My thoughts on the Kipon Medium Format "Speedbooster"

[tupp]

4 hours ago, jcs said:

Do you realize that what you are saying is that the lenses are alive and sentient and direct photons differently based on the physical sensor size?

Huh?  How did you read that into my posts?

 

 

4 hours ago, jcs said:

Everything that Mattias posted here is a collective hallucination and focal reducers don't actually work? Or are you just messing with us for kicks? If not, I look forward to your equations and examples showing your concepts in action.

You're going to have to explain how you came to this notion.

 

Again, as the variables are complex, I wouldn't begin to know how to include them in an equation.  Suffice it to say, look/DOF involves more than just f-stop and focal length.

 

I don't see any reason to provide any further examples than the ones that have already been submitted.  If I were to coordinate an equivalence/look test, it would have to compare a tiny format (S16 or 2/3") with a large format (4"x5" or larger), and you would have to be present to ensure properly equivalent combinations of f-stops and focal lengths. 

[kaylee]

AWWW yisssss lets have it out!! @jcs vs @tupp deathmatch!!! TheREMUST BE A WINNER

 

seriously tho when i STARTED posting on this board years ago certain ppl were having this EXACT same argument... and i still dont know the truth. im gonna start a movement like the 911 truthers called... uhm... sensor size truthers? #sensorsizeTRUTH 

[Brian Caldwell]

33 minutes ago, tupp said:

No.  I already addressed this passage previously in this thread.

Let me get this straight - are you denying that the combination of an 80mm lens with a 0.7x focal reducer is a 56mm lens?

[jcs]

26 minutes ago, kaylee said:

AWWW yisssss lets have it out!! @jcs vs @tupp deathmatch!!! TheREMUST BE A WINNER

seriously tho when i STARTED posting on this board years ago certain ppl were having this EXACT same argument... and i still dont know the truth. im gonna start a movement like the 911 truthers called... uhm... sensor size truthers? #sensorsizeTRUTH 

Haha Kaylee I'm pretty sure @tupp is putting one over on us and is joking at this point. If you're still not convinced that it's not sensor size but rather optics that matter with respect to a certain look, Brain is far more qualified and perhaps can do a better job explaining it than I can. Cheers  

[sam]

31 minutes ago, kaylee said:

AWWW yisssss lets have it out!! @jcs vs @tuppwhen i STARTED posting on this board years ago certain ppl were having this EXACT same argument.

Yeah was it 2007 or 2008 when eoshd started? Anyways, I think I've been here a decade, and jcs still hasn't convinced tupp! 

[jcs]

12 minutes ago, sam said:

Yeah was it 2007 or 2008 when eoshd started? Anyways, I think I've been here a decade, and jcs still hasn't convinced tupp! 

I too used to believe in the 'full frame look' myth: http://www.eoshd.com/comments/topic/1917-quick-test-sony-fs700-speed-booster-vs-canon-5d-mark-iii/

Once I ran across the Equivalence equations and did the tests myself, I understood the truth- there's no such thing as a 'full frame look' or any other sensor size look. It's all about the optics. I can still remember what it was like to believe in the myth and have empathy for those who still do.

[kaylee]

46 minutes ago, jcs said:

I too used to believe in the 'full frame look' myth: http://www.eoshd.com/comments/topic/1917-quick-test-sony-fs700-speed-booster-vs-canon-5d-mark-iii/

Once I ran across the Equivalence equations and did the tests myself, I understood the truth- there's no such thing as a 'full frame look' or any other sensor size look. It's all about the optics. I can still remember what it was like to believe in the myth and have empathy for those who still do.

i still honestly dont understand

im not smart enough – i cant do the math, but i totally buy that logic. sounds like it makes sense to me. but then why have i always though that theres a specialness to medium and large format photography, ever since i started shooting 35mm film (with limited experience in medium and large format) over 20 years ago?

im just trying to find the #truth

 

 

1 hour ago, sam said:

Yeah was it 2007 or 2008 when eoshd started? Anyways, I think I've been here a decade, and jcs still hasn't convinced tupp! 

omg! ? its been going on that long? the eternal battle

[Mattias Burling]

53 minutes ago, jcs said:

I can still remember what it was like to believe in the myth and have empathy for those who still do.

