Cheap/Good value Medium format : The Look

donaldejose

"proportions of the real scene to a certain film or sensor size" Sure I understand that, but it has to do with enlargement quality, not "look." Look should relate to the ratio between the sensor size, the lens f-stop and the lens mm. Those ratios should be duplicatable in FX, unless you need one parameter which doesn't exist, like an f1.4 200 mm lens.

funtagraph

have you ever tried to scale a waterdrop or a snowflake, @donaldejose? I mean, that you get a water drop of 1 gallon content? You can't scale picture/sensor proportions - or prove me wrong. Tiny pictures remain tiny. not matter how big you try to blow them up. you'd scale all flaws of the optics, all imperfections, all noise and all lack of details to the point of becoming obvious.

I guarantee, two pictures of same size with the same FoV but different size Bayer sensors and you'd always prefer the bigger one. There's simply more information in with more energy in a single pixel than the smaller sensor could deliver.

donaldejose

funtagraph: I do not disagree with you but we are talking about two different things. The larger the sensor the less enlargement is needed for a particular photo size. But that is not the "look" of medium format people are talking about above. The reason PitchBlack refers to a 200mm f2 lens is for the ratios I speak about. Obviously, the sensor is still FX size. It is the lens mm and f-stop that creates the MF "look" he speaks about when he talks of compression and DOF.

Ironheart

The difference is to get the MF "look" on an FX, you have to stand further away, because you need a longer lens to achieve the same compression. And to @PitchBlack's point, sometimes that further away might be bigger than your studio, or so far away you lose touch with your model. The "crop factor" from FX to MF is approx. 0.65. This means that a 105mm lens on a FX is a 160mm lens on MF if you want to stand the same distance away. This also means you'll get the DoF and compression of a 105mm instead of the 160mm on the MF.

Now, you can put the 160mm on the FX, and stand further away to get the same compression, but your DoF will increase (just like going from FX to DX). You can compensate of course by stopping down, but if you started at f/1.4 on MF, good luck.

To summarize, the "look" is a combination of DoF and telephoto compression that can only be achieved at a certain sensor size. You can compensate, but only within limits.

heartyfisher

So is it DX is to FX as FX is to MF ? I am thinking maybe.. the compression is just a "non factor" bec in MF you still depend on the focal length of the lense to get the same level of compression between 35mm DX, 50mm FX and 80mm MF.

I know @pitchblack loves his tele lenses like the 200-400 and 200 F2. Is it bec it kind of replicates the MF look? but surely the MF look is not related to compression only bec there are many wide angle MF lenses. Similarly the DOF is surely not the main explanation for the MF look either as most of the MF lenses are around F4 or more. And "detail" .. you get lots of detail in modern FX and DX sensors ..

so what is it ? a combination ?

The "MF" look has been mentioned a lot with the 36mp D800 when it first came out .. what is the clue here ? Detail ? something else ?

heartyfisher

Found this ..

"medium format means bigger film. Bigger film means prettier photos. Simple."

Seems like a nice definition that doesn't help ;-) actually his examples of the medium format look seems right.. but still hard to define...

http://adventuresinfilm.tumblr.com/post/19508541798/medium-format-part-1-why-medium-format

heartyfisher

:-) I have heard that a mobile phone on speaker works :-) they used to use walkie talkies .. but its 2015 now :-)

heartyfisher

...

And yes... all those differences between medium format and FX are pretty much the differences between FX and DX, except another level beyond.

...

I think that is the gist of it ... I probably can replicate it now.. not so much for moving subjects but for static subjects I think its possible .. will play with what I did before but with more lenses and subjects .. should be fun !

WestEndFoto

I have been trying to come up with a technical reason why medium format would have a different look than 35mm equivalent (or FX from DX). I have been fooling around with this site:

http://www.tawbaware.com/maxlyons/calc.htm

calculating depth of field using different circles of confusion as applicable to different sensor sizes. It seems that given a certain depth of field (say a person from their nose to the back of their head), the background is equally blurry. This confirmed my intuition.

It is also interesting that a 50mm DX lens at f/1.4 has the same depth of field as a 75mm FX lens at f/2.1ish. This illustrates the advantage in going to a larger format. Keep in mind that the two examples have an equivalent field of view.

However, this sheds no light on why medium format would have a "medium format look".

Since the field of view is the same, that would not change the look - though a longer lens will decrease the field of view and allow the photographer to control what is in the background. That is one reason that I like a longer lens.

But what would account for a different look and why does Pitchblack see this "look" with his 200mm f/2.0 and even more so with a 400mm f/2.8?

Then it occurred to me that these two lenses, especially the 400mm, are insanely sharp. They are sharper than anything available in a shorter focal length, including the Zeiss Otus 55 and 85.

Just like medium format. The larger the format, the higher the resolution that is achievable.

