Jump to content

Kipon / Baveyes medium format speed booster for full frame Sony A7 series


Recommended Posts

Generally there are differences in the look of larger format DOF vs. smaller format DOF, even though their DOF range can be made technically equivalent.  I can see differences in the examples given in the link provided by jcs, even though the author of that page failed to provide images that were anywhere close to full res.  The discrepancies are more subtle when comparing images from formats which differ by a factor of only 1.5 (FF and S35), but the discrepancies often exist, nonetheless.   In digital, the main differences appear in how cleanly the DOF, focal plane and blur/bokeh are rendered.

 

To illustrate this point, let's consider two dramatically different format sizes -- ultra large format (11"x14") and S16.  This is an early test of Gonzalo Ezcurra's "Mini" Cyclops DOF adapter with a 14"-wide ground glass.  To me, the very shallow focal plane looks extremely clean and "solid" edge-to-edge, while the softer FG/BG blurs nicely and smoothly without abruptly going into complete mush.  I don't think that a S16 lens exists that can give the same clean/solid look in a shallow focal plane with such a smooth, gently soft BG/FG.

 

Just the same, one wonders about the potential of mounting the Kipon/Baveyes medium format focal reducer to a MetaBones BMPCC speed booster.  Can't wait to see the results of that combo!

 

Of course, when shooting a given film emulsion, the differences between format sizes are even more dramatic.  Larger formats have less grain, more resolution and more color depth.

Link to post
Share on other sites
  • Replies 67
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Popular Posts

This is exciting.  I highly doubt this unit will have optics of quality good enough to make investment in decent medium format glass worthwhile.  ie, even my Hasselblad 40mm/4, 50mm/2.8, 80mm/2.8 110m

Generally there are differences in the look of larger format DOF vs. smaller format DOF, even though their DOF range can be made technically equivalent.  I can see differences in the examples given in

I feel that these fell out of the buzz a bit, even now when they are out in the stores. And specially now when there is so much buzz around the Fuji MF camera. I mean who doesn't want Medium Fo

Posted Images

exactly.  though I interchange from true full frame or aps-c with a 0.7x speed booster and get very similar dof/fov with both, i'd always go full frame if I could.  the intricate step between in and out of focus is a lot more refined from a larger sensor.  If there wasn;t a benefit, pro's wouldnt be investing £25k+ in Phase1's and 80/2.8's.  they'd be shooting full frame and 50/1.2., closed down to f2.  Also, I wouldn't have spent money developing FORBES70, building a set of good quality MF glass,  I'd have grabbed fast modern 35mm lenses and spent the money on going on an expensive holiday. 

 

problem is, it's only the real pro's that realise that a MF 80/2.8 wide open has more refined defocus rolloff, and better overall performance than the canon 50mm L closed down by 2 whole stops! And the real pro's don;t have time to enter into this debate - their too busy shooting.  

 

Roll up to shoot a automotive commercial with a 5dsr instead of a medium format setup and you'll be turned home by the creative director.

 

 

Link to post
Share on other sites

I did the tests between S35 and FF in the link I provided earlier. I challenge anyone to try the same tests comparing FF to MF and post the results online to let people try see the differences themselves (without telling them which is which at first).

I have been tempted to get into a Phase One camera system, not for any special MF look (since it doesn't exist), but rather their advanced sensor: 80Mpix, 16-bit, 14 stops DR, updated autofocus, and very cool touchscreen camera interface: https://www.phaseone.com/en/Products/Camera-Systems/XF-Camera-System.aspx (a major investment at $49K, though if one is booking $10K and up advertising gigs, that's not a lot of money).

If one only needs 50Mpix, the Canon 5DS is pretty solid, for way less investment. Top photographer Peter Hurley went from Hasselblad, to Phase One, to Canon 5DS: http://www.slrlounge.com/peter-hurley-shows-us-whats-in-his-bag/ (granted he might be privately shooting with Hasselblad (body) and/or Phase One (body and/or digital back) in his studio, he's outwardly stating the 5DS as his current camera system (perhaps paid by Canon)).

Link to post
Share on other sites
Guest Ebrahim Saadawi

here we go again *starts shaking in fear*

wait. please... im begging you. im freaking out rn. not being ironic here: > does this mean theoretical lenses which dont exist? with wider apertures than they normally have? talk to me like im 4 years old. i feel like i get this if it means, If lenses on my 35mm ff camera had wider apertures, they could give a medium format look for their respective fields of view 

again, please help me understand this. why is this so confusing to me?? ive shot medium format film but it was a looong time ago. today i feel like i have a pretty strong handle of sensor size in relation to depth of field in practice, and maybe this is a more theoretical discussion? like an "all things being equal" comparison??

crying rn bc i feel so dumb ? 