Ok, just so we are on the same page.

You belive that if I take a paper magazine cover and cut out a x2 crop with actual scissors it will become 2 stops darker as I lift it of the paper?

Because right now it sounds to like you have empathy for me that dont belive in such magic.

Exposure doesn't change with sensor size = if you open up the aperture to get the same dof you also lets in more light and change the exposure = it wasnt an "equivalent" lens.

Imo applying crop factor to aperture is just confusing and has no meaning. I use it for focal length only when talking to beginners.

An experienced photographer wants to now what lens I used and dont care about a bunch of "equivalent" nonsense. He/she knows what a 20mm does to the camera and/or film we are discussing.

[jcs]

26 minutes ago, Mattias Burling said:

Ok, just so we are on the same page.

You belive that ig I take a paper magazine cover and cut out a x2 crop with actual scissors it will become 2 stops darker as I lift it of the paper?

Because right now it sounds to like you have empathy for me that dont belive in such magic.

Exposure doesn't change with sensor size = if you open up the aperture to get the same dof you also lets in more light and change the exposure = it wasnt an "equivalent" lens.

Imo applying crop factor to aperture is just confusing and has no meaning. I use it for focal length only when talking to beginners.

An experienced photographer wants to now what lens I used and dont care about a bunch of "equivalent" nonsense. He/she knows what a 20mm does to the camera and/or film we are discussing.

Hey Mattias, if after everything I have posted, and everything Brian Caldwell, the designer of the SpeedBooster has posted, has not convinced you that there's no such thing as a full frame or medium format look, no worries. I wasn't trying to win an argument, only to share what I have learned with others. Have you tried working through the equivalence equations, setting up the camera and reviewing the results as I did here? If not, how can you dismiss it if you haven't tried it? If you have any questions about setting it up, feel free to PM me. It would probably make a cool video that a lot of people would be interested in seeing

[kaylee]

this is actually more like a tag team event than a one on one match... theres factions

[tweak]

It seems to me like people are simply confusing things. "Look" is a pretty ambiguous word. If you want to argue, stop talking about "a look" and start talking about specifics. Arguing there is no "full frame look" (or any other format look) is silly, because clearly there is a look to different formats (whether that's due to the lenses alone, or a combination of sensor + lenses is debatable, but clearly there's different characteristics at play).

I assume what most people really want to argue here is a matter of "equivalency", which seems to be interchanged with the word "look" far to often in this thread for my likings. As such it seems (and reads) as though people are actually arguing about two or more different things whilst it's being taken as all one in the same...

[kaylee]

2 hours ago, tweak said:

It seems to me like people are simply confusing things. "Look" is a pretty ambiguous word. If you want to argue, stop talking about "a look" and start talking about specifics. Arguing there is no "full frame look" (or any other format look) is silly, because clearly there is a look to different formats (whether that's due to the lenses alone, or a combination of sensor + lenses is debatable, but clearly there's different characteristics at play).

I assume what most people really want to argue here is a matter of "equivalency", which seems to be interchanged with the word "look" far to often in this thread for my likings. As such it seems (and reads) as though people are actually arguing about two or more different things whilst it's being taken as all one in the same...

so is it fair to say that in practice its an artistic argument vs a technical one?

[Bioskop.Inc]

I love this forum for the fights that break out! Sometimes, I do wonder how much of it is down to trolling & how much is down to confussion over terminology.

The way i see it, is that there is no such thing as a "sensor look", what it we are really talking about is how a sensor transposes the qualities of a given lens to create a picture or image.

