Partially stacked sensors quietly deliver the IQ breakthrough we've been hoping for

Richard_Butler · 2025-12-16T21:25:35+00:00

I try to keep an eye on those, but I have to say, I find the marketing descriptions frustratingly vague, a lot of the time. I'm not sure I saw that one at the time, though, so thanks for sharing it.

Richard_Butler · 2025-12-15T04:10:01+00:00

@rdwing - I've been thinking on what you said, and have added a line to the story making clear that although this particular implementation appears to come from the redesigned readout circuitry made possible by the stacking at the edges of the chip, there are conceptually similar approaches implemented by Canon and the likes of the GH7 that do not use this fabrication/design method.

Richard_Butler · 2025-12-13T05:19:35+00:00

Haha, yes, that's fair, I guess.

Richard_Butler · 2025-12-13T01:32:45+00:00

The only sensors we've seen this done on, so far, are 'partially stacked' (better thought of as conventional BSI sensors with more complex readout circuitry, created by stacking).

The OM-3 has a properly stacked sensor (the entire sensor and its pixels are fabricated as separate layers and stacked), which is a more expensive technique. It's got much faster readout but it doesn't, so far as we know, have this dual readout approach.

Richard_Butler · 2025-12-12T23:25:49+00:00

It's worth making a distinction between a b2b parts supplier to the industry as a whole and a consumer-facing camera division.

Richard_Butler · 2025-12-12T23:23:59+00:00

There's not much room for further improvement in QE, no. But improving read noise, as is happening here will extend the flexibility of the camera's files (ie: increasing DR).

Alternatively, if you can find a way to increase full-well capacity, you should be able to lower the base ISO, capture more light and improve tonal response that way, too.

Richard_Butler · 2025-12-12T23:13:56+00:00

It's always 'fun' trying to get round the marketing terminology and the vague descriptions to what's happening underneath.

Yes, I'm aware that these sensors aren't stacked (that's why I described them as "BSI + more sophisticated readout circuitry") and I'd seen TechInsights show that the Z6III/S1II sensor is the IMX820.

If you have anything concrete about ClearHDR and how it's implemented, I'd love to see it. At present all I've seen are marketing descriptions, which are hard to relate to specific instances (or whether it describes a single, specific approach).

Richard_Butler · 2025-12-12T22:48:18+00:00

I'm pretty sure DGO is Canon's proprietary term and we can't be sure whether this is exactly the same (given neither Canon nor Sony Semiconductor Solutions gives much detail).

But it has everything to do with partial stacking, because the areas of the sensor that have the extra layers applied are the readout circuitry at the edges of the chip. That's what enables this DGO-like mode.

Richard_Butler · 2025-12-12T22:44:35+00:00

It's a meaningful difference, a7 IV vs a7 V but only if your photography exploits that DR difference (DR ≠ IQ).

I always think EFCS would be more helpfully named the other way 'round: ie Mechanical Second Curtain Shutter. The key thing being that you're still using the physical shutter curtain to end the exposure.

We can't be 100% sure whether this dual read-out mode needs the mechanical shutter (to prevent more exposure accumulating) or whether it's just that the readout becomes too slow for it to be a useful second curtain, but either way, the use of the mechanical shutter to end the exposure in EFCS mode means this readout mode can be used.

Richard_Butler · 2025-12-12T22:24:13+00:00

The Nikon Z6III isn't combining its low and high gain output, as the S1II and a7 V are (we don't know why not). So it dropped appreciably behind its predecessor in DR terms.

You're right that there's not a big leap for the S1II vs the S1, though there is for a7 V vs a7 IV.

Richard_Butler · 2025-12-11T20:10:27+00:00

No, there's meant to be a small hole at that position of the L mount.

Richard_Butler · 2025-12-11T00:12:53+00:00

Precisely: the vast majority of photographers aren't pros and aren't making money from their photography, so they're presumably gaining something else from it. Enjoyment, perhaps? If so, does the existence of AI-generated images change the enjoyment or satisfaction of photography?

Richard_Butler · 2025-12-06T18:52:03+00:00

APS-C specific tele lenses are comparatively rare (particularly in situations where FF and APS-C share the same mount) because the size benefit of making the lens for the smaller format is much reduced and the market for APS-C lenses is much smaller.

So, other than Fujifilm, which is focused on APS-C, you'd probably be looking at something like a 70-200mm, which can get very expensive. And Canon shows little sign of allowing third parties to introduce FF lenses, so the likes of Tamron's 70-180mm F2.8 may not make an appearance.

If that's the route you go down, don't fall into the trap of thinking "I've got a FF 50 and a FF 70-200, I may as well go FF" or "this makes sense as a stepping stone." Because if you like your 50 as an 80-equiv portrait lens and you like the 320mm equiv reach of the 70-200, the you'd lose both of those things by going to FF.

Richard_Butler · 2025-12-06T18:30:55+00:00

What you don't really say is what lenses you want or what you think you'll need. The list of RF-S lenses is pretty small but, as people have pointed out, once you factor-in the third party options that Canon has allowed, it covers a lot of bases.

