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Metabones + Pocket 4K

PostPosted: Wed Sep 12, 2018 2:25 pm
by Janis Lionel
Hi there,

I know this has come up various times - still I'm not quite sure which version (Speedbooster) will work for the Pocket 4K and Canon EF. I don't wanna spend the money falsly. The 600$ already seem kind of ridiculous next to that cheap, beasty camera.

This one: https://www.bhphotovideo.com/c/product/ ... 4_3_t.html

Or this one: https://www.bhphotovideo.com/c/product/ ... 4_3_t.html

Thanks for the clarification.

Cheers

Re: Metabones + Pocket 4K

PostPosted: Wed Sep 12, 2018 3:21 pm
by Sean van Berlo
Both work, however the 0.64x only works with full-frame lenses (but gives you a larger magnification and more light) whereas the 0.71x also works with aps-lenses.

I would also highly suggest you look at the Viltrox 0.71x, as most people say the image quality is excellent and it costs about 1/5th of the Metabones. I know I will be comparing the two.

Re: Metabones + Pocket 4K

PostPosted: Wed Sep 12, 2018 4:55 pm
by Ryan Humphrey
Sean van Berlo wrote:I would also highly suggest you look at the Viltrox 0.71x, as most people say the image quality is excellent and it costs about 1/5th of the Metabones. I know I will be comparing the two.

I've always been a little baffled by the lack or rigorous comparisons of the various focal reducers that are out there. If you go looking for comparisons, what you find are generally years/several product version old, or done by people with direct connection to one of the products being tested. There's lots of "Everyone knows such-and-such" and "I've heard that..." statements and very little hard comparisons.

Always baffled me a bit. Every few months a new shootout or testing of some new ND filter or what have you gets done, but almost nothing rigorous for these kinds of lens adapters.

Re: Metabones + Pocket 4K

PostPosted: Wed Sep 12, 2018 5:36 pm
by Denny Smith
I always support the outfit the developed the product to start with, and actually owns the design or tech inside, rather than someone else’s copy. In this case Metabones, with a proven track record in making high quality adapters are precision made, and will hold up to rigorous use.
Cheers

Re: Metabones + Pocket 4K

PostPosted: Thu Sep 13, 2018 5:45 am
by DavidNJ
I am confused here.

Why would you get the Gen4 adapter instead of the newer Gen5 which includes locking lens mount?

Beyond the simple improvements to operation brought by new programming and the high-speed 32-bit processor, these fifth-generation adapters now feature rubber gaskets to protect the camera mount from dust and moisture entering, an LED light to show users the adapter’s current mode or status, and a dedicated switch that will control the in-body image stabilization of select Sony cameras. Also, the CINE models sport a positive-lock lens mount that holds your larger and heavier lenses more securely.

Metabones + Pocket 4K

PostPosted: Thu Sep 13, 2018 4:42 pm
by rick.lang
Sean van Berlo wrote:Both work, however the 0.64x only works with full-frame lenses (but gives you a larger magnification and more light) whereas the 0.71x also works with aps-lenses...


Sean, there may be some confusion on the suitability of the focal reducers using the wider dimension of sensor on the BMPCC4K. People’s impressions of the focal reducers’s suitable taking lens may have been formed by their use on the BMCC or original BMPCC. But those sensors are significantly smaller. Here’s the current math normalized to the horizontal ‘crop factor’ which does come in handy for such quick comparisons. Comparing the sensor diagonal would be a little more accurate, but I don’t think the results differ.

mFT lenses suit cameras with a sensor crop factor around 2x crop
APS-C EF-S lenses are designed for sensors with a crop factor of about 1.6x
APS-C DX lenses are designed for sensors with a crop factor of about 1.53x
Super 35 lenses are designed for sensors with a crop factor of 1.44x
APS-H lenses suit cameras with a sensor crop factor around 1.2-1.3x (I forget).

URSA Mini 4.6K sensor has a crop of about 1.42x
Super 35 24.9mm sensor has a crop about 1.45x
BMPCC4K 18.96mm sensor has a crop of 1.9x
mFT traditional camera’s 17.3mm crop is 2.08x
BMCC has a crop of 2.28x
BMPCC has a crop of 2.88x

Ultra 0.71x reducer shooting open gate:
1.9x0.71x = 1.35x full frame (or APS-H) required
2.08x0.71x = 1.48x Super 35 or greater work
2.28x0.71x = 1.62x APS-C or greater
2.88x0.71x = 2.04x APS-C or greater

XL 0.64x reducer shooting open gate:
1.9x0.64x = 1.22x full frame required
2.08x0.64x = 1.33x full frame (or APS-H) required
2.28x0.64x = 1.46x Super 35 or greater
2.88x0.64x = 1.84x so APS-C or greater

0.5x reducer (modify Pentax version):
1.9x0.5x = 0.95x VistaVision required;
some full frame may work such as Zeiss CP2/CP3 and SLR Magic APO.

