Is the Canon EOS R7 the next camera to be announced? [CR2]

[Jethro]

Neuro, I've been an occasional observer of your interactions with forum members (including Unfocused), for some time. I largely agree (to the limits of my technical and practical understanding) with a lot of what you are saying. Part of the reason I'm here is to learn - and I tend to want detail and precision. I think a lot of the issue comes down to the tone of what you're saying.

I think it's over the top to describe (as an example from your last post) Unfocused as making deliberate 'false statements and misinformation'. Your view is that what he is saying is wrong (and that you've already refuted it factually) and yet he keeps repeating / defending it - but I don't think Unfocused is deliberately trying to misinform people. He's putting a view which is much less technically focused than what you are (eg on the fraught Equivalence issue). Yes, there are technical definitions for some of these terms and concepts. And I'm interested in them in that context. But many of us in the Forum have more limited focus, and are (at least sometimes) using technical terms in a more vernacular sense. I think it's over the top to use pejorative language (and tone) in reply to these types of comments. I'm not saying that shouldn't be done to a particular class of participant who is here deliberately to spread misinformation. But there are (in my view) pretty clear delineations between that type of poster and a longterm contributor like Unfocused.

I really want to keep as many people as possible contributing regularly to the forum. And I think if the 'heat' of replies can be turned down, it will make it a more pleasant place for everyone. If the same technical disagreements arise - is an answer to simply include a link back to summaries (and there have been detailed ones posted) in the past? And then move on?

I know this is all sounding awfully like 'can't we all play nicely and get along', and I apologise for that - but tolerance and forbearance from all sides would be appreciated.

 

[privatebydesign]

Personally I am deeply concerned that irrefutably false information is repeated by people that know better time and time again.

Would anybody take seriously a poster that, when talking about exposure, says something like ‘I don’t think aperture or iso is relevant or even a part of the exposure question, oh and I don’t want to get drawn into a conversation about it’. Yet to the truly uninitiated looking for information that incorrect post has as much prominence as the truth particularly when that post is made by a long running well respected member. Equivalence is no more opinion than exposure.

You can work a camera without understanding exposure, indeed many artistic people have zero interest in any of that yet take fantastic photos, and that is fine. You can be a knowledgable pro and never consider or grasp the actual application of ‘equivalence’ and again that is fine. Indeed it seems to be the norm!

But if you do want to understand how to take a photo with identical image characteristics with your M50 and R5 there is a set in stone mathematically derived formula that is incredibly simple to learn.

Equivalence dictates you apply a factor, everybody calls it a crop factor, to focal length, and aperture, and iso. A crop factor can be a positive or negative value depending on if you are going up or down in sensor size. Cropping is exactly the same as using a smaller sensor. Ergo, if you crop all else being equal you change DoF. All else being equal includes, by definition, the same sized output, not scaled output.

Depth of field relies on only two factors after you determine what is ‘acceptable focus’. The size of the lens pupil. The size of the subject as you are looking at the image output. THAT IS IT.

Everything else in a DoF calculator is being used to determine those two numbers. Aperture, focal length, subject distance, sensor size etc etc are only relevant in determining the size of the lens pupil (not aperture) and the size of the subject as you are looking at it.

I draw a line when knowledgable people deliberately confuse or misstate the simple facts for seemingly no reason whatsoever. We all make mistakes, but continuing to push blatantly false ideas even when people have taken considerable time to explain the subject to you is either fraudulent, maleficent, or stupid.

If you don’t want to learn something that is fine, just don’t confuse the issue by trying to talk about exposure as a concept in terms of shutter speed alone, or equivalence in terms of focal length/fov/aov/afov alone. That belittles everybody and does no good.

 

[Sporgon]

Personally I am deeply concerned that irrefutably false information is repeated by people that know better time and time again.

If you don’t want to learn something that is fine, just don’t confuse the issue by trying to talk about exposure as a concept in terms of shutter speed alone, or equivalence in terms of focal length/fov/aov/afov alone. That belittles everybody and does no good.

