RogerCooke: @RACHOTILKO: I found this article helpful http://www.cambridgeincolour.com/tutorials/digital-camera-sensor-size.htm
@ Beach Bum: Please mind your tone, or sign off.
I appreciate your (sort of) support, but look at the obstacles I've had to face here.
I'm battling a troll and 10 people out to prove me wrong (plus fatigue). I dare anyone to main a perfectly civil tone dealing with this.
Having knowledge is often a curse rather than a blessing, honestly. I wish I could half-ass my way through life like most people. But it isn't to be unfortunately. :(
Rachotilko: To DPR team:
to reduce the confusion, would you not consider an article about the f-number equivalence ?
The question "does the need to apply f-number equvalence apply to DOF calculation only or to shutter speed calculation as well" has been hotly debated here for quite a long time.
Some basic lesson in photooptics would silence this, I hope.
I never claimed that there weren't many other factors affecting a camera's performance. That doesn't mean that the factors I mentioned aren't very important.
I want to point out that I was sort of pulled into this by another guy trying to spread misinformation. When I encounter that, I'm going to try to clear it up, especially when that misinformation tells people that a smaller sensor camera is going to perform just as well as a bigger sensor.
Absent the misinformation, I wouldn't have ever said anything.
That's not really very useful. If you have nothing to add (which seems to be the case), then just sit back and read and try to learn something.
If you have something useful to add, then by all means, do it.
Of course, I never meant this to be an exact and irrefutable thing, just a general guideline. You'd have to be crazy to think you can learn everything about a camera just by doing some math and not seeing real world results.
But it doesn't hurt to do these types of comparisons before you do your real world comparisons.
Also, regarding small sensor cameras and their "clean" output, aside from possibly greater sensor efficiency, one must consider the heavy NR most of these apply.
This becomes obvious when you compare the level of detail between a 12MP 1/2.3" sensor and a 12MP M43 sensor. There's really no comparison as any M43 camera will blow the smaller sensor away for level of detail. From my experience, you have to reduce a 12MP image from a 1/2.3" sensor down to 3 to 5MP for it to appear equally sharp to a large sensor image (when viewed at 100%).
A lot of this probably has to do with the heavy-handed NR that must be applied to keep it "clean".
You see what I'm saying about Rachotilko being a troll. Look at all the detail I've gone into.
Has he explained his point of view at all? In fact, no.
His only goal in life appears to be to provoke people. And there's no need to harp on it because, if you don't see it now, you'll see it soon enough.
This guy is nothing but trouble. :(
In fact, you're wrong. But, if you want to continue this discussion (with me), then move it to to the topic Rachotilko started. I'm not going to check everything.
Briefly, here's why you're wrong. The exposure is the same at the same F-number across all formats, but the relevant measure is the total light not the exposure, when the goal is to create equivalent pictures.
Regarding this statement, "A full frame camera doesn't just miraculously catch 2x the amount of light as a crop sensor despite being twice the size", I'm afraid I'm going to need a translation to English on that.
I'm not sure of English is your primary language or not.
They're probably not exactly equally efficient per unit, but they're probably close enough for an accurate comparison.
They're both Sony sensors manufactured in the same year, so it wouldn't be a stretch to assume similar efficiencies per unit area. And it would have to be pretty far off for my comparison to be invalid.
p.s. No need for sarcasm. You don't know me, and you don't know what I know.
The P7700 has a max relative aperture of F2 (from my recollection). So, with both the RX100 and P7700 at their widest angle, the RX100 is actually taking in 4X as much light (a two stop advantage), assuming equivalent shutter speeds.
What's clear is that at the same shutter speed, both at their widest angle, the RX100 has a distinct and large advantage.
If you went only by the relative apertures at widest angle (F1.8 vs F2), you'd only think the RX100 has 1/3 stop advantage. But doing this, you've neglected the 1.6 stop advantage that the RX100 has at any F-number.
Now, how do you get the same shutter speed on the RX100 and P7700 when the RX100 has a 2 stop advantage in total light intake. My argument was that the only way this could happen would be that ISO100 on the P7700 is actually a higher ISO than on the RX100.
In that way, when you use the same shutter speed at widest angle on both cameras, they're not equivalent images. The P7700 will by necessity be noiser.
Out of space.
In fact I wasn't wrong about anything I said. Online, it's very difficult to know who's actually on the ball and who's blowing smoke.
The thing that doesn't come across is the depth of my knowledge on this topic. For one thing, this topic is about as basic as it gets regarding the comparisons I do between cameras. One of these days, I'm going to publish some of the documents I've written on the topic.
Now, here's why I wasn't wrong. To get equivalent images across formats, it's a well-established fact that you have to have the same total light (not the same F-number), assuming equal sensor efficiencies. I knew this well before the widely referenced online article on equivalence.