So maybe what the "medium format look" boils down to is "insane sharpness in the focused plane with beautiful bokeh in the de-focused plane". As an aside, it certainly suggests why some of us like sharp lenses even if we are not printing in huge prints. There may be something at the margin that we perceive that we cannot consciously put our finger on?

I am going to chew on this concept for a while. Thoughts anyone?

Unrelated, this website is also a useful tool for thinking about Airy Disk Diameters, which is essentially diffraction and which f-stop it kicks in.

Finally, the Circle of Confusion (COC) for FX is commonly stated as 0.028844mm (say 0.03, but Zeiss says 0.02501). However, for humans with 20/20 vision, the appropriate COC is 0.01. That may explain why some of us put a higher premium on sharpness than others.

heartyfisher

@westendfoto nice analysis .. I think you are tracking the issue down.. ! :-) however regarding sharpness as mentioned in the article and by my own reckoning, I don’t think it plays a major role in the "Look". Even in internet size images you see the "MF Look". On the other hand .. the Bokeh probably does. Now one thing the calculator doesnt show is the bokeh. I have a feeling that the relative sizes of the circles of lights are probably different given the same FOV and aperture between DX FX and MF even if the DOF is the same.. I am sure we can test this.. just need to work out some calculations ... ( I am not keen to look at my onion rings again .. . )

Ironheart

I think the higher compression of the longer focal lengths has something to do with it as well. Subjects appear flatter and backgrounds closer as you increase the focal length. Did anyone look at this link?
http://en.m.wikipedia.org/wiki/Perspective_distortion_(photography)

"Longer lenses magnify the subject more, apparently compressing distance and (when focused on the foreground) blurring the background because of their shallower depth of field. Wider lenses tend to magnify distance between objects while allowing greater depth of field."

sevencrossing

It is worth remembering MF is anything larger than 24 by 36 mm (full-frame) but smaller than 4 by 5 inches ( large format )

A normal lens is the diagonal of image
A normal lens will give you normal "normal" perspective
APS C DX - 30mm
Full frame FX - 43mm ( for some reason 50mm is often considered a standard lens)
6x 6 - 80mm
6x9 100mm
5"x 4" 150mm

donaldejose

So bottom line is that you can get the same effect by standing further away from the subject? I have seen fashion shoots in Miami Beach shot with a 300mm f2.8 and the photographer was standing some distance from the model.

Ironheart

You can get the compression right, but the DoF will still be different. If you have a really fast lens on FX, you can get there. You need a stop and a half advantage on FX; I think @hearty is going to simulate the MF DoF in post.

funtagraph

I doubt that "you can get the same effect…" @donaldejose. I agree with @Ironheart.

The situation is, you can't get a 40…80 MP sensor just smaller and use shorter FL to get the same "effects". Even if it would be technically possible, those small pixels will never collect the light energy a bigger sensor with bigger pixels get. The smaller sensor… blast, I mean everybody knows the theory what difference it is between DX and FX - and that's only a crop of 1.5.

FX to MF is a crop of 1.8 … 2.3 (roughly and depending on the real sensor dimension). That's just two D810 sensors in one piece for max resolution or two Df sensors for superb noise. I know, it's not that simple, but I don't get the focus on FX and how FX could do an MF "effect" - it just can't.

sevencrossing

how FX could do an MF "effect" - it just can't.

I think the Brenizer method will achieve just that

calengor

It is my understanding that decreasing sensor size increases depth of field for a given aperture, not the other way around. f/1.8 on a DX camera is the same as ~f/2.7 on an FX camera.

Plugging the values into my TruDOF-Pro app and taking into account equivalent focal length and focusing at 2 meters (f/1.4 x 1.5 crop factor = f/2.1, we'll use f/2 for the example below):

Format - Focal Length - Aperture - Total Depth of Field
DX - 50 - 1.4 - 0.08 m
FX - 75 - 1.4 - 0.05 m
FX - 75 - 2.0 - 0.08 m

donaldejose

Sounds good PitchBlack. Maybe the new 300mm f4 on the D810 will be a great and cheap "medium-formatty" portrait combination. It should be more handholdable than the 300mm f2.8, 200mm f2 or 200-400mm f4.

framer

Sorry I'm late to the party...

Two medium format camera's I consider a deal The #1 Bronica GS-1 6x7 system cheap today body w/ 2 - 3 lenses and backs under $1000. Really cheap but works great is an old Omega Rapid M, Rapid 200 or the Omegaflex all 6x7 formats. I've seen systems go $200-300 a few under $100.

heartyfisher

how FX could do an MF "effect" - it just can't.

I think the Brenizer method will achieve just that

I had forgoten what it was called but yes that's what I used for my image of Rei Jade.