Hey Private ! Can we talk about perspective next ?

 

[privatebydesign]

Hey Private ! Can we talk about perspective next ?

Please!

 

[Lee Jay]

The values that TDP reports for DLA are, as Bryan puts it, "The aperture where diffraction begins to visibly negatively affect image sharpness at the pixel level."

Diffraction always affects an image. It's always present and it's always decreasing MTF, regardless of aperture. So, if that's the definition they are using, the answer is always the same - f/0. If it's "visibly" then it's observer-dependent and you're putting human perception, judgement and preferences into the equation.

I prefer this definition, which is where MTF drops to zero:

Spatial cutoff frequency - Wikipedia

en.wikipedia.org

Spatial cutoff (line pairs per mm) = 1/(Nω)

Most people prefer the Rayleigh limit, which is where MTF drops to 9%:
Rayleigh limit (line pairs per mm) = 1/(1.22 Nω)

Understanding resolution and MTF

"How is MTF related to lines per millimeter resolution? The old resolution measurement— distinguishable lp/mm— corresponds roughly to spatial frequencies where MTF is between 5% and 2% (0.05 to 0.02). This number varies with the observer, most of whom stretch it as far as they can. An MTF of 9% is implied in the definition of the Rayleigh diffraction limit.

Perceived image sharpness (as distinguished from traditional lp/mm resolution) is closely related to the spatial frequency where MTF is 50% (0.5)— where contrast has dropped by half."

It seems your references use something more like the above definition of perceived image sharpness to mean "diffraction limited". To me, and to the entire astro community, "diffraction limited" means where you can't get any more resolving power, not where sharpness starts to visibly degrade.

 

[unfocused]

@unfocused do you feel bullied..

Do I personally feel bullied by you? No. I am used to it and it doesn't bother or deter me in the least. Do I find your constant bullying of others offensive? Yes.

On the previous subject, it really comes down to different perspectives.

My training is in journalism. I have a natural inclination to take subjects and try to boil them down to the essential and easiest to understand practical application. I consider many of the details to be unnecessarily confusing and superfluous. You come from a technical background. You live or die by the details and each and every detail is important to you. In short, you are a trees guy and I am a forest guy.

The truth is that I have an unfair advantage in these discussions. I can readily admit the validity of your statements, which I do, but at the same time I'm free to dismiss them as not particularly important in the general application of the concepts. On the other hand, since every detail is important to you, you get upset when I gloss over some of the finer points and become convinced that I am either ignorant of those points or purposely deceptive. Neither is the case, I just have a different goal in mind.

You feel that my generalizations are detrimental to people understanding certain concepts. I feel your excessively detailed and, I would say, rigid interpretations are detrimental to the actual practice of those concepts. We are probably both right and both wrong to a certain extent.

What is not debatable though is that these topics have already been discussed time and time again on this forum. Anyone who has the tiniest bit of interest in these topics can easily read through past debates and draw their own conclusions. There is really no reason to further clog the forum with repeated discussions. I am guilty of getting lured into these discussions and I should know better.

I do think you would be wise to follow the advice that have been offered to you in regards to forum etiquette. However, I don't hold out a lot of hope that that will occur. Over the years you have carefully cultivated a forum personality that I and many others find offensive. I have no idea why you take such pride in being thought of as...well.. as a world-class jerk. But, that's how you have defined yourself. As the saying goes, it's not a bug, it's a feature. I doubt that you have the capacity or desire to change.

 

[neuroanatomist]

I think it's over the top to describe (as an example from your last post) Unfocused as making deliberate 'false statements and misinformation'. Your view is that what he is saying is wrong (and that you've already refuted it factually) and yet he keeps repeating / defending it - but I don't think Unfocused is deliberately trying to misinform people. He's putting a view which is much less technically focused than what you are (eg on the fraught Equivalence issue).