I have noticed this with the swirly bokeh madness created by the Helios 40-2 85mm f1.9: depending on how big the sensor is (FF, APS-C or s16mm), will have have an effect on how much of the lens circle the sensor will be able to use in order to take a picture. So, no matter what sensor/camera you use, you'll always get the insane swirly bokeh, because that is the LOOK that this lens produces.

So when you put the same lens on different sensor sizes, you're not creating a new LOOK, just a different focal lenth & interpretation of the lenses characteristics?

Shit, now I think I am confused!

[webrunner5]

Well I will jump in. I have been doing this a hell of a long time between film and video. The main advantage of a Digital FF, MF is their ability to gather light, or fill factor in the Sensels, or Wells. The bigger the microns on a sensor the more light they capture. Micro Lenses also help lately with this. So they are better in low light, bigger pixel size = more sensitivity is the end result. That is one reason a camera like the Sony F3 is good at low light, s35 sensor and big ass microns. Same reason a Sony A7s is great at low light. small MP count, big microns compared to a Sony A7r with smaller microns at 36MP = better low light.

Also they end up being better for DoF. You can isolate subjects way better with larger sensors or. Some call it the 3D effect. Light gathering ability and DoF applied to film back in the day just as it does now with Digital Sensors. Sensors now are a mimic of film in a strict sense. They were designed to replace, simulate film, and they have to follow the same rules of Physics. The whole modern world of photography, Video is based on the 35mm aspect ratio as being the Holly Grail. Anything bigger is better, anything smaller is worse. And it isn't going to change. Any gains made in say a m4/3 sensor can be applied to a 35mm sensor. so m4/3 will Always be worse than a 35mm, always.

So this MF thread is pretty much has an advantage in 2 areas, more light gathering ability and better DoF isolation. Other than that I can't think of any thing better, and they are actually worse in a sense because the camera weighs more and the lenses have to be larger in diameter and length. Both sort of a negative in the handling of them.

As to putting big ass lenses onto little sensor cameras, well that does not change DoF, or Fill Factor of the Sensor at all. You are not going to get anymore light into a m4/3 sensor by using a FF, MF lens on it. The image circle is too big to matter. It changes the look some, because every lens maker has a LOOK to them, like them or not. And the older MF lenses were made for film with no coatings applied to them now like they use.

[fuzzynormal]

I learned still photography on 35mm film, and that's typical of what people often talk about regarding "equivalence" online; which makes it easier to grasps from the get go the whole debate about it all.  If you came into the camera enthusiasm/hobby these days, god help you.  Ignorance mixed with all the jargon and all the different sizes of things?  Yeah, we can understand why it'll make one's head spin.  Mine still does because the maths on all this are not symmetrical.  Sliding scales, expotentials, and numerical gradients.  Physics stuffs. 

But here's my rather redundant summation and basic understanding: shooting a 50mm lens set to f2 on an M43 is "equivalent" to what would happen (circle-of-confusion-depth-of-field-wise -- not exposure-wise) if you put a 100mm f4 on a full frame sensor.

Here's where the frustrating part comes in, I think.  Folks use f-stop to generally talk about what it take to achieve a certain depth-of-field.  You know if you're shooting glass wide open, you're going to be increasing the out-of-focus stuff in the frame, 'kuz that's how lenses work.

Director: "Hey, we need shallower DOF on this shot, go to a f2.8"

DP "Got it."

Those folks ain't talking directly about how many photons the want passing through the lens.  Rather, they're talking about creating a visual look.  So "f-stop," becomes an easy marker to achieve a certain visual result.  That term can get convoluted in the broader technical consideration.  

(And, hoo boy, let's not even bring in t-stops to this part of the discussion, lest brains start to implode)

The thing about full frame sensors, and even larger sensors, is that you can achieve the very shallow depth-of-field easier and with wider lenses than you can if you have a smaller sensor.  So, when doing a portrait shot, one can whack some back ground out of focus effortlessly and rather affordably with a cheap 50mm f2 lens on a full frame.  