Not dumb at all, yes all your conclusions are correct. 

To simplify,  50mm F/2 lens on FF is a look. A field of view and a depth of field. 

You have a m43s (2x crop) size sensor and want the same look, 

you use a 25mm f/1 lens. you will get the same field of view and depth of field. 

If you have a much larger sensor than FF, with a 0.5x crop factor. 

Then, you'll get the same look by using a 100mm f/4 lens. 

And so on. 

The difference in resolution, DR, colour science, lowlight performance of these sensors are a different matter, but have no rules, as smaller sensors outperform larger ones and vice verse. Also the quality of these different three lenses are irrelevant as they are variable and the m43s 25mm might be better than that certain 50mm or vice versa. 

 

Lets talk medium format. In history, people shoot medium format not just because of the awesome background separation for portraiture but also for the very high resolution (30-50mp) and for the colour depth (14-16bit raw) they offer. This made a medium format camera give an image that's simply unachievable by a FF camera. It doesn't have the resolution or DR or colour depth. 

The most common type of use for medium format is landscape photography, just due to the huge resolution and unparalleled ability to print at larger fine detail. This is THE characteristic MF look, very high detail reproduction.

But now, The Nikon D810 FF sensor has a medium format quality resolution, exceeds MF Dynamic range, and has extraordinary colour depth. Same goes with the Canon 5Ds sensor, and Sony A7rII, You can get these extraordinary high resolution and depth landscapes from these FF cameras.

The variable left is the depth of field.

Medium format lenses rarely have wider aperture than f2.8,

so FF lenses with 1.2/1.4 give the same of shallower look.

But there's a thing which is medium format lenses are of very high quality and are sharp at f/2.8 while most FF 1.2/1.4 lenses are soft at these apertures. This gave medium format an advantage in getting shallow DOF-yet-sharp images.

But again this is highly variable and many MF lenses perform badly at f/2.8 also, and there are FF lenses with MF-quality at maximum 1.4 apertures (Zeiss Otus 50/85mm f/1.4, Canon 35mm f/1.4 II, Sigma 50mm f/1.4, etc) 

So in brief the FF system just kept evolving very fast until it reached medium format images in quality and look. If you have a Sony A7r II, Canon 5DsR, Nikon D810, coupled with a Zeis Otus 50mm f/1.4, you have a system capable of producing the same or better images than many MF systems, in resolution, dynamic range, lowlight performance, depth of field, colour depth, etc. The gap is shrinking, and it will keep shrinking. 

Link to post
Share on other sites

I challenge anyone to try the same tests comparing FF to MF and post the results online to let people try see the differences themselves (without telling them which is which at first).

I would like to see such a test, too.

 

However, why limit the test to two formats with close crop factors?  If there is absolutely no difference in the DOF of different formats and if we can exactly match the DOF look between any two formats, then why don't we compare two dramatically different format sizes, such as s16 and 11"x14"?

 

If what you say is true, we should be able to match the DOF look exactly between two such vastly different format sizes.

 

To simplify,  50mm F/2 lens on FF is a look. A field of view and a depth of field. You have a m43s (2x crop) size sensor and want the same look, you use a 25mm f/1 lens. you will get the same field of view and depth of field.  If you have a much larger sensor than FF, with a 0.5x crop factor.  Then, you'll get the same look by using a 100mm f/4 lens.

I disagree.  The DOF "range" might be technically equivalent, but it will look different in how the DOF rolls off and in the softness of the out of focus areas.  Also, the flatness and sharpness of the focal plane will probably be different.

 

Lets talk medium format. In history, people shoot medium format not just because of the awesome background separation for portraiture but also for the very high resolution (30-50mp) and for the colour depth (14-16bit raw) they offer.

Wait -- is there or is there not difference in formats in regards to DOF and background separation?

 

Also, the format size doesn't really have anything to do with bit depth.  I assume you are referring to what has happened historically.

 

Furthermore, bit depth is not color depth -- bit depth is merely one factor of digital color depth, and resolution is an equivalent factor of color depth (in both digital and analog).

 

This made a medium format camera give an image that's simply unachievable by a FF camera. It doesn't have the resolution or DR or colour depth.

If anything, the dynamic range of sensors has much more to do with photosite size than it has to do with sensor size, but there certainly are other variables that significantly influence dynamic range.

 

Color depth in digital mainly involves bit depth and resolution.  Format size in digital is irrelevant color depth (unless it influences resolution).

 

But now, The Nikon D810 FF sensor has a medium format quality resolution, exceeds MF Dynamic range, and has extraordinary colour depth.

