tupp

Not to mention the aberrations the adapter removes.

Can we just wish it into the cornfield?  LOL.  (Twilight Zone reference)

More pics and video please @Mattias Burling.

The DP's response would most likely be:  "Perhaps it would be better if you shot this yourself..."

Could you guys continue your cocksword fighting elsewhere? This is a thread dedicated to the kipon speedbooster review by mattias.

Yes. Except you miss the point again and again, which is a lens only works for it's intended image circle (and full look) on a certain size format... Thus if you like a lens that is designed for a FF format when used on FF, then it indeed has that "FF look" (as non-descriptive as that is). Your definitions are your definitions, whether you wish people used other terms or not is irrelevant, because they don't and is the reason you are in the perpetual argument now. (It's the same thing as me telling you that "look" is not the right word to describe equivalency, then you telling me that it is  .)

Its all down to taste I guess. Personally I have never owned a combo with creamier bokeh before. Not with 0.95 lenses, not M-Mounts, Sony FE, Canon-L or Nikon FX.
I just love how soft blurred edges get. How everything seems to flow into eachoter and how "un harsh" bokeh balls become without a bunch of specs in them. Just light.

This weekend Im finally shooting a video with the adapter.
Still haven't got all the stuff I wanted before I did it, like borrowing a A7sii etc, but I can't wait any longer. 
I must see how it looks
In other news,
I was interviewed by a local paper yesterday regarding my Instagram and accidentally said how much money that is just waiting for you in Swedish flee markets in the form of vintage lenses.
So I guess I will have some new competition, at least locally
Any who, the reporter wanted pictures of me taking street photos and I was carrying the A7 with adapter and 80mm f1.9.
So I did some more street shooting at f1.9 and its still very fun... and rather difficult.

 
Also today I opened the box to the very affordable Zeiss Jena 80mm f2.8 and the adapter can't get here fast enough.

I its anything like the earlier models of Zeiss Jenas Ive had I will be very happy.
Here is an old test with the 35mm in m42.
 
And a set of three C-Mounts.
 
So again, if the 80mm f2.8 only preforms half as good it will make for an interesting image.

I 2nd this!
@Mattias Burling
Also, could you do a DOF "equivalence" test between this set-up and your Digi-Bolex with a prime lens?
 
Thanks for showing these photos.  They look spectacular!

Beatles, move over...

when i first saw the trailer for la la land i could tell within seconds that it was shot on film, but who else can tell, other filmmakers?
certainly not the kids that watch this lana video on their iphones – i have to think any grainy look just reads as 'retro' to them
as much as i could criticize this video as looking a bit phony, on the positive side i think that the borderline 8mm extreme graininess is necessary to read as graininess on the itty bitty screen of that very same iphone
*I* waited to get home to watch this video on my tv to comment ?

You can rent/borrow a 77mm and/or 82mm filter(s) and just hold/tape it in front of your lens to check for vignetting.  Position it slightly forward to simulate two stacked filters with the added length of a step-up ring (and the extra millimeter or two from a polarizer).
 
You could also just buy/rent a big matte box with the same filters.

This has little to do with the adapter but since an A7 or Leica is mandatory for it to work.
And people still ask me about the A7 as a stills camera three years after my review of its video features.
I thought a quick review could be interesting to some.

There is some footage of the Kipon Reducer and samples at the end.
 

Ha!  I think I'll just suffer through the smaller formats.

Ha!  I think I'll just suffer through the smaller formats.

Ha!  I think I'll just suffer through the smaller formats.

Maybe worth getting back together with the ex

Its just our opinion Im not right nor wrong. Neither are you
For me 645 is to save film. 6x9 is for nice prints. 6x6 is for Square and pocketable.
6x7 is the odd APS-C. Smaller than my prefered 6x9 but not small enough to save film like the 645.
I dont think it being a macro have anything to do with it. Google "swirly bokeh". Its a very common characteristic in medium format lenses and many of my MF cameras has it.
So does alot of full frame lenses like the helios.

6x9 is obviously slightly wider than 6x7, but 645 is the APS-C.
This graphic shows it quite clearly:
https://upload.wikimedia.org/wikipedia/commons/e/ec/35mm_MF_LF_Comparison.svg

Don't know what is the widest MF lens that can fit on these adapters, but focal lengths as wide as 35mm were fairly common on MF, which is similar to having a 22mm lens on FF.
 
 
This is a excellent point, and diffraction can affect the focus, and, hence, the DOF roll-off.
 
 
Of course, the greater prevalence of diffraction with small formats is due to the physically smaller apertures of shorter focal length lenses -- not caused by the small sensor/film formats themselves.

The biggest advantage of moving to a larger format, even if it is film based or digital based, is Lens Diffraction, ergo the lack of it. The bigger you go film, sensor area wise the bigger you can go F stop wise or actually closed down. I know it is always ass backward.
That is why there was a F64 club back in the Ansel Adams, Weston days using 8 x 10 cameras. You can get tons of stuff in focus without distortion. Maybe not totally stopped down but damn close. That is the big problem with m4/3 it creeps in a f8 a lot and damn sure is at F11. So this Speed Booster could be damn interesting for that reason alone.