Yes, you can get such "equivalent" DOF with something like M43, but then you're spending a lot of cash to get more exotic lenses that'll shoot f0.95 or something. 

The good thing about full frame, pragmatically speaking, is that you can easily get shallow DOF while closer to a subject.

This is cool because when you have a wider field of view and shallow depth-of-field, the visual creates a sort of 3D pop.  The in-focus bit separated easily from the background.  Not to mention that motion in wider field of view has a different visual quality.  I believe this is referenced as "parallax," which can also has a quality that should be taken into account.

Also, again, FF lenses cost less to accomplish the same shallow DOF/FOV than M43 lenses.

Other than that, I think a lot of people on-line in camera forums maybe don't have comprehensive wisdom, (including me) but certainly have a lot of notions they want to assert.  More often than not, it seems like those assertions are wrapped up in some rhetorical ego.  Seems like people want to hear and write affirmations about their current version of reality rather than actuality.  So it's easy to understand why it's all a mix-up for readers of these words.

The phrase "circle-of-confusion" is apt, in more ways than one ain't it?

For me, I have a general knowledge of what stuff looks like simply because I've played around with this crap for decades.  All one really has to do is put their eyeballs on results they create themselves and it's all obvious.  It may remain inarticulated, but it does become obvious.

[hyalinejim]

48 minutes ago, fuzzynormal said:

Seems like people want to hear and write affirmations about their current version of reality rather than actuality.

This sums up the post-fact world we are currently living in beautifully!

 

8 hours ago, Mattias Burling said:

You belive that if I take a paper magazine cover and cut out a x2 crop with actual scissors it will become 2 stops darker as I lift it of the paper?

No, but you'll more easily see the half tone pattern if you fill your field of view with it. Or, to put it another away it captures less ink. I don't know why you're getting into this analogy as what you're getting at relates to the explanation of why smaller sensors tend to be noisier. I don't think anyone has suggested that exposure changes with sensor size.

8 hours ago, Mattias Burling said:

Imo applying crop factor to aperture is just confusing and has no meaning.

Well, it's not confusing or meaningless to me and to others who understand the principle of equivalence. I use it to calculate what focal length and aperture will be required to match field of view and depth of field when moving from one format to another. For that reason alone, it's worth developing a coherent understanding of it.

@tupp all those small differences in your AB comparison are of course accounted for by the things that you mention, entrance pupil distance, diffraction, etc. etc. These factors don't enter into equivalence calculations, nor do they contradict them. Their effect is so minimal as to be altogether invisible to the average viewer, despite their dramatic apparence to you. Relative to the changes in image wrought by changing focal length, aperture, or sensor size, their effect is negligible.

Equivalence is theoretically sound and empirically verifiable. I would encourage dissenters to investigate it more closely and carefully. What does it predict? Do the results match the predictions?

[BTM_Pix]

And by a strange coincidence, a post has just popped up on DPR with an ad hoc equivalence test someone has done with MF,FF and APS-C.

As an aside, the amount of gear he seems to have had with him on a (presumably) non-photographic related business trip makes we wonder if he needs sherpas when he's going on a fully fledged shooting outing.

https://***URL removed***/forums/thread/4125975

[jcs]

10 hours ago, kaylee said:

so is it fair to say that in practice its an artistic argument vs a technical one?

The concept of equivalence is a technical one, math and physics. The perception of specific looks is an artistic one. Here's APS-C, full frame, and medium format compared with equivalent settings (thanks @BTM_Pix , from https://***URL removed***/forums/thread/4125975 ):

Are the 3 shots pixel perfect? That's not possible 'in the real world' (via simulation it is easy if we don't simulate truly random noise). Consider that if you take two consecutive shots 'in the real world' with the same camera and lens and change nothing, the two shots can't be pixel perfect because of noise alone. The Earth rotates, clouds move, wind blows, etc. However as the photographer who did the test states, the images look more alike than different, and share the same look or character.