You can hold the opinion that my replies are ‘over the top’. But false statements and misinformation about objective, factual matters are just that. False.

If I posted that 2+2=3 or that hot air balloons rise into the air because they are not subject to gravity, would it be ‘your view’ that what I’m saying was wrong? If several people replied with factual evidence that the sum of 2 and 2 is 4 and that Earth’s gravity acts on all mass, and I kept posting that 2+2=3 or that gravity confuses some people so I’m just going discuss hot air, would it be ok to excuse such repeated statements as ‘less technically focused’?

We’re not talking about subjective topics. If he or anyone posts that APS-C is better than FF or that a 16-35mm lens is great for sports, I’d happily debate those viewpoints…but there’s no right or wrong involved. We are talking about objective, factual errors restated many times despite unequivocal contradictory evidence.

Let’s take a recent example from this thread:

Depth of field is not sensor dependent.

Depth of field resides solely within the lens and distance to subject.

That is patently false. A casual perusal of the Wikipedia page on DoF is all that’s needed. A white paper from Zeiss states it succinctly, “Reducing the size of the film format therefore reduces the depth of field by the crop factor.”

Now, let’s look back to this post from 2017, where after @privatebydesign and I explained the exact same concept in detail, @unfocused finally replied with, “Oh, I get it now.” Since then, he has posted that sensor size does not affect DoF on several occasions. What is that, if not deliberately trying to misinform people? I suppose the only viable alternative explanations are that he's not sufficiently intelligent to understand these concepts, or he has some sort of learning disability, and I don't think either is the case.

@Jethro and @Czardoom, you are welcome to defend anyone you choose, and you have the right to condone the behavior of someone who deliberately posts false information. Personally, I won't tolerate it.

 

[neuroanatomist]

Do I personally feel bullied by you? No.

Good, I am glad. That is absolutely not my intent.

On the previous subject, it really comes down to different perspectives.

My training is in journalism. I have a natural inclination to take subjects and try to boil them down to the essential and easiest to understand practical application.

Simplifying a complicated concept is different than making false statements. The former is an attempt to help people understand a concept. The latter is outright lying. Somehow I doubt your training in journalism included encouraging you to make false statements.

Stating that sensor size does not affect DoF is false. Period. It's not a different perspective. It's not a simplification. It's false. If you know that you're making a false statement and you make it anyway, that's a willful lie. I wonder what those who trained you in journalism would think of one of their former students lying to the public. From what I've seen, journalists take a pretty dim view of that.

 

[AlanF]

My training is in journalism...

The truth is that I have an unfair advantage in these discussions.

We have a Prime Minister who is trained in journalism. He has an interesting relationship with the truth.

Boris Johnson: What is the PM's relationship with the truth?

The PM's attitude to facts is based not on what's real, but what he wants there and then, say sources.

www.bbc.co.uk

No wonder deceit is dragging Boris Johnson under – he’s not even a good liar | Simon Jenkins

The prime minister is belatedly learning that a few jokes cannot distract from a catalogue of deceit, says Guardian columnist Simon Jenkins

www.theguardian.com

 

[neuroanatomist]

Hey Private ! Can we talk about perspective next ?

We are! Some people have the perspective that lying is just telling the truth from a different point of view.

Oh wait, you meant this kind of perspective:


Mmmmmm, beer!

 

[Blue Zurich]

This is an Eckhart Tolle moment (needed) if I ever saw one.

 

[lote82]

On the previous subject, it really comes down to different perspectives.

YES!
You two are like fact vs. relevance.

It is true that different sensor sizes will cause different dof!

But for me (and maybe also unfocused) it has zero practical relevance!
Why? Because I don't care about sensor sizes. I only care about images.

To give an example:
If you take a photo at same distance, with same (FF)lens, same focal length and same aperture, one with APS-C and one with FF camera, you'll get two different images. But if you crop down FF image to APS-C size to get comparable images, dof (of the cropped image!) will be the same as the APS-C image.

