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Andrew Reid

Hasselblad mirrorless camera

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2 hours ago, Brian Caldwell said:

there is no magic to be found here.

 

the magic comes from the available optics for a given format.

 

1. you cannot buy a 60mm/1.4 aps-c lens equivalent to an old leica summicron 90/2 when used on full frame.  yes you can stick a 0.7x focal reducer on there, and I have done so (with the sb ultra on a a7rii).  the amount of defocus is the same but the rolloff is quicker on the focal reduced lens on aps-c.  the in focus areas are also drastically inferior, and there is significant reduction in fov, and added distortion.  all of these attributes contribute to the advantage of the larger sensor.

2. you cannot buy a 50mm/1.4 lens for full frame that is equivalent to an 80mm/2 when used on medium format wide open.  close down 1 stop respectively and the real world advantage of medium format becomes even more pronounced.  

 

I really wish there was a full frame lens system capable of acheiving the same look from my mf camera since i'd no longer be limited to running 80iso.  at the moment the limitation of slower lenses and 80iso means i am confined to flash work or daylight shooting.  until yourself or someone else designs and manufactures a viable alternative for smaller sensors the professionals will continue to buy into the phase one system for remortgage worthy money!  

 

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25 minutes ago, jcs said:

Are you saying that any effect such as 'DOF falloff' are not real effects or are related to a particular MF lens design, and not the physics of light imaging a subject on a larger sensor size? (xCyclops uses a 5D2 to capture a projected image on a plane). 

"DOF falloff"  seems like a really poor term.  How about simply "defocus", or perhaps "MTF as a function of defocus" - which I think is what people actually mean.  In optics this is referred to as "through-focus MTF", and its a standard and useful way to characterize a design.  It will vary from design to design because it is strongly aberration dependent, but it has nothing to do with sensor size.

One advantage that larger formats have is that you can use a smaller relative aperture to achieve a given DOF.  Since aberration correction tends to be very non-linear with respect to f/# you often wind up with better correction on a larger format.  For instance, I used to shoot 11x14" film a fair amount, and aside from an advantage in film grain it allowed me to shoot at f/16 instead of the ~f/1.4 I would have had to use on 24x36 format to achieve an equivalent picture.  Focal lengths scaled accordingly, naturally.  At f/16 the ultra large format lens was nearly diffraction-limited, whereas a small format lens at f/1.4 is nowhere near that limit.  Of course, as you depart from such extremes in aperture any potential optical differences between large and small formats begin to disappear, and these differences are further minimized by improved sensor quality.  So that ridiculously huge view camera stays on the shelf these days!

Regarding the argument about whether a long lens on a large format has less perspective distortion than a proportionally scaled lens on a smaller format, the answer is "no".  In terms of perspective and geometry, all lenses mimic the behavior of simple pinhole cameras - with the possible exception of rectilinear distortion which is generally a non-issue.  One other thing to be aware of is that larger formats require a larger magnification, which essentially means you are using a longer lens than you may think you are for close-ups.  For example, when shooting close portraits on 11x14" I was typically shooting at around -1x magnification, which effectively doubles the length of the lens.  However, when you take this effect into account any potential discrepancies go away, and you are left with the stark reality that larger formats really don't offer any special "magic".

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21 minutes ago, Brian Caldwell said:

"DOF falloff"  seems like a really poor term.  How about simply "defocus", or perhaps "MTF as a function of defocus" - which I think is what people actually mean.  In optics this is referred to as "through-focus MTF", and its a standard and useful way to characterize a design.  It will vary from design to design because it is strongly aberration dependent, but it has nothing to do with sensor size.

One advantage that larger formats have is that you can use a smaller relative aperture to achieve a given DOF.  Since aberration correction tends to be very non-linear with respect to f/# you often wind up with better correction on a larger format.  For instance, I used to shoot 11x14" film a fair amount, and aside from an advantage in film grain it allowed me to shoot at f/16 instead of the ~f/1.4 I would have had to use on 24x36 format to achieve an equivalent picture.  Focal lengths scaled accordingly, naturally.  At f/16 the ultra large format lens was nearly diffraction-limited, whereas a small format lens at f/1.4 is nowhere near that limit.  Of course, as you depart from such extremes in aperture any potential optical differences between large and small formats begin to disappear, and these differences are further minimized by improved sensor quality.  So that ridiculously huge view camera stays on the shelf these days!