Again, dynamic range has more to do with photosite size than it does with format size.  Color depth in digital is determined by the resolution and bit depth.

 

But there's a thing which is medium format lenses are of very high quality and are sharp at f/2.8 while most FF 1.2/1.4 lenses are soft at these apertures. This gave medium format an advantage in getting shallow DOF-yet-sharp images.

Agreed.  That is one of the advantages we've mentioned of using lenses for larger formats that have longer focal lengths.  The focal plane is sharp and flat.

Link to post
Share on other sites

I would like to see such a test, too.

However, why limit the test to two formats with close crop factors?  If there is absolutely no difference in the DOF of different formats and if we can exactly match the DOF look between any two formats, then why don't we compare two dramatically different format sizes, such as s16 and 11"x14"?

If what you say is true, we should be able to match the DOF look exactly between two such vastly different format sizes.

Go for it if you have access to S16 and 11"x14"! Most people are curious to see if it's worth moving up from one format to another. Currently the A7RII and 5DS/r are contenders to compete with MF systems, so comparing FF to MF would be helpful.

Remember, this test can also be done with just one camera, and cropping in post (after changing camera settings).  Thus anyone can do this test with any camera if they want the truth. Here's how I did it: http://brightland.com/w/the-full-frame-look-is-a-myth-heres-how-to-prove-it-for-yourself/ , and here's the math and physics: http://www.josephjamesphotography.com/equivalence/ .

Link to post
Share on other sites

Go for it if you have access to S16 and 11"x14"! Most people are curious to see if it's worth moving up from one format to another. Currently the A7RII and 5DS/r are contenders to compete with MF systems, so comparing FF to MF would be helpful.

I don't even have FF nor MF.

 

However, if you claim that there is absolutely no focus/DOF difference between formats and their respective lenses, then the look should be exactly the same between s16 and 11"x14".

 

Do you think that a test between to such different format sizes would show no difference in focus/DOF look?

 

Remember, this test can also be done with just one camera, and cropping in post (after changing camera settings).

Primes of different focal lengths should be used, as the focal point and aperture distance will not change when using the same zoom lens for both formats.

 

I applaud you for taking the time and effort to make the comparison.  Very few folks have the gumption to initiate and publish such tests.

 

However, by using the same zoom lens on both images, you are essentially (and actually) using the same lens with the same look (and with the same focal point and aperture distance).  Such would not be the case when comparing MF to other formats.

 

Also, it is important in such tests to place objects in the frame at short and regular distance intervals from foreground to background.  It is difficult to tell much from showing just one foreground object against a distant background (while using the same zoom lens on all images).

 

... and here's the math and physics: http://www.josephjamesphotography.com/equivalence/ .

Thanks for the link.  I dealt with DOF calculations in photo classes, and it seems that he essentially is just adding the crop factor to that formula.

 

I didn't read the entire page, but I think that he is just saying that the DOF range can be equivalent -- he does not seem to claim that the look of the focus/DOF is equivalent regardless of focal length and optical quality.

 

He even mentions that larger formats almost always have larger aperture diameters (in mm) for a given angle of view (with a given DOF).  I think this difference is a significant advantage for larger formats, along with the fact that one can use narrower f-stops on larger formats (to get a sharper focal plane) than a smaller format using a wider f-stop to get technically equivalent DOF.

Link to post
Share on other sites

I think a factor is that it's easier to make a good 80mm f/2.8 for a 645er format than a 50mm f/2 for 35mm than a 25mm f/1 for MicroFourThird. So chances are that the corners are sharper, there's less chromatic aberrations, etc. While you will be able to match DoF, FoV, etc. you will still get a different image in the end and 99.5% of people see no difference. I've shot with the Canon 85mm f/1.2L on 35mm and was blown away by it but mostly everyone I know couldn't see any difference to a Sigma 85 1.4 or Canon 85 1.8.

So far I've shot m43, APS-C, digital & analog 35mm and analog 645. I think the specific look has more to do with the lens than with the camera system. Obviously MediumFormat offers also leaf shutter lenses which can be a huge benefit against focal plane shutters when shooting with strobes as you can synch flash at any shutter speed, on the other hand focal plane shutters on modern cameras have far quicker speeds available. Horses for courses.

 

Personally I think I couldn't tell in a blind test.

Link to post
Share on other sites

Kinda curious as to where there hasn't yet been a MF to DSLR mount (EF or F mount) focal reducer.
I'd love to use my Pentax 645 on my Nikon DSLRs (already have a dumb adapter), and then use them with a double focal reducer of Pentax 645 to Nikon F to m4/3 adapters! ;-) ha

unfortunately the focal reducer element would protrude too deep into the body and would cause mirror problems.