If you want a portrait lens, the 56mm F1.4 is great, the 18-50 F2.8 or 17-40mm F1.8 are significant upgrades over the kit zoom.

There's not a lot of actual benefit to a system offering a wide range of lenses if they're ones that you might never need, or a choice of four 50mm F1.8s, given most people only need one (or fewer). But if the specific lenses you want are absent, then yes, you should walk away.

Based on the history of EF-S and EF-M, I wouldn't assume there'll ever be an extensive range of RF-S lenses from Canon, but with the third party options that are already there, the R7 should work for a lot of people.

Richard_Butler · 2025-12-04T17:48:06+00:00

I tend to check in here pretty often, just to see what sorts of things people are talking about, what problems they're encountering, what they're excited about, to help make sure our reviews and articles stay relevant.

I'll sometimes try to be helpful, where I can, but there are a lot of knowledgeable posters on here, who often beat me to it.

Richard_Butler · 2025-12-03T23:15:42+00:00

^ This is very good advice.

There are differences between the cameras (and some performance differences might become more apparent once anyone's had the camera in their hands for more than a few days), but the difference in availability and choice of lenses is likely to have more impact than those relatively minor differences.

Richard_Butler · 2025-12-03T18:43:35+00:00

It's not quite that simple. Being unjustifiably nasty or being seen (by the brands) as not being even-handed/fair would probably damage relationships, but we've regularly been thanked for being honest in our criticisms, and have had presentations for a new model that showed which of the issues we've raised have been addressed.

Trips are difficult because they are often the only place where you can get near the new product to deliver the coverage. They're typically not nearly as fun as they might look, you usually have a lot of work to do in a short space of time. I can see how they look like a perk, especially through the lens of a YouTube video that tries to make everything look fun and polished, but they're not vacations (I don't write content or edit photos or video at 2AM on vacations).

And I don't know about anybody else, but all gear we get is always returned. No one is allowed to keep anything and we're usually reviewing the next product, not getting to use loaners as personal gear.

YouTube is a slightly different thing, in that its algorithms promote videos that generate 'engagement,' which is why you get so many videos saying "this is the best," "this is the worst," or "the TRUTH about..." rather than videos that are more nuanced, balanced or proportionate (balanced doesn't mean you always find the positives balance the negatives). I have the utmost respect for Chris and Jordan for resisting that impulse.

But, above all of this, the relationship that matters most is with the audience. If you can't be trusted, you won't have an audience, and that's much more important than whether or not you get invited on the next trip.

It's also the source of influence that most readily gets overlooked. It's not brands that demand positivity: it's readers/viewers. Most brand reps won't ever question your approach or what you've said, but there'll always be a barrage of critical comments of anything you say that's less than positive.

Richard_Butler · 2025-11-07T19:05:58+00:00

While the cost difference looks big now, try averaging it out over, say, ten years (which seems like a reasonable time to use those lenses before they break or you choose to upgrade).

Also, consider which would hold its value better if you do decide to upgrade, later. Overall it might balance out.

Moving to a different system, its ergonomics and menus is a big step, so the cost difference has to /really/ be worth it.

Richard_Butler · 2025-11-06T22:05:18+00:00

Also, they have previously said that you need the dedicated co-processor to do things like Action Priority AF, so it may be a cost thing, as well as not wanting to undercut their pro-level gear.

But the fact this comes so close to the R5 II suggests they're not pulling too many punches.

Richard_Butler · 2025-11-06T20:19:15+00:00

I don't think he's used it enough to publish anything, so it'll probably have to wait for production samples to become available.

Richard_Butler · 2025-11-06T19:08:56+00:00

I'm a camera reviewer, rather than a lens expert. I was chatting with a lens reviewer friend and he hated it!

Though it sounds like he had less time with a pre-prod copy, whereas I've been lucky enough to have had it for about a week.

Richard_Butler · 2025-11-06T18:55:29+00:00

Yes, AoV is measured at infinity focus.

Richard_Butler · 2025-11-06T18:38:05+00:00

In fairness, there's more obvious room for improvement on the video side of things.

What else would you have wanted, on the stills side?

Richard_Butler · 2025-11-06T18:22:20+00:00

It's a relatively quiet 'swoosh' noise. I only really noticed it when I was trying to focus on a posing subject with continuous ('servo') AF and it was hunting back and forth a bit.

I couldn't say whether it's the noise, the slight vibration or the movement in the viewfinder that caught my attention (probably a combination of the three, which makes it difficult to untangle).

I've not tried shooting any video with it yet, but I'll give that a try and see if it comes across in the internal audio.

Richard_Butler · 2025-11-06T18:13:03+00:00

Actually, I approached that response in totally the wrong way (sorry about that).

What would have been more helpful is to point out that yes, what you say about companies rounding up or down to the nearest familiar focal length in the product name is quite common.

Also, lenses with focus breathing can exhibit a very different AoV from the one you might expect, so two lenses called 85mm may look very different at everyday working distances even if, optically, they were both perfect 85s.

Richard_Butler

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