Regarding the argument about whether a long lens on a large format has less perspective distortion than a proportionally scaled lens on a smaller format, the answer is "no".  In terms of perspective and geometry, all lenses mimic the behavior of simple pinhole cameras - with the possible exception of rectilinear distortion which is generally a non-issue.  One other thing to be aware of is that larger formats require a larger magnification, which essentially means you are using a longer lens than you may think you are for close-ups.  For example, when shooting close portraits on 11x14" I was typically shooting at around -1x magnification, which effectively doubles the length of the lens.  However, when you take this effect into account any potential discrepancies go away, and you are left with the stark reality that larger formats really don't offer any special "magic".

So DOF behaves the same no matter what magnification? Imagine the same lens design, scaled 2x, same focusing distance, same pupil sizes (same, pupil relation hence the same lens design), just double the magnification (double focal length), will the DOF always behave/be the same (the resulting image will be viewed at the same size)? -All in all, an equivalent situation, just double the focal length, double magnification-

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In order for sensor size to have a real effect on the captured image, the math and physics must predict that at least one component changes with sensor size for the final image. I noted that in the DOF simulator the Circle of Confusion (CoC) changes with sensor size, and the CoC has defined limits based on sensor size here: https://en.wikipedia.org/wiki/Circle_of_confusion . My understanding is that just means the limit for sensels on the sensor to resolve what will become a single dot (not blurry). This may have effects on real-world physics and sensel optics (CFA, low pass filter, etc.) which could explain real-world differences in imaging with different sensor sizes.

Unless there's a single parameter in the math model that predicts some kind of variance with sensor size, any effects in the real-world are due to optical variances and will probably be relatively subtle effects. In the extreme case of something like the (x)Cyclops, it looks like the in-focus region is in really good focus, and the near and far defocus regions are out of focus, with the 3 regions being somewhat constant in appearance, almost like a sharp photo where depth-constant Gaussian blur is applied to the foreground and background (as we can simulate with Snapseed Tilt-Shift simulation etc.), instead of nearer objects being progressively more out of focus and more distant objects the same. This is happening, but it looks 'slowed down' and thus some kind of non-linear function.

How would such non-linear effects be modeled by the math & physics? The concept of CoC means the beginning of the in-focus region is focused so that a dot can be fully sensed and not blurry at all, all the way to the end of the in-focus region, thus the entire DOF range is in focus. Just before and just after, the points are now blurring so that the sensor no longer can resolve them as a point anymore. Intuitively this is all linear. Thus how would the math describe non-linear behavior for the 'through-focus MTF'? One way would be non-linear effects of lenses, which of course is not due to the sensor size itself, and could thus be done for many different sensor sizes if desired and/or physically possible. Again, a ray-tracer which simulates photons through 'perfect' optics could be used to explore this.

I am opened-minded that there could be an interesting effect not predicted by the math, even if a common side-effect of MF lens design. However, it doesn't seem likely as if there was some 'magic', there would be a huge market opportunity for a MF to FF SB and that hasn't happened (especially as richg101 pointed out the low ISO limits of MF sensors). Real world examples using 'equivalence' again would be helpful to figure out either way what, if anything interesting (and real) is happening.

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11 hours ago, jcs said:

However, it doesn't seem likely as if there was some 'magic', there would be a huge market opportunity for a MF to FF SB and that hasn't happened (especially as richg101 pointed out the low ISO limits of MF sensors). Real world examples using 'equivalence' again would be helpful to figure out either way what, if anything interesting (and real) is happening.

A MF to FF speed booster is not a viable product because of a few problems:-

1. a good quality optic will be very expensive.  the Kipon unit won;t perform as well as the speed booster ultra, and as shown on my tests a few pages up, even the speed booster ultra negatively affects the overall image quality when compared to a straight lens on full frame.  add to that the need for electronic contacts to use lenses like the contax645 or rolleiflex hy6 'digital ready' lenses.  the cost will mean the customer base will be limited.

2. Most speed booster purchasers do so to get around having to pay for a full frame camera.  Therefore they'll also be less likely to invest the huge amounts in MF glass that (assuming a focal reducer were optically clear) will actually be worth focal reducing.  a 110mm/2 hasselblad, a schneider 180mm/2.8, a schneider 80/2, contax 80/2.