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Re: Metabones + Pocket 4K

PostPosted: Thu Sep 13, 2018 4:46 pm
by Denny Smith
Nice Rick, but it is the camera, and not the lens that has a crop factor. ;)
So MFT lenses do not have a crop factor, the cameras do, with the GH4/5 having the greatest, more than 2X, and the GH5/s and BMPCC 4K having the least around 1.9, as you later point out. Thanks for putting this together, gives a nice quick overview in one place.
Cheers

Re: Metabones + Pocket 4K

PostPosted: Fri Sep 14, 2018 7:51 pm
by rick.lang
I’ll reword that post; check it out in a few minutes.


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Re: Metabones + Pocket 4K

PostPosted: Wed Nov 07, 2018 1:56 pm
by Janis Lionel
Yay, I will get my Pocket! Now, even though Rick (thanks for that) has flawlessly listed the differences between the Ultra and XL. I - so far - only have full frame lenses, though I mostly shoot in the tele-range, which would speek for the Ultra with 0.71. Though the XL gives me a little more light.

Has anybody had the chance to test them both? Are there any quality differences? I guess AF doesn't work on both of them so far yet?

Thanks for the feedback.

Re: Metabones + Pocket 4K

PostPosted: Wed Nov 07, 2018 5:18 pm
by Robert Niessner
I've the Metabones Cine 0.71 Ultra and it works great with my lenses, except for AF - that does not work currently. The cool thing about the Cine is the positive lock. I have put the PCC4k into a 8sinn half cage and added their universal rod support and lens support to secure the Metabones adapter. Now lenses are sitting rock solid on the camera, even my heavy Tokina Cine 50-135 T2.8 sits nice on this combination.

Re: Metabones + Pocket 4K

PostPosted: Wed Nov 07, 2018 8:50 pm
by rick.lang
Janis, can think of two factors that come into play when considering Metabones SpeedBooster Ultra versus XL. But they’re a trade off potentially. Let’s assume the change in apparent focal lengths and aperture are not relevant, that both apertures and focal lengths are suited to your purpose. And let’s assume both SpeedBoosters are optically perfect.

First, the line pair resolving power of your lens is increased using a focal reducer. So more true detail will appear in your image especially when using a higher resolution sensor. So that’s score one for the XL.

Second, the wider your angle of view becomes, the closer you are getting to the edge of the image circle. Typically lenses are closer to perfect about the centre of the focus/frame. As you move away from the centre, some smooth degradation may be apparent. Somewhere nearer the edge and often in the corner, the image is noticeably degraded, perhaps with an overall softness or with chromatic aberration. The Ultra tends to keep you closer to the sharpest area and so score one for the Ultra in most situations.

If you have a telecentric lens, your image will tend to look better from edge to edge, but these are not the typical lens design for budget lenses. So the more central area of the frame can be referred to as the sweet spot where your image looks best, just like keeping your iris around T2.8-T5.6 is the sweet spot for the lens. A telecentric lens and a XL may be the best combination for those who can afford those lenses.


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Re: Metabones + Pocket 4K

PostPosted: Thu Nov 08, 2018 6:43 pm
by Denny Smith
Also, the Ultra at 0.71 gives more useable standard focal lengths. Standard epS35 equivalent Video focal lengths for MFT (16:9) are 14, 17.5, 25, 42 and 50mm, with the later two your portrait focal lengths.

So the 0.71 SB gives 17.5 from a 28mm (like the Zeiss 28mm f/2) 25mm from a 35mm, 42mm from a 60mm, etc. Do the math with your favorite focal,eights to see which one works better, given yiu are using FF 135mm lenses, and not APC/DX lenses, which restricts yiu to the Ultra.
Cheers

Re: Metabones + Pocket 4K

PostPosted: Thu Nov 15, 2018 11:39 am
by Janis Lionel
Thanks for the replies.

Now I would really appreciate an input from somebody using the 0.64 in real life and what their experience is so far :-) If I'm correct the XL was concepted for the GH4/5 with x 2 crop instead of the pockets 1.9x crop.