Distance, focal length and aperture are the only factors which do really matter regarding to dof. Because these are the only factors you can influence (at least if you only have ONE camera with you). You can walk (distance) and/or change lens (focal length) and/or change aperture, but it's impossible to change the size of the sensor in your camera. So again: Sensor size has impact on dof, but it doesn't matter because you just can't influence it in any way!

No need to freak out about scientific terms (my English is too bad to know a lot of them). In the end it only matters how you can practically use theories for your photography. I'm quite confident unfocused knows how to deal with dof even if he's not always 100% precise describing it.

 

[unfocused]

...Cropping is exactly the same as using a smaller sensor. Ergo, if you crop all else being equal you change DoF. All else being equal includes, by definition, the same sized output, not scaled output.

Depth of field relies on only two factors after you determine what is ‘acceptable focus’. The size of the lens pupil. The size of the subject as you are looking at the image output. THAT IS IT.

Everything else in a DoF calculator is being used to determine those two numbers. Aperture, focal length, subject distance, sensor size etc etc are only relevant in determining the size of the lens pupil (not aperture) and the size of the subject as you are looking at it.

As you frequently do, you have made valid points and offered some excellent technical details. I actually have a few questions.

I'm not sure I understand this statement: "if you crop all else being equal you change DoF."

When I first read this it sounded like you were saying that If I take a 3000 x 2000 px. image in photoshop and crop out a 1000 x 500 section of that image that the depth of field magically changes. I can understand how the perception would change if you change the viewing distance or enlarge the image, but why would the depth of field change simply by cropping an image? Certainly that image is already set in stone, so to speak, and cropping alone could not change the depth of field.

After re-reading what you wrote, I now interpret your statement to mean that cropping a full frame image down to the same dimensions as an APS-C image will produce the exact same image and depth of field. (all other factors being equal). That, by the way, is exactly what I have said in this discussion. But, is it really correct to say that you are changing the depth of field? Isn't the depth of field for that cropped portion of the image exactly the same as it was before the cropping? How could the depth of field possibly be changed by simply throwing away pixels?

I'm also interested in your other statement:

"Depth of field relies on only two factors after you determine what is ‘acceptable focus’. The size of the lens pupil. The size of the subject as you are looking at the image output. THAT IS IT."

I certainly don't disagree with your statement as a scientific fact. But from a practical matter, how does this differ from saying (as I did) that depth of field is determined by aperture, focal length and distance to subject? Hardly anyone knows the size of the lens pupil of their lenses. You probably do, but most people don't. So why is it not acceptable shorthand to use the aperture and the focal length? Two things that people do know.

Similarly, why is "distance to subject" not an acceptable shorthand for "size of the subject as you are looking at the image output." Here, I understand that we may be talking about different things when we refer to "subject." I am thinking about the typical situation where one is taking a picture of another person. Generally speaking, how close the photographer is to that person (coupled of course, with the focal length of the lens) will determine the size of the subject as you are looking at the image output.

In other words, if I am taking a picture of my wife with a 200mm lens on a full frame camera, I have a general idea of how much of the frame I want to fill with her face and how much I want of the background to show. I adjust my distance from subject to roughly correspond to the size of the subject that I will be looking at in the image output. At the same time, if I want to decrease the depth of field for the background, I may adjust the distance between her and the background. Again, I'd like to know why this is not acceptable shorthand for your more precise technical definition.

 

[koenkooi]

[..]When I first read this it sounded like you were saying that If I take a 3000 x 2000 px. image in photoshop and crop out a 1000 x 500 section of that image that the depth of field magically changes. I can understand how the perception would change if you change the viewing distance or enlarge the image, but why would the depth of field change simply by cropping an image? Certainly that image is already set in stone, so to speak, and cropping alone could not change the depth of field.[..]

I think 'cropping' in this instance means cropping the image and then enlarging that crop to be the same output size, e.g. print it to 8x12". And viewing it at the same distance.