3. because the likelihood of the focal reducer being of good enough standard (ie, better than a sb ultra) being almost impossible, and the likelihood that hardly anyone will be able to acquire a desirable fast mf lens, the likelihood that an end result will exceed a fast full frame lens, let alone meet that of what is possible on medium format is slim.  

 

All said and done, I'll be buying a kipon mf to ff focal reducer, but in no way do I expect it to deliver the same quality I get from the same lens on MF.

 

 

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The mf to ff focal reducer will be better because it only has to deliver f 1.4 (vs 0.8 from the ultra, I don0t recall the exact number)), a speed booster for 6x9 to 645 will be even better limited to just f1.8-f2. It would be funny to see 100$ lenses outperform 6000$ otuses, but I guess this is reserved for panavision for the time being.

But hey, the emperor is naked and stuff, still waiting for an answer.

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Nice,,,, not a bad price either!

There is some kind of video mode at least. If they have somehow snuck in the raw video mode of their big cams, i'm in (yes, very unlikely).

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The body looks nice, but don't people think it's a bit silly to carry a bunch of lenses, each with a huge medium format flange? I don't think they're getting around the physics. Same thing happened to the Sony A7 series cameras. Upon adding a G-master lens, it's the same size as its DSLR counterpart... the only difference is that the DSLR user will only have ONE integrated flange on the body to carry around.

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28 minutes ago, John Matthews said:

The body looks nice, but don't people think it's a bit silly to carry a bunch of lenses, each with a huge medium format flange? I don't think they're getting around the physics. Same thing happened to the Sony A7 series cameras. Upon adding a G-master lens, it's the same size as its DSLR counterpart... the only difference is that the DSLR user will only have ONE integrated flange on the body to carry around.

a 80mm/2 designed for what looks like the sony 50mp cmos would be small and lightweight - no heavier than a 50mm/1.4 for full frame.  The lack of mirror means the system benefits in the same way a leica M system benefits - small lenses due to not needing to be placed 45-75mm from the sensor to clear the mirror.  think scaled up Loxia lenses.  fast, compact, very high quality.  

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34 minutes ago, richg101 said:

a 80mm/2 designed for what looks like the sony 50mp cmos would be small and lightweight - no heavier than a 50mm/1.4 for full frame.  The lack of mirror means the system benefits in the same way a leica M system benefits - small lenses due to not needing to be placed 45-75mm from the sensor to clear the mirror.  think scaled up Loxia lenses.  fast, compact, very high quality.  

I just hope it doesn't run into this type of situation. Three FF cameras to scale: notice the mirrorless one has an enormous flange. I think it's just physics.

a7RIIvs5DsRvsa99_24-70mmf2.8-800x353.jpg

Petapixel had a whole article on this here:

http://petapixel.com/2016/04/04/sonys-full-frame-pro-mirrorless-fatal-mistake/

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7 hours ago, ntblowz said:

The smallest medium format camera ever!

Yes, small camera, but big or slow lenses. Am I wrong? You still need to cover that sensor. People often say mirrorless is about size, but I think it's mainly about features (EVF, adaptors, etc.). Sensor size is about size.

For video, I doubt this camera from Hasselbald will provide what you need (readout and feature set) for your next IMAX feature... then again, maybe it's the step in the right direction people have been waiting for and it's going to sell like crazy.

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11 hours ago, John Matthews said:

That article sounds like it's written from the perspective of someone who's never owned a mirrorless camera.

A mirrorless setup is most definitely smaller and lighter. Indeed, there are some situations (and Petapixel seems to have cherry-picked all of them) where the size difference doesn't really add up. But I can tell you, my A7s + Sony 70-200 is significantly lighter and certainly smaller than a similar Canon setup. As is my A7s + 24-70 or 16-35.

I would suggest that in this particular case, the reason Sony mirrorless has taken off like it has, has actually very little to do with the fact that it is mirrorless. I would suggest that features like Full frame HD video downscaled from 4k with large dynamic range and Slog (and in-camera 4k!) is the main reason people bought it for video. Best looking full frame DSLR footage on the market (without hacking the camera). Huge MP counts, IBIS, and importantly, the ability to adapt lenses - particularly PL lenses (for video anyway). Yes, as the article says, adapters can be cumbersome or annoying, but that's the case with any camera system. If you buy a camera system partly because of the adaptability of the mount, you can't then complain about using adapters.