Let's use the RX100 and P7700. They both use similar quality Sony sensors, but the RX100 has 3X the sensor area. Let's assume that the RX100 has an aperture of F1.8. In order for both cameras to take in the same total light, the P7700 has to have an aperture of about F1.
To be continued...
The problem with Rachotilko is that he's being deliberately provocative. He got into a debate with another guy called noirdesir. Instead of continuing the debate where it started, he started another topic.
Then when he got into a debate with me, he started yet another topic. Not for one second do I believe he's actually asking for assistance. He's trying to provoke people, and I'm sorry if you can't see that.
You base your judgements on a mistakend notion that sensor size is to be taken into account when calculating the lens speed.
Consider situation when you're using XZ-2 @ISO800, f2.4, l=100mm eq. Taking the same scene with RX100 would require you to use IS3200.
That's a lot of a difference, don't you think ?
I'm getting tired of this. Your last post really makes no sense. It's not that I don't understand it. It's just that it literally has nothing to do with what we were discussing.
Your first post was unequivocally wrong however. You do in fact have to factor in the sensor size. It's the total light that hits the sensor, not the F-number, that creates equivalent pictures between formats.
Nothing else that's written is going to change that fact.
I've noticed a similar phenomenon myself. And my only explanation is that the manufacturers of small sensor cameras are tweaking the ISO values on these cameras so that you can use similar shutter speeds on the small sensor cameras as you can on the larger sensor cameras.
This is just my opinion, so I'd like some feedback from others, but I see no other way for it to be. It's the total light that falls on the sensor that creates comparable pictures among different formats, not the exposure (i.e. F-number).
So, IMO, ISO 100 on a small sensor camera is probably really a higher ISO value than ISO 100 on a full frame, although I'm just speculating.
I haven't seen noirdesir's post you're replying to, but just reading what you've written, it's clear you're dead wrong.
In order to compare cameras, you have to factor in both the sensor size and the F-number, to know which camera is faster at a given focal length.
Since the RX100 has 3x the sensor area of the XZ-2, it always has a 1.6 stop advantage at any F-number. So, if both are at F2.8, the RX100 is actually 1.6 stops faster because of the larger sensor.
This is what is known as equivalence.
xiod_crlx: FZ200 has typical small sensor ultra-zoom picture (e.g. rubbish, just for people buying this mega-ultra-10000x-zooms) .
It is not clear why it is in the list but no *Nikon P7700* or *Samsung EX2* ? No Fuji? Excellent new Sigma DPs???
1/1.7" sensor cameras like the P7700 have literally less than 50% (actually closer to 42%) greater sensor area than 1/2.3" sensors like the FZ200.
The difference is quite tiny, so I fail to understand people who think that 1/2.3" sensors like the FZ200 have "rubbish" image quality, while cameras like the P7700 come up smelling like a rose.
That kind of thought process is sort of "rubbish" IMO.
By contrast, a camera like the Sony RX100 has 3X the sensor area of 1/1.7" cameras like the P7700. Now that's a big difference.
So, IMO, cameras with 1/2.3" sensors have a lot of use because they provide a lot of zoom in a small package, and their video quality is actually sometimes better than the bigger sensor cameras.
If anything, it's 1/1.7" cameras like the P7700 that should disappear, to be replaced by 1" sensor cameras, like the RX100. I don't see the use of 1/1.7" cameras, as there's little to distinguish them from the 1/2.3" cameras, except for their lack of zoom. :)
keeponkeepingon: The ZS20 is sticking out in this collection like a sore thumb.
It's really really hard to believe that one of the "five best" compact zoom cameras in existance has "Average image quality" and only earns 75% on your own published review (a "C" in grade school).
I guess no one cares about IQ these days, not even dpreview.....
One could argue the same thing about most peoples' obsession with minutia regarding still images on this forum. Let's face facts, most of the things that people are arguing about amount to little more than minutia.
My point was that the difference in video between the Panasonic ZS20 and the Canon SX260 is actually far greater than the difference in stills, which is pretty small.
1080/60p has far more utility than the lower frame rates, as I'll explain later. But, more importantly, it's something that both Panny and Sony use to differentiate their cameras with high end video capability. IOW, it's not as much the actual frame rate as the fact that 1080/60p is something, that as of 2012, Panny only reserves for their high end video capable still cameras and camcorders.
Now, regarding the actual utility of 1080/60p. Simply stated, it provides smoother, more natural and lifelike motion than 30p or 60i. It's usually sharper than lower frame rates and it allows for slow motion.
JRApprentice: In relation to the Panasonic ZS20 you state
" Image quality is decent, but not outstanding. If you'd prefer better images, with fewer bells and whistles, the ZS20's 'younger brother' the ZS15, is worth a look. "
What on earth is a camera with an inferior image quality to its "younger brother" doing in a recommended list of cameras?? Or have we got to the state where "bells and whistles" matter more than IQ? I bought the ZS15 because it has the same, much praised, sensor as the FZ150 and the IQ of the ZS20 was known to be rubbish.