If by cropping you mean 'take a pair of scissors and cut the portion you want out of the larger picture' and you don't change the viewing distance, then: no, DoF didn't change. But I don't think that's what being meant when people use 'crop' in this context.

I'm still unsure if I fully grasp how this all works, so I'll gladly be corrected For most of my macro shots, I viewed them at 100% on my computer screen, regardless of which camera was used (APS-H, APS-C, FF or phone), This workflow made it very hard for me to reconcile what people were saying here and what I was seeing on my screen. I think a similar disconnect is happening when neuro and dalantech have a discussion about DoF and the MP-E65mm. But like I said, I'm unsure I fully understand this, so it's an even bigger stretch to say I understand what other people actually mean when talking about this

 

[Lee Jay]

I think 'cropping' in this instance means cropping the image and then enlarging that crop to be the same output size, e.g. print it to 8x12". And viewing it at the same distance.

That's correct.

We always sort of implicitly assume that final images will be viewed at the same final size, regardless of how they were collected or processed. This seems reasonable. Do you view an image differently depending on how you cropped it in post? Do you print it a different size when you change the size of the crop? Probably not.

So, yes, it's the enlargement or viewing condition that changes the DOF when you crop, but that is done *because* you cropped - to keep the final image the same size and viewed the same way.

 

[neuroanatomist]

When I first read this it sounded like you were saying that If I take a 3000 x 2000 px. image in photoshop and crop out a 1000 x 500 section of that image that the depth of field magically changes.

Yes, if you take a 3000 x 2000 px. image in photoshop and crop out a 1000 x 500 section of that image, then the depth of field for that section of the image changes. It's not magic, it's physics.

But, is it really correct to say that you are changing the depth of field? Isn't the depth of field for that cropped portion of the image exactly the same as it was before the cropping? How could the depth of field possibly be changed by simply throwing away pixels?

Yes, it is really correct and no, the depth of field for that cropped portion of the image is not the same as it was before the cropping. Again, physics.

Similarly, why is "distance to subject" not an acceptable shorthand for "size of the subject as you are looking at the image output."

Because the distance to the subject is only one factor in determining the size of the subject as you are looking at the image output. Enlargement is another factor. That means the degree of magnification required to go from the size subject as it is projected onto the sensor to the size of the subject as it appears in the output.

The assumption here is that the output is fixed, i.e. you are comparing the two images (or the full image with a section cropped from it) at the same output size and viewing distance. That assumption is made because it enables the comparison. Slightly different numbers may make it easier to discuss, I suggest a 3000x2000 pixel image and a 1500x1000 crop, e.g. 1/4 of the original image. The idea is you are comparing both of them as filling the screen of your display, or if you prefer printed as an 8x12" image. The 1500x1000 crop has to be enlarged to a greater extent than the original image to fill the display or the 12x8" print. That greater magnification results in a shallower DoF. That is how sensor size affects DoF directly – a smaller sensor needs a greater amount enlargement to produce the same final output size.

I'm sure your response will be along the lines of what @koenkooi just posted, that you want to compare the 3000x2000 pixel image printed at 8x12" with the 1500x1000 pixel image printed at 4x6". In that case, the degree of enlargement is the same so the DoF doesn't change. But that's like a stopped analog clock being right twice a day – a contrived scenario to make something correct only in a very specific set of circumstances.

If you like, you could print all your FF images at 36x24" and all your APS-C images at 22x15" and then for you, sensor size would not affect DoF in your prints. Not very realistic, is it? In the same way, you can compare the 3000x2000 pixel image viewed on a 49" display at arms length with the cropped out 1500x1000 section of that image viewed on an iPhone from across a football stadium. But that's not really a valid comparison, is it?

The point is that enlargement plays a role in determining DoF.

But the real issue here is that this has all been explained to you before. Many times. Yet you still persist in posting the same false statements and misinformation. And as long as you continue posting misinformation on this forum, people will continue countering your lies with facts.