Cheers

Re: Metabones + Pocket 4K

PostPosted: Thu Nov 15, 2018 1:43 pm
by rick.lang



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Re: Metabones + Pocket 4K

PostPosted: Thu Nov 15, 2018 3:13 pm
by JoshMallett
I own the XL 0.64 Metabones Speedbooster and used it on my GH4 which was a plus when moving to the CMPCC 4k...that I already own a Speedbooster and won't have to make that extra $650 investment. I just got my Pocket Cam 4k on Tues so haven't been out in the field yet, but Upon a quick test in my basement...it worked well minus the vignetting that appeared at wide angle focal lengths (it was very apparently pulled wide out on my Sigma 17-50mm...but that's a given with the information given above.) But I have yet to really do in depth field testing and I'm in no rush, tbh. I know imma get reamed by those on here still waiting for their pocket cam 4k....but I kinda just put mine in it's travel bag and it's Sat there since as it serves as only a B-cam to me. I'm going to head home in a little bit and tinker with it more, tho, and I have
a shooter later today..

Re: Metabones + Pocket 4K

PostPosted: Thu Nov 15, 2018 5:21 pm
by Fran Tormo
Hi everybody!
I already bought ( but I still don´t have it ) a Bmpcc 4K
I want to use it with my URSA Mini pro and share between them the new set of SLR APO hyper primes
We had the PL to EF adapter for the APO primes, so we can use Metabones EF for fast sharing lenses
Wich metabones speed booster would get closer to the URSA mini pro? Ultra XL?
Thanks a lot

Re: Metabones + Pocket 4K

PostPosted: Thu Nov 15, 2018 5:32 pm
by Denny Smith
Fran, the U,tea, with its 0.71 factor,mis the one that takes a MFT sensor to a very close field of view of the S35 sensor Cine Cameras. How close, will depend on which gate you are using on the UM 4.6 sensor and the Pocket 4K, full gate will be a little wider, UHD gate/crop will be very close. Neither will be an exact match, but rhe Ultra I feel is closer, having used this one on the AF100 to match S35 AOVs.

Metabones + Pocket 4K

PostPosted: Thu Nov 15, 2018 6:08 pm
by rick.lang
Fran, congratulations on the set of SLR Magic APO primes. If you have not purchased a Metabones SpeedBooster and you are crazy about shooting with PL glass, you might consider the MFT-PL SpeedBooster. That way you’ll have a better chance of minimizing any play in the lens as you rotate the lens gears. Did you also buy the passive MFT-PL adapter from SLR Magic? I’ve preordered it, but not received it yet. I’d recommend it.

Let us know how things go with whichever SpeedBooster you get, but at this point I’m deferring the purchase of a SpeedBooster until 2019 as I’m bringing in some other toys to play with.

Denny’s advice is sound.



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Re: Metabones + Pocket 4K

PostPosted: Thu Nov 15, 2018 8:12 pm
by Fran Tormo
Thanks a lot Denny and Rick!
Well, still don´t have the bmpcc 4k in my hands, but most of the work is in EF with the URSA MP, so make sense go the EF route instead PL. We got the passive adapters EF-PL from SLR magic for the Ursa MP, so once we get the speed booster MFT-EF Ultra 0.71 we will be set up
I have to say that the APO´s are very very nice! We are waiting for the 32mm.
We made recently a work and we are very very impressed, loving the cinematic feeling, very robust, not so heavy, so we can use them with URSa mini pro, A7sJJ or whatever...
Hope to share soon this work

Re: Metabones + Pocket 4K

PostPosted: Thu Nov 15, 2018 9:29 pm
by Rustam Babayev
Image

Re: Metabones + Pocket 4K

PostPosted: Fri Nov 16, 2018 2:41 am
by rick.lang
Nice graphic, Rustam. Your numbers look good.


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Re: Metabones + Pocket 4K

PostPosted: Fri Nov 16, 2018 3:28 am
by Denny Smith
On,y thing missing is the Ursa Mini sensor gate size for a reference.
Cheers

Re: Metabones + Pocket 4K

PostPosted: Fri Nov 16, 2018 4:08 am
by rick.lang
With a horizontal crop of 1.42x, the URSA Mini 4.6K falls just a little inside the outer green area. As you were recommending the SpeedBooster Ultra on the BMPCC4K is most similar to the Mini 4.6K.