Come on Dpreview, you can do better than this.
Revenant, as I keep reminding people, the world is a different place than it was 10 years ago. Unfortunately, the mentality on this forum is stuck in the past decade, something that needs to be corrected.
Between video and stills, if one were to become obsolete a decade or two from now, it sure wouldn't be video. Once 4K and 8K video come around, do you think the average consumer is going to be content just taking a single snapshot?
The whole point of a camera in 2012 is not just taking pictures. With video quality better than most dedicated camcorders, people could easily buy the ZS20 just as a video camera and still have gotten a bargain.
My suggestion to most of you people would be to actually do some studying beyond your own little world.
The ZS20 is really a far better all around camera than anything Canon is even capable of putting out. I've put it to great use for videos and stills.
Absolute, unequivocal gibberish.
To get this kind of video quality in a dedicated camcorder, you would easily pay twice as much.
To keep things in perspective, even to this day, neither Canon nor Nikon (nor Olympus, Fuji, etc.) even offer 1080/60p on any camera (or camcorder).
To get video this sharp on any Canon model would cost at least $500, but you wouldn't even get the frame rate or autofocus capability, two things that Canon has yet to master at any price range.
This isn't a video site, you may say. In fact, it can be anything we want it to be, and this is something I'm going to emphasize in the future, as still cameras are going to be considered video cameras as well in the future.
The fact that your only understanding has to do with one aspect of the camera, while it's incredibly common here, is still a failing on your part.
So, do some studying. The ZS20 is the best bargain on this list.
leno, I agree and disagree.
But something you've failed to understand from my post is that the ZS20 DOES in fact have better image quality than the ZS15.
In 2012, there are two relevant types of image quality, stills and video. This is a distinction I made in my post, but you failed to make in yours.
This is a trend in DPReview that's eventually going to have to change as cameras become more all-in-one tools.
My point was that the ZS20's advantage in video IQ over the ZS15 is greater than the ZS15's advantage in stills IQ over the ZS20.
Aside from that, if I had a choice between a 5x camera with a 1/2.3" sensor with a very good stills IQ for its class (which by definition will never compete with a larger sensor camera) and a 20x zoom with a slightly lower stills IQ, I would take the 20x camera. And here's why.
A 1/2.3" sensor is never going to provide stellar stills quality. In this class of camera the greater zoom is more useful than a tiny increase in stills IQ.
attomole: Quoting Barney on the full review of the FZ200, leave me to believe DPR have either made a categorical error with its inclusion here , or its deliberately provocative choice.
By Barney Britton (4 days ago)It's not just about IQ. A big part of the reason why the FZ200 got such a good score (and bear in mind that scoring is relative to product category, and the P7700 is in a different one) is that it has an excellent lens, is nice and quick, handles really well, and offers Raw mode.
"Provocative" in what way?
You must be literally the hundredth guy here who is confused about terminology that, instead of actually looking up the definition of "compact camera", has to come here and literally pollute this topic with misinformation.
For the hundredth time, the FZ200 is as much of a compact as the ZS20. The term has nothing to do with the actual physical size of the camera, but with the fact that it's a fixed lens, small sensor camera.
Even Panasonic, on their site, classifies it as a compact. And I fail to understand why this is so difficult for some people to comprehend.
The FZ200 in fact has the best lens of any bridge camera to date. And, bridge cameras being considered compacts, it's inclusion is entirely appropriate.
Here are some other facts about this camera. It has some of the best video quality of any stills camera on the market today. It has among the fastest autofocus and speediest operation of any bridge camera.
Sothoth: This is a horrible review. A $249-649 price range? All shoot RAW but one? The FZ200 is a "compact?" Where is the LX7, S100, and a few others? Where are the image samples? I think this is a waste.
Actually, I think this round-up is excellent, and I was one of the first people to say so when it was first published a few days ago. If you go back and read my early posts, I explain why.
I also explain why I had to take a few days off from this forum after all the incessant and unrelenting whining over the FZ200 not being a compact (when it is in fact classified as a compact).
To summarize, I think this round-up is spot on.
I bought the ZS20 several months ago. And, guess what, at the time, I fully knew of the supposed image quality advantage of the ZS15 when I bought it. If I had it to do over again, I would choose the ZS20 any day of the week over the ZS15. And here's why.
The problem with this forum has always been a fixation on one aspect of the camera to the exclusion of all else. The ZS20 actually has as good or better video quality than any of my dedicated camcorders. It's 1080/60p video is as sharp as any single sensor camera on the market today.
The ZS15 only has 1080/60i, and it's nowhere near as good. The ZS20 has a longer reach than the ZS15 and probably a better LCD as well.
So, the ZS15 provides a slight advantage in still image quality. This isn't the be all and end all of what makes a good camera. The ZS20 is very competent with outdoor stills. The ZS15's advantage is just that, slight. And the ZS20 is the better overall performer.
The ZS15 is a very nice camera as well, BTW.