 

[neuroanatomist]

It seems your references use something more like the above definition of perceived image sharpness to mean "diffraction limited". To me, and to the entire astro community, "diffraction limited" means where you can't get any more resolving power, not where sharpness starts to visibly degrade.

Agreed. My original point still stands, though. Given that TDP defines DLA as the aperture at which diffraction begins to noticeably soften the image, and posts that the DLA of the 90D/M6II is f/5.2, that is not wrong. There's a semantic issue at play here, too:

lim·it, /ˈlimit/ noun​

1. a point or level beyond which something does not or may not extend or pass.​

2. a restriction on the size or amount of something permissible or possible.​

You're using the first definition of the word 'limited', the references above are using the second.

Although I don't do a significant amount of astrophotography, 'diffraction limited' also has a different connotation in the microscopy community that is similar to your point about astro. We can talk about Abbe limits, Rayleigh limits and Sparrow limits on microscopic resolution if you like. One nice benefit of fluorescence microscopy is that we can more accurately define those limits because we are working with a single wavelength or at least a very narrow band. There are also newer techniques that enable getting around the diffraction limit, collectively termed super-resolution microscopy, that allow optical resolution down to ~250 nm with visible light, which is higher frequency than visible light.

 

[privatebydesign]

I think 'cropping' in this instance means cropping the image and then enlarging that crop to be the same output size, e.g. print it to 8x12". And viewing it at the same distance.

If by cropping you mean 'take a pair of scissors and cut the portion you want out of the larger picture' and you don't change the viewing distance, then: no, DoF didn't change. But I don't think that's what being meant when people use 'crop' in this context.

I'm still unsure if I fully grasp how this all works, so I'll gladly be corrected For most of my macro shots, I viewed them at 100% on my computer screen, regardless of which camera was used (APS-H, APS-C, FF or phone), This workflow made it very hard for me to reconcile what people were saying here and what I was seeing on my screen. I think a similar disconnect is happening when neuro and dalantech have a discussion about DoF and the MP-E65mm. But like I said, I'm unsure I fully understand this, so it's an even bigger stretch to say I understand what other people actually mean when talking about this

You are correct, in that instance you are not looking at equivalent (same sized) images. There has to be a baseline in any comparison, comparing a large print to a small print is not a fair or direct comparison so is not what people who bang on about equivalence are referring to.

 

[Hector1970]

We have a Prime Minister who is trained in journalism. He has an interesting relationship with the truth.

Boris Johnson: What is the PM's relationship with the truth?

The PM's attitude to facts is based not on what's real, but what he wants there and then, say sources.

www.bbc.co.uk

No wonder deceit is dragging Boris Johnson under – he’s not even a good liar | Simon Jenkins

The prime minister is belatedly learning that a few jokes cannot distract from a catalogue of deceit, says Guardian columnist Simon Jenkins

www.theguardian.com

View attachment 202387

The last thing Boris needs now is to be attacked on Canon Rumors.
He never made any claims about sensor size and depth of field.
He only said the chances of getting a shallow depth of field with an Olympus micro 4/3are the same as getting decapitated by a frisbee or of finding Elvis.
It could be the last straw and force him to resign fire some more minions

 

[Lee Jay]

Agreed. My original point still stands, though. Given that TDP defines DLA as the aperture at which diffraction begins to noticeably soften the image, and posts that the DLA of the 90D/M6II is f/5.2, that is not wrong.

I still think it's the wrong thing to do, and I'll tell you why. It gives less technically-inclined people the idea that there's no point in shooting at f-stops slower than they define as the DLA. That idea is wrong in a whole bunch of ways but that chart will leave that idea in people's minds. I know this because I've had people say things to me like, "I like my D700 because I can shoot it at f/12 whereas the 5DsR limits me to f/6" or things like that, which is entirely bogus (and I'm sure you're aware of that and the reasons why).