Anyone who thinks the primary reason the A7 series is a winner is the fact that it's mirrorless isn't paying attention. The fact that it is mirrorless may allow some of these features to be available, but I think most people are buying for specs and features. 

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There was a rebuttal to that article. It's here:

http://petapixel.com/2016/04/05/defense-sonys-pro-mirrorless-cameras/

In it, even mirrorless owners agree that mirrorless is not about size. I agree that people love the features about the A7 series (when they work). But how many of them bought these cameras thinking they would be lighter and smaller? I'm thinking there were many.

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9 minutes ago, John Matthews said:

There was a rebuttal to that article. It's here:

http://petapixel.com/2016/04/05/defense-sonys-pro-mirrorless-cameras/

In it, even mirrorless owners agree that mirrorless is not about size. I agree that people love the features about the A7 series (when they work). But how many of them bought these cameras thinking they would be lighter and smaller? I'm thinking there were many.

Overall, mirrorless is smaller and lighter, and as the rebuttal argues, most of the pictures in the original article uses the absolute biggest lenses available for the E mount, and compares them with average size, or smaller DSLR lenses.

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22 minutes ago, jax_rox said:

Overall, mirrorless is smaller and lighter, and as the rebuttal argues, most of the pictures in the original article uses the absolute biggest lenses available for the E mount, and compares them with average size, or smaller DSLR lenses.

Is it possible that Sony's e-mount was originally made for APS-C, but then they realised that they could put a FF in it? Those G-master lenses are the state-of-the-art from Sony- the absolute best work they have in 2016, yet they still have that huge flange on them. Why isn't Sony producing wide, fast lenses for the mount, ones that don't have a massive flange? Correct me if I'm wrong, but I don't think they can. Also, don't they need a bigger mount for the IBIS? That sensor needs to move around in there.

The rebuttal shows images of an older Fuji camera and a big lens. Let's try putting the Fuji's 16mm f1.4 on a modern Fuji body and see how it looks... just saying.

Back to Hasselblad, I just thought they people should know the "pocketable" medium format camera isn't right around the corner- that's my point. :) 

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There may be many reasons why the Sont Lenses are Huge.

To begin with they resolve more pixels per sq cm of lens surface area. Canon's f2.8 lenses were unable to resolve the 50MP of their 5D S and R cameras and thus the f4 zoom was the recommended lens.

I am guessing the huge lens is because if is pushing the maximum possible detail into every single pixel.

I am guessing that for the same megapixel they would seem sharper than Canon and most likely Nikon too. 

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I think Sony lenses are gigantic for two reasons. Firstly lens designers have mainly been working with retrofocus designes for the last 60 years. Look at the otus line, even the 85mm is some sort of retrofocus design, it permits even illumination and resolution across the image, at the cost of complicated and large designs.

Obviously there is leica and the rest of rangefinder stuff, but here comes the second problem, digital sensors still need telecentricity, so this leaves us with large lenses for the time being. But this will change once the mirror becomes a thing of the past (unless the focal reducer approach is so good that it becomes the norm and this needs long register distances.

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17 hours ago, John Matthews said:

I just hope it doesn't run into this type of situation. Three FF cameras to scale: notice the mirrorless one has an enormous flange. I think it's just physics.

a7RIIvs5DsRvsa99_24-70mmf2.8-800x353.jpg

Petapixel had a whole article on this here:

http://petapixel.com/2016/04/04/sonys-full-frame-pro-mirrorless-fatal-mistake/

I have a feeling the reason the sony is so large is that it might be a re-purposed lens.  probably originally designed for a-mount, or at the very least designed to be onfigured to be used with a a-mount camera, and then the optical design has been translated into e-mount.  the additional 30mm length to make up for the lack of mirror.  

2 hours ago, Nikkor said:

I think Sony lenses are gigantic for two reasons. Firstly lens designers have mainly been working with retrofocus designes for the last 60 years. Look at the otus line, even the 85mm is some sort of retrofocus design, it permits even illumination and resolution across the image, at the cost of complicated and large designs.

Obviously there is leica and the rest of rangefinder stuff, but here comes the second problem, digital sensors still need telecentricity, so this leaves us with large lenses for the time being. But this will change once the mirror becomes a thing of the past (unless the focal reducer approach is so good that it becomes the norm and this needs long register distances.

yep.  micro lenses, cover glass etc.  all make shorter back focus distances a potential problem.  The Loxia lenses take leica style designs and apply correction for micro lenses and cover glass.

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