Link to post
Share on other sites

Surprised no one has mentioned the fastest (and cheapest) MF lens, the Mamiya 80mm f/1.9, known as the Nocilux for Medium Format. It's sharp with lovely characteristic Bokeh. I use the 110mm f/2.8 also, gorgeous glass. IMG_0774.thumb.JPG.d1f13f5d6bc42ba1ab32d

 

I've shot some anamorphic footage also as a taking lens, the image is killer! 

Yes, the Hasselblads are optimal performers but I find the image less interesting on some versions but that's just me, I love that vintage look. And if we're talking bang-for-buck, nothing touches Mamiya - 200€ for the fastest MF ever made for mass production. Expect that price to go North if Kipon make a Mamiya mount, i'll be getting one for sure.

A7rII/sII with this Kipon speed booster and the 80mm f/1.9 Sekor C? *drool*

Link to post
Share on other sites

I don't want to ruin the dream but I doubt the adapter is that bright. My guess is that the diameter is not larger than f/1.4. 

What does that even mean? Anyway, it's not true, no worries, the 80 1.9 isn't a strange lens, entrance and exit pupil look the same as on the nikkor 50 1.2 to me (I have them right here in front of me). If there is a problem it will be with long lenses but that would be the same with the other speedboosters and I haven't heard anybody complain yet.

 

Link to post
Share on other sites

What does that even mean? Anyway, it's not true, no worries, the 80 1.9 isn't a strange lens, entrance and exit pupil look the same as on the nikkor 50 1.2 to me (I have them right here in front of me). If there is a problem it will be with long lenses but that would be the same with the other speedboosters and I haven't heard anybody complain yet.

Its not about what is possible, but more what the specific adapter is capable of. We still have to wait, but judging from the picture of the adapter the entrance diameter of the glass looks about the size of the 50 1.4. I expect the exit diameter to be even less. 

But that's based on an image without knowing the actual size or optical design...

So yeah f/1.2 could still be the case. 

Link to post
Share on other sites

Surprised no one has mentioned the fastest (and cheapest) MF lens, the Mamiya 80mm f/1.9, known as the Nocilux for Medium Format. It's sharp with lovely characteristic Bokeh. I use the 110mm f/2.8 also, gorgeous glass. IMG_0774.thumb.JPG.d1f13f5d6bc42ba1ab32d

 

I've shot some anamorphic footage also as a taking lens, the image is killer! 

Yes, the Hasselblads are optimal performers but I find the image less interesting on some versions but that's just me, I love that vintage look. And if we're talking bang-for-buck, nothing touches Mamiya - 200€ for the fastest MF ever made for mass production. Expect that price to go North if Kipon make a Mamiya mount, i'll be getting one for sure.

A7rII/sII with this Kipon speed booster and the 80mm f/1.9 Sekor C? *drool*

The fastest? Not really... I've got a whole bunch of faster ones sitting here.

Here's a complete list of fast medium format lenses:

Fairchild 75mm F/1.9
Zeiss 125mm F/1.5 Sonnar
Zeiss 85mm F/1.4 Planar
Ernostar 85mm F/1.8
Ernostar 125mm F/1.8
Aerojet Delft 64mm F/1.8 
Aerojet Delft 70mm F/1.6 
Aerojet Delft 75mm F/1.7
Aerojet Delft 100mm F/1.4
Aerojet Delft 112mm F/1.4 
Aerojet Delft 150mm F/1.5
Aerojet Delft 300mm F/1.5
Delft Rayxar 105mm F/0.75
Delft Rayxar 150mm F/0.75
Delft Rayxar 250mm F/0.75
Perkin Elmer 75mm F/1.5 
Perkin Elmer 150mm F/1.5
Perkin Elmer 300mm F/1.5
Wild Heerbrugg 98m F/1.4 
Wild Heerbrugg 98mm F/1.0
Wild Heerbrugg 250mm F/1.8
Farrand Optical Super Farron 150mm f/0.87

Leitz Elcan 100mm F/1.4
Mamiya 80mm F/1.9
TTH 100mm F/1.8

 

veocr5.jpg

Link to post
Share on other sites

You can't use that last lens because it has a very short flange focal distance (as said on mflenses.com). There are a lot of fast short teles that could cover 645, but most of them have the same problem.

You mean the Delft 112mm f/1.4? The back focal flange distance is 56mm on that lens.

The Rayxar 150mm f/0.75 does have a very short back focal distance of only about 7mm

https://archive.org/stream/USAF_lens_datasheets/03-Section-2-part-2#page/n9/mode/2u

 

1.jpg

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...