In addition to the suggestions above, you might consider a used camera:  the Digital Bolex; the Sony F3 (w/4:4:4 capability); the Sony FS700 (w/raw recorder); or a KiniMini refurb.
 
Also, I've heard good things about the DJI X5R.

De-clicking is definitely be beneficial if one shoots documentaries/events that often require the aperture to be ramped up/down during the shot (especially when using an on-camera mic).
 
I have a few vintage Nikkors, but I rarely ramp the aperture while rolling, so I haven't really needed to de-click.

Agreed.  Raw is great to have, but I've never really needed anything more than 10-bit, 4:4:4, flat and at a nice resolution.   A lot of the time, even that is overkill.

Again, nobody has yet done a conclusive, worthwhile "equivalence" test.
 
I don't mean to sound harsh (nor to hijack this thread), but the pages you linked either lack actual equivalence tests or give dubious, useless results.
 
The first page linked doesn't seem to contain any equivalence test -- it is just an essay titled "Sensor Crop Factors and Equivalence."  If there is an actual test of DOF equivalence on that page, please point it out.
 
The second page you linked actually contains a DOF equivalence test that seems to demonstrate that optics for larger sensors yield  quite a significant difference in DOF when compared to the DOF of to smaller optic.  So, it seems to demonstrate that the equivalence principle fails.  I spotted the differences immediately, and I will point to some of the more obvious discrepancies.  Here are the two images flashed back-to-back in a gif file:

The bottle in the foreground stays sharp in both images, but look at how the sharpness of the bush and car dramatically change (red circle).  Look at how the sharpness of the cast shadow and grass change (yellow circle).  Look at how the sharpness of the building changes (blue circle).
 
Does the DOF in these two flashing images seem equivalent?  It doesn't seem the same to me.
 
Now, I am not very good at making gif images, and I apologize for the rough dithering, but you can further confirm these differences yourself by downloading the two images from the linked site and switching back and forth between them in your favorite image viewer.  Actually, anyone should be able to see the difference inside the red circle, merely by viewing the two images on their web site.
 
On the other hand, I have to confess that this test is worthless.  In the first place, it appears that the tester failed to eliminate the variable of in-camera sharpening, so it is very possible that one camera sharpened its entire image while the other camera didn't.  More importantly, the tester put a lot of air between the foreground and the distant background.  Some of the "magic" of larger format optics happens in that air between the FG and BG, but this comparison has no objects nor charts in that air to reveal what is happening to the focus there.  This fatal blunder occurs in almost every equivalence test that I see.
 
The third link that you gave is the Brightland Studios test which has been referenced by me and others on this forum in several threads.  I am afraid that this is yet another misguided experiment in which the equivalence principle doesn't seem to hold up.
 
The tester made two comparisons using the same camera and zoom lens in both tests.  First he compared the equivalence between camera's full sensor read-out and the camera's crop mode:

With the front of the subject sharp in both images, the apparent counter top (red circle) in the distant background,changes focus, and does not appear to be equivalent in the two images.  Likewise, there is another detail in the distant background (blue circle) lacking equivalence of focus between the two test images.  There seems to be other subtle focus discrepancies, that I will mention later.
 
The tester acknowledged that the camera might apply a different degree of image processing/sharpening in full sensor mode than it would in crop mode, which could make the focus/DOF of the two test images seem more similar.  So, he made another comparison, in which he shot both images in full sensor mode, but one of the images was shot optically as if it was in crop mode.  That "simulated crop mode" photo was then cropped to matching size in post. Thus, in this second comparison, there was optical equivalence along with no difference in image processing/sharpening between the two shots:

As you can see, with the difference in in-camera processing eliminated, there are significant areas of non-equivalence. In addition to the counter top changing, the bokeh changes size and softness (red circle), while the front of the subject remains sharp.  The Canon logos conspicuously change their focus (blue circles) which happened more subtly in the first comparison, while the top buttons on the camera (yellow circle) do likewise.  Part of the tripod head (green circle) also conspicuously goes in and out of focus, and it does so more subtly in the first comparison.
 
So, the equivalence principle certainly seems to fail here, as well.
 
However, there are serious problems with this test.  For one thing he used the same zoom lens on all images.  Not only does the character of the lens look the same in each photo, but aperture position (virtual/actual) doesn't necessarily change with the zoom's set focal length.  So the zoom lens' aperture position probably doesn't match the differing aperture positions found on a prime lenses of the same focal length.  This discrepancy could make the DOF appear more uniform than if the test were done with separate prime lenses of different focal lengths.
 
Also, these Brightland Studios tests suffer from the same lack of any objects/charts in the important long stretch between the foreground subject and the distant background, so there is literally "nothing to see here."
 
The fourth and fifth links you provided seem to go to different pages of the same earlier thread concerning the Kipon MF focal reducer.  I am not sure what you expect me to find on these forum pages, but I do not see any equivalency tests.  By the way, on page two of that very thread, I address the Brightland Studios test in several posts.
 
I am hoping that one day someone will do a proper equivalency test with charts/objects placed at regular intervals extended behind the foreground.  Ideally, one camera would use a tiny format (2/3" or S16) while the other camera would be a large format (Gonzalo Ezcurra's Mini Cyclops, the LargeSense back, or a shift/stitch adapter).  Of course, a full frame camera with this Kipon focal reducer would be interesting to compare, too.