-T20 to make test photos representing equivalent photos made with full frame and micro four thirds formats: https://www.dpreview.com/forums/post/65018878
With all due respect Morris, the exposure triangle concept is fundamentally wrong. ISO does not determine exposure. Instead, it is determined by shutter speed, lens f-number, and scene luminance.
a_c_skinner
Forum Pro
Yes for field of view, beyond doubt.
The aperture question is less clear cut and that logic only really applies to your ability to control DoF with wide apertures. I'd also point out that one stop's reduction of depth of field isn't a huge amount.
The exposure doesn't change. The ability to use shutter speed to control movement is not changed because of this I think.
The aperture question is less clear cut and that logic only really applies to your ability to control DoF with wide apertures. I'd also point out that one stop's reduction of depth of field isn't a huge amount.
The exposure doesn't change. The ability to use shutter speed to control movement is not changed because of this I think.
It's just as provable / consistent.
This is false. It's not only applicable at wide apertures and, at the same shutter speed, cameras with equiv focal lengths and aperture will have the same amount of light hitting the sensor. Which results in highly comparable performance (given modern sensors perform very similarly).
That's a separate issue. Equivalence just tells you how big the difference is, not whether it matters.
No, but...
If two cameras see the world through the same sized hole for the same period of time, they have the same number of photons hit their sensors. You can choose whatever shutter speed you wish on either.
Richard - DPReview.com
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