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Re: Metabones + Pocket 4K

PostPosted: Fri Nov 16, 2018 6:20 am
by Denny Smith
Thanks Rick, that is what I thought.
Cheers

Re: Metabones + Pocket 4K

PostPosted: Fri Nov 16, 2018 3:15 pm
by John Richard

Re: Metabones + Pocket 4K

PostPosted: Sat Nov 17, 2018 9:05 pm
by Janis Lionel
I got the 0.71 even though i only have full frame lenses.

Re: Metabones + Pocket 4K

PostPosted: Sun Nov 18, 2018 1:01 am
by rick.lang
That’s what I would do as well. That’s will get you as wide or wider than the angle of view of the URSA Mini 4.6K sensor and you’re using the best part of the full frame lens.

Re: Metabones + Pocket 4K

PostPosted: Sun Nov 25, 2018 8:43 am
by dondidnod
I use an Aputure DEC Lensregain Wireless Remote Adapter on my BMPCC 4K and it works with my EF-S Canon 18-55mm f/3.5-5.6 IS STM "kit" lens, my Canon EF-S 70-200mm f/4-5.6 IS STM lens and my Canon 20-35mm f/2.8L EF lens in window mode. The wireless transmitter supplies power to the image stabilization which works fine. It has a .75 focal reducer lens and provides wireless control of the iris and focus with 2 stops you can set and variable focus speed. The lanc control doesn't plug into the camera so there is no remote start and stop however.
Although I have no experience using a Metabones Speedbooster, several people on the internet say the Lensregain's quality is on a par with it. It should be noted however that there is no electrical connection with the BMPCC 4K, so the autofocus and the iris control of the lens from the camera doesn't work.
The Canon 18-55mm f/3.5-5.6 IS STM lens can be found on Ebay for about the cost of a quality UV filter.
Best of all B & H has it on sale for $150, half the price of what I paid for it used. Being a compact unit, I intend to use it with a gimbal.

Re: Metabones + Pocket 4K

PostPosted: Thu Nov 29, 2018 7:37 pm
by dondidnod
Update on the Aputure DEC Lensregain. I just received a SmallRig Metabones Adapter Support for BMPCC 4K 2247 to provide support for the Lensregain on the Smallrig full cage. It worked fine. I also got the mount for the Samsung T5 to work on the second try after installing the Lensregain transmitter first. The first time there was no signal to the camera because the transmitter was too close to the T5 mount. I will order the remote cable to place the transmitter away so it doesn't ruin the socket.
I also tried a Canon EF-S 10–18mm f/4.5–5.6 IS STM lens and it worked. In addition, I tried a Canon EF-S 24mm f/2.8 STM lens but found that a hard rubber doughnut has a tight fit against the Lensregain and there is no exposure control or IS on this lens

Re: Metabones + Pocket 4K

PostPosted: Sat Dec 08, 2018 5:34 am
by aglyons
Can anyone answer this?

Just got my 4K with a meta .71 Nikon. I've got my 14-24 on there and I noticed in the menu that the window sensor with was on but greyed out.

Does that mean the meta is kicking in the window mode for some reason?

I was shooting 4k not HD in case it was a question.

Re: Metabones + Pocket 4K

PostPosted: Thu Dec 20, 2018 7:26 pm
by tr3ska
Robert Niessner wrote:I've the Metabones Cine 0.71 Ultra and it works great with my lenses, except for AF - that does not work currently. The cool thing about the Cine is the positive lock. I have put the PCC4k into a 8sinn half cage and added their universal rod support and lens support to secure the Metabones adapter. Now lenses are sitting rock solid on the camera, even my heavy Tokina Cine 50-135 T2.8 sits nice on this combination.


Hey Robert,

I’m planning to buy the tokina 50-135 cine ef and also the metabones speedbooster cine 0.71 ef to mft. I’m wondering if the focus changes on this configuration when zooming?

Thanks so much for your response.

Re: Metabones + Pocket 4K

PostPosted: Fri Dec 21, 2018 12:43 am
by rick.lang
aglyons wrote:... I was shooting 4k not HD in case it was a question.


Were you shooting 4096x2160 or 3840x2160? Shooting raw or ProRes?


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Re: Metabones + Pocket 4K

PostPosted: Fri Dec 21, 2018 1:27 am
by Robert Niessner
tr3ska wrote:
Robert Niessner wrote:I've the Metabones Cine 0.71 Ultra and it works great with my lenses, except for AF - that does not work currently. The cool thing about the Cine is the positive lock. I have put the PCC4k into a 8sinn half cage and added their universal rod support and lens support to secure the Metabones adapter. Now lenses are sitting rock solid on the camera, even my heavy Tokina Cine 50-135 T2.8 sits nice on this combination.