The argument has been that sensor size alone, which gives rise to special looks, such as 'the full frame look' and 'the medium format look' and 'the large format look' are specific and real, where the sensor size alone gives images a unique, identifiable character and specific look.

The actual looks or characters that people are really referring to are:

1. Shallow depth of field
2. Lens artifacts, including bokeh 'style', highlight behavior, contrast, sharpness, color, distortion, defects, etc., as the lens is a kind of optical transfer function or filter, ranging from clinical and accurate such as Zeiss, to something wild like a Helios or Cyclop

That's it, there is nothing more. Even with different cameras and lenses, when set up for equivalence, as in the above example, the average person can't tell which camera shot which image as they all have a very similar look or character when using lenses with similar characteristics. The fact that a focal reducer (Speed Booster) works as expected should be sufficient evidence that sensor size is not responsible for any specific look or character.

Photography and filmmaking are very technical forms of creating art. Everyone on this forum has the ability to do the simple math and set up their cameras for equivalence:

To get the full frame camera equivalent to the crop sensor camera:

1. Multiply the focal length of the lens by the crop factor
2. Multiply the aperture by the crop factor
3. Multiply the ISO by the crop factor squared.

Example from my website http://brightland.com/w/the-full-frame-look-is-a-myth-heres-how-to-prove-it-for-yourself/:

Let’s do one using the A7S in FF and APS-C (Super 35) crop mode. The crop factor is 1.5. We’ll set up the camera as follows using the Canon 70-200 F2.8L II and the Metabones IV Smart Adapter:

• Super 35 (APS-C mode on): 70mm, F2.8, ISO 800
• Full frame (APS-C mode off): 70mm*1.5 = 105mm, F2.8*1.5 = F4.2, we’ll use F4, ISO 800*(1.5*1.5) = 1800, we’ll use ISO 1600

Can you tell which is full frame and which is crop without cheating or using a blink test? At the pixel level the images are different, however the overall look or character is considered the same.

Here's a friendly challenge to @tupp, @Mattias Burling, @Andrew Reid, and anyone else who feels that each format has a specific look which can be characterized:

1. Do your own equivalence tests
2. Share the results online
3. Do not label the images or filenames (so people can't cheat)
4. See if anyone can identify which images are what format, and what are the specific characteristics which allow them to tell the formats apart

If anyone needs assistance with the math or settings I can help and I'm sure there are others here who can as well. Remember I used to believe in the full frame look too until I did these tests.

Anyone wanting to continue arguing without doing these tests for themselves is either lazy, blocked by their ego, or just enjoys arguing. Nothing wrong with being any of those things, it's part of being human, however we won't be able to take you seriously in this scientific debate  

[tweak]

This is awesome, I love how everyone constantly contradicts themselves and are arguing in circles about things I don't really think anyone here disagrees on for the most part. 

[BTM_Pix]

Equivalence seems to be in the air on all sites this week.....

Steve Huff weighs in with a different take on it, eschewing the maths and saying "Yeah but I have this 35mm f1.4 on FF and I mainly shoot it wide open so I'm not compromising that and setting it to 2.8(*) just so I can properly match this 23mm f2 APS-C and lose that power".  Essentially in thats respect he's berating APS-C for bring a knife to a gun fight but still asking the question "But what does it actually LOOK like in comparison?" and "Is there THAT much difference to the LOOK between f1.4 and f2 with the equivalent focal length?". 

I think the images he's produced to do this with will support no ones side of this argument as some may say the only equivalence he's really proven is that its possible to take bang average images equally well with a $9000 or $1000 dollar camera. 

http://www.stevehuffphoto.com/2017/03/03/quick-compare-full-frame-dof-vs-aps-c-dof-at-the-same-aperture-leica-vs-fuji/

(* He should have set it to 3.2 of course but he's not arsed about the numbers so its moot)