Crop Factor with ISO and Aperture - Response

That video was confusing and to a point disinformation. As you said with equivalent lenses the same exposure settings on different sensor size camera’s will give you the same brightness. Did the test myself.

You guys are dead wrong. Depth of field has nothing to do with sensor size. To the novice you look brilliant, to the people who know, you look ridiculous and stupid

This response is silly because the problem is that manufacturers Already use the 35mm equivalence when listing focal lengths in the cameras they sell. Yet they do intentionally leave out the focal length equivalence. That is what he is advocating for.

This response is silly because the problem is that manufacturers Already use the 35mm equivalence when listing focal lengths in the cameras they sell. Yet they do intentionally leave out the focal length equivalence. That is what he is advocating for.

I'm glad that you made the video to explain the other side of the truth.
The whole Tony and DPreview theory about building up a 35mm sensor as digital photography standard is more like politics rather than real photography matter.
When they failed to add up more proof to stand for the theory, they added up the sensor SNR formula, which is totally impractical since the sensors cross generations, pixel density, brands and technology, do not share the same SNR standard at all, say Foveon X3 vs. Fuji Super CCD vs. APS-C sensor used in A6000, SNR wise, the formula just does not make sense, don't even mentiuon that they were trying to build the whole aperture theory on that.
It's not really about what benefit the photographers, it's more about competition of the discursive power between manufacturers and media, or even SONY+Media vs. others, both sides are trying to build up a new standard for the digital photography age, on top of the simple original mathematics of photography.

I was 100% behind Tony with what he was saying in his video but you've really opened my eyes here. Why compare everything to 35mm? It's no more a standard than medium format or all the sizes that came before it.

The way things are labelled currently helps match exposures and I think that's logical.

It's worth noting that smaller sensors have more noise and larger depth of field using the same exposure settings but, as you said, it's good enough to know that and carry on.

I couldn't disagree more. Imagine a beginner that saw someone's work using a 50mm 1.8 on a FF. This beginner understands only the basics of aperture, not all the math behind. He WILL believe that using a point-and-shoot 2.8 camera will give him similar results as a FF 2.8.

You missed Tony's main point, crop factor is only useful when you want to make identical images with two different sensor size cameras, it's the way to compute what you need in order to make identical pictures - nothing more, nothing less.
So it's useful for users of cameras of difference size sensors, if you only have one camera or all your cameras have the same sensor size, then crop factor is meaningless.

I like this video. You explained your position well and you were civil about it. That can be rare in the photography world. However, I don't understand how your way of doing things is better or less confusing. If one uses a single standard to compare all formats to, that helps people understand what to expect. It immediately gets the point across that larger formats have gear which provides less noise and more background blur. Simply saying that one format "has less noise" or "has more depth of field" does not tell a person by how much there is a difference, and it may cause people to learn stuff that isn't mechanically correct. The format itself doesn't decide how a picture will look: the lenses do. It's just that lens manufacturers don't bother making fast lenses for smaller formats so that you get the same total light. Instead they convert the focal length but not the aperture. Much cheaper!

You need to back this up with examples photos you took yourself like Tony did...otherwise it's just your opinion and I frankly have no idea if you're being sponsored by camera companies to say that or not.

no, you dont really get what tony said, yes, the exposure will be same when you use same setting on both full frame and mft camera but the noise level is different, thats because they.are getting different.amout of.light, to reack.same brightness, iso pull it up.just think about it the amount of light is different why you get same brightness

Very good explanation.
SO I use a 1.6 cropped Canon and Pentax 50mm 1.4. I know my lens is 50mm and 1.4... It sufficeth me by looking at it ;). BUT will a picture with my camera at 1.4 look like one at 2.24 in its full frame equivalent?

where can a normal, middle aged english teacher go to get an explanation of this type of things to choose a decent camera that she can use to preserve memories of her growing family?

So if Tony Northrup is right then both medium and large format lens, Hassleblad etc, shoud be seen in terms of full frame cameras lens

I am still not understanding why Tony Northrup implies crop factor impacts lens speed.

My understanding is the x2 crop factor discussed in one example applies to depth of field and field of view.

In the case of the LUMIX 12-35mm f/2.8, the lens speed/brightness remains f/2.8 but the field of view and depth of field are the perceived equivalent - in 35mm terms - of a 24-70mm f/5.6 when the x2 crop factor is applied. 

I think the fact we use an f-stop value to describe both lens speed AND depth of field and we refer to both values as "Aperture" is adding to the confusion.

While a sensor's physical limitations may impact light sensitivity and noise, crop factor does not impact lens speed.

Thanks. :)

The difference in DOF might be the first and most apparent thing if we don't multiply the aperture by the crop factor, but it is not the ONLY thing as I'm taking from Tony's points - it's about how much harder your sensor has to work to gain itself up to greater sensitivity possibly to the point of introducing grainy noise.  This is not a factor of small sensors being "noisier" than larger ones as they are NOT - it's about how much light overall hits the sensor and the photosites (less on smaller sensors and photosites), and whether you have the optics to counterbalance this, as opposed to the ISO being boosted towards creating hell in your image quality.  I see it in my own equipment ranging from very small sensors to 1" to micro-four-thirds.  Try freezing action at the end of a long 600mm 35-mm equivalent zoom - let's say it's labelled f/5.6 or "mis-labelled" that way Tony might say - made up of glass that's much smaller than a zoom lens labelled f/5.6 for a 35mm sensor, but made smaller to match a much smaller sensor.   You CAN'T freeze it - the lens is "slower".  The optics will act like something much worse than f/5.6 for 35mm requiring a slow shutter and/or high ISO just to expose the hopeless blur you get to a brightness you can see!  You see?  I like to THINK of my LX7's f/1.2 lens for a VERY small sensor or my Nikon 1 f/1.8 lens for a 1" sensor or my GH2's 14mm pancake lens as "fast" but the LX7's f/1.2 is no better than my f/2.5 for the bigger sensor.  NONE of those lenses are nearly as "fast" as 35mm lenses labelled with the same f-stops - lenses for smaller sensors would be have to be much faster and labelled with much smaller f-stops to be equivalent - at least for NOISE and DOF - you see?  But for VIDEO I LOVE what I've got - no need for too shallow a DOF, and some noise/grain is forgivable (and many larger sensors introduce video moire/aliasing/false colour distortions).  But are we too forgiving of the photo IQ and mis-marketing about "35mm equivalence" when the 35mm f-stop equivalent is left out?

I understand your argument from the perspective of someone who knows the difference in sensor sizes and crop factors. But many folks will just go to a store and compare the marketed specs and use that as the buying decision. You need to have a standard/specification to compare to. For your argument, a car and a school bus are different vehicles but the actual mpg on a car might be 40 and only 10 on the bus. I would hope the window sticker tells me this and the tests to achieve the mpg ratings are equivalent (using EPA testing methods). You are arguing the bus can state whatever they want because it's a bus and you know it's a bus and not a car so it's ok for the bus's windows ticket to claim 40mpg?

This is really not a very useful video. Tony can not be right and wrong at the same time, decide which it is. Watch the video again, Tony said (and showed) that the camera manufacturers sell lens as fulframe equivalent, this was not something he came up with. The argument from Tony is that if they market it with the full frame focal length equivalent then they must also market what the full frame aperture equivalent is.
The fact that we talk about crop factors of 1.5 tells us that full frame has been the equivalent since the inception of digital photography.
The discussion would clearly not be for you, as you said, you know already, but what about those who buy for the bokeh of a 2.8 adn can't get it? They need to know about the difference.
I hate when people misrepresent others who might not have the time or ability to defend themselves.