Hey Robert,

I’m planning to buy the tokina 50-135 cine ef and also the metabones speedbooster cine 0.71 ef to mft. I’m wondering if the focus changes on this configuration when zooming?

Thanks so much for your response.


Haven't used the 50-135 much with my PCC4k but as far as I remember it holds focus in this configuration.

Re: Metabones + Pocket 4K

PostPosted: Sun Dec 23, 2018 8:55 pm
by vgs2003
tr3ska wrote:Hey Robert,

I’m planning to buy the tokina 50-135 cine ef and also the metabones speedbooster cine 0.71 ef to mft. I’m wondering if the focus changes on this configuration when zooming?

Thanks so much for your response.


I am not Robert, but I do own that configuration and can confirm that it does not change it's focus while zooming.

Re: Metabones + Pocket 4K

PostPosted: Thu Feb 14, 2019 8:03 pm
by aaronboys89
Here is some test footage of the Metabones with the Pocket 4K. He is comparing the Metabones to the Viltrox on the Pocket 4K, and he gives a quick visual comparison of the Ultra vs the XL!

Search Youtube: Which Speedbooster for Blackmagic Pocket 4K ? Viltrox vs Metabones 0.71x compared !

I cant post URLS apparently.

Re: Metabones + Pocket 4K

PostPosted: Thu Feb 14, 2019 9:34 pm
by Robert Niessner
You mean that video by Zebra Zone:

Re: Metabones + Pocket 4K

PostPosted: Thu Feb 14, 2019 10:27 pm
by rick.lang
That is such a good review. Enjoyable and informative and proves “a picture is worth a thousand words.”


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Re: Metabones + Pocket 4K

PostPosted: Fri Feb 15, 2019 12:55 am
by Adam Silver
I agree with Rick. That was an excellent video.

Adam

Re: Metabones + Pocket 4K

PostPosted: Mon Feb 18, 2019 11:13 am
by Chris_T-Bay
Great explanation of the image circle in the video. I started with a Viltrox M1 without glass inside and my APS-C lens, after I realized that I couldn't use my 0.58 MB speedbooster anymore (besides in window sensor mode). When I can afford a speedbooster again I will go for the Metabones...

Re: Metabones + Pocket 4K

PostPosted: Mon Feb 18, 2019 5:02 pm
by dondidnod
BH has the DEC Lensregain wireless EF to M43 focal reducer on sale for $199.

Re: Metabones + Pocket 4K

PostPosted: Mon Feb 18, 2019 5:44 pm
by michaeldhead
dondidnod wrote:BH has the DEC Lensregain wireless EF to M43 focal reducer on sale for $199.


I have this and so far it's been super solid on the P4k - although I end up mostly using manual primes and a follow focus instead of using the Lensregain's lens control.

I used this setup on this video:


Re: Metabones + Pocket 4K

PostPosted: Mon Feb 18, 2019 6:42 pm
by Rado Stefanov
I got the Metabones canon adapter only for my Sigma 18-35mm and 50-100mm and the infinity focus is off by a lot. Without the glass is there a way to fix that?

Re: Metabones + Pocket 4K

PostPosted: Mon Feb 18, 2019 8:03 pm
by dondidnod
Michael, Nice professional looking short. Remarkable bokeh for M43 lens. What lens did you use? Did you shoot wide open? Did the Lensregain add any chromatic aberration that you had to correct in post?
Smallrig has a new T5 SSD holder that fits inside a wooden handle for their P4K cages. It should solve the problem of a tight fit of the old SSD holder against the Lensregain's transmitter.

Re: Metabones + Pocket 4K

PostPosted: Mon Feb 18, 2019 9:00 pm
by michaeldhead
dondidnod wrote:Michael, Nice professional looking short. Remarkable bokeh for M43 lens. What lens did you use? Did you shoot wide open? Did the Lensregain add any chromatic aberration that you had to correct in post?
Smallrig has a new T5 SSD holder that fits inside a wooden handle for their P4K cages. It should solve the problem of a tight fit of the old SSD holder against the Lensregain's transmitter.


Donald, thank you! I was using a Rokinon DS Cine lens (35mm) and shot mostly at f/2.8, ISO 2000 (if I recall correctly on the ISO). 4k DCI Prores 422 (man, I'm looking forward to Blackmagic raw! I hope it's this month).