WestEndFoto

@westendfoto nice analysis .. I think you are tracking the issue down.. ! :-) however regarding sharpness as mentioned in the article and by my own reckoning, I don’t think it plays a major role in the "Look". Even in internet size images you see the "MF Look". On the other hand .. the Bokeh probably does. Now one thing the calculator doesnt show is the bokeh. I have a feeling that the relative sizes of the circles of lights are probably different given the same FOV and aperture between DX FX and MF even if the DOF is the same.. I am sure we can test this.. just need to work out some calculations ... ( I am not keen to look at my onion rings again .. . )

The calculator does show the bokeh. I just had to come up with a creative way to use it.

I considered three format scenarios:
1.
DX (1.5 crop factor), 266.67mm lens, subject 50m distant, f/4.0, COC 0.01923mm
2.
FX, 400mm lens, subject 50m distant, f/6, COC 0.028844mm
3.
MX (48mm*72mm sensor) (0.5 crop factor), 800mm lens, subject 50m distant, f/12.1, COC 0.057689

Each of these scenarios has a field of view of 5.2 degrees - see the angular field of view calculator on the http://www.tawbaware.com/maxlyons/calc.htm site.

How to calculate the Circle of Confusion COC can be found here:
http://en.wikipedia.org/wiki/Circle_of_confusion

The three scenarios produced a depth of field of 5.395m, 5.3805m and 5.3816 respectively. The differences are trivial and amount to rounding errors stemming from my inability to enter more than one decimal place in the f-stop. They also illustrate that you can achieve the same depth of field with much smaller f-stops when using a larger format. I adjusted the f-stops purposefully to ensure that I am comparing apples to apples.

Now Heartyfisher, you have implied that the site does not test for bokeh. Pitchblack, you seem to be implying that more of the "face" can be in focus while maintaining the same blurry background, which is like saying that the ratio between the circle of confusion at the limit of human visual acuity vs a certain amount of defocus will be different for different formats.

Bokeh and Pitchblack's assertion can be tested as follows:

1.
For each of the above scenarios, multiply the COC by the same number - I used 10.
2.
Calculate the ratio between the original COC and adjusted COC (COC*10) for each of the "Near Focus Distance", "Far Focus Distance" and "Depth of Field".

For DX, FX and MX, these three numbers are 0.68, 2.04 and 14.0.

Therefore, the ratio between the sharpness at the focal distance and blurriness at another distance is the same regardless of format. Once you have adjusted for format size with the correct focal length (crop factor) and f-stop, there is no difference on bokeh between DX, FX and MX.

And it is not compression that is causing the effect, because compression depends on focal length. In the above example, the focal lengths were all adjusted to produce the same field of view, which means that the compression will be the same.

So, what is causing the "Medium Format Effect"?

WestEndFoto

This could be the explanation:

http://reframe.gizmodo.com/why-medium-format-is-so-gorgeous-its-about-more-than-r-1601938278



Or it could be the "Brenizer Method" as described here:

http://www.thephoblographer.com/2014/10/02/medium-format-look-creating-panoramic-portraits/#.VMCOQeknK70

But the Brenizer Method is really equivalent to shooting a wide angle lens really really wide open, say f/0.25 at 24mm on FX. There is of course no FX lens like this, but the Brenizer Method or Large Format would produce the same effect. At the long end, fast telephotos in FX are available.



Or maybe this is the answer:

http://diglloyd.com/blog/2013/20131007_4-Zeiss-Otus-55f1_4-medium-format-look.html

which supports my "gut assertion" that it is sharpness and the general lack of aberrations that are important. But I don't really know, it is just my gut.

heartyfisher

I find it so frustrating reading this thread. Even on individual posts , and links and .. .. on the one hand the is so much good info describing the MF look on the other hand there is so much .. .. @%@ ... misinformation, contradictions and errors.

funtagraph

@PitchBlach I can add, the Otus' 55/1.4 "medium format look" is marketing blurb, at least the "look" bit. The Otus just has clean corners with no abberation in contrasty situations. That's similar to MF, but the porportions of FL, sensor size and pixel density - well, not everything of those facts can be changed by a super lens.

"Inconvenient"? Hmm, I only had a PhaseOne to play around. AF was super snappy, their backs with touchscreen display are kind of something I miss very much on each (!) Nikon. A heavy piece to hold, but I found every button and knob where it has to be. I was used a Mamiya 645 super without prism finder (and no built in exposure meter, not to speak about aperture priority automatic, so my scale of "inconvenient" has some more space in the lower parts

And TTL flash? I don''t use it enough to talk about advantages or disadvantages.

@heartyfisher is there more "misinformation" than in the whole forum? I know, even using a certain camera daily doesn't necessarily mean I know everything about it. That's normal. Problem only starts, if I'd pretend to know everything.

sevencrossing

@heartyfisher is there more "misinformation" than in the whole forum?

when it comes to subjects such as: perspective; dof and Dx vs Fx vs MF. I think misunderstanding is a better term