I was very pleased with the look even in the low light. I did not have to remove any chromatic aberration. I wish I'd taken a picture of the frankenrig I was using: a Glidecam HD, with a rail system and remote follow focus, the P4k in a Smallrig full cage with a Sandisk Extreme SSD strapped on top, with a battery plate at the bottom of the Glidecam. But it worked well (although not fantastically balanced, but I'm working on that) and I'm sure I'll use it again soon! It was a lot of fun.

I first considered the Lensregain a while back, but when the price dropped to $199, I couldn't help but give it a chance (compared to the $600+ Metabones).

Metabones + Pocket 4K

PostPosted: Tue Feb 19, 2019 2:32 am
by rick.lang
Rado Stefanov wrote:I got the Metabones canon adapter only for my Sigma 18-35mm and 50-100mm and the infinity focus is off by a lot. Without the glass is there a way to fix that?


No glass in the Smart Adapter so presumably there’s no adjustment on the SpeedBooster that will vary the FFD. Correct, Rado?

When you focus at infinity, is your focus before the infinity witness mark (like at a 60’ mark) or beyond the infinity witness mark (if the lens barrel allows you to go beyond infinity)?


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Re: Metabones + Pocket 4K

PostPosted: Tue Feb 19, 2019 5:41 am
by Denny Smith
Sounds like a bad adapter or the two lenses have a bad FFD setting.
Cheers

Re: Metabones + Pocket 4K

PostPosted: Tue Feb 19, 2019 6:14 pm
by Rado Stefanov
rick.lang wrote:
Rado Stefanov wrote:I got the Metabones canon adapter only for my Sigma 18-35mm and 50-100mm and the infinity focus is off by a lot. Without the glass is there a way to fix that?


No glass in the Smart Adapter so presumably there’s no adjustment on the SpeedBooster that will vary the FFD. Correct, Rado?

When you focus at infinity, is your focus before the infinity witness mark (like at a 60’ mark) or beyond the infinity witness mark (if the lens barrel allows you to go beyond infinitely)?


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Before.
Sigma 18-35mm/50-100mm and Canon 24-105mm markI

Re: Metabones + Pocket 4K

PostPosted: Tue Feb 19, 2019 7:26 pm
by Denny Smith
So the adapter FFD is short of the required 24.75mm needed to make the MFT mount to lens the required 44mm EF FFD. Have yiu tested the lenses on another EF mount camera?
Cheers

Re: Metabones + Pocket 4K

PostPosted: Thu Apr 02, 2020 1:24 pm
by earthling
Thank you Rick for this great info which goes way beyond just the pocket 4K. This concerns all users of Speed Boosters or of any of the cameras you list here, which are numerous. I had come to the conclusion that my BMPCC4K with a 0.71 Speed Booster matched approximately using S35 lenses. Your numbers confirm that and it makes me very happy as that is the reference I'm used to.
Cheers,
Damien

rick.lang wrote:
Sean van Berlo wrote:Both work, however the 0.64x only works with full-frame lenses (but gives you a larger magnification and more light) whereas the 0.71x also works with aps-lenses...


Sean, there may be some confusion on the suitability of the focal reducers using the wider dimension of sensor on the BMPCC4K. People’s impressions of the focal reducers’s suitable taking lens may have been formed by their use on the BMCC or original BMPCC. But those sensors are significantly smaller. Here’s the current math normalized to the horizontal ‘crop factor’ which does come in handy for such quick comparisons. Comparing the sensor diagonal would be a little more accurate, but I don’t think the results differ.

mFT lenses suit cameras with a sensor crop factor around 2x crop
APS-C EF-S lenses are designed for sensors with a crop factor of about 1.6x
APS-C DX lenses are designed for sensors with a crop factor of about 1.53x
Super 35 lenses are designed for sensors with a crop factor of 1.44x
APS-H lenses suit cameras with a sensor crop factor around 1.2-1.3x (I forget).

URSA Mini 4.6K sensor has a crop of about 1.42x
Super 35 24.9mm sensor has a crop about 1.45x
BMPCC4K 18.96mm sensor has a crop of 1.9x
mFT traditional camera’s 17.3mm crop is 2.08x
BMCC has a crop of 2.28x
BMPCC has a crop of 2.88x

Ultra 0.71x reducer shooting open gate:
1.9x0.71x = 1.35x full frame (or APS-H) required
2.08x0.71x = 1.48x Super 35 or greater work
2.28x0.71x = 1.62x APS-C or greater
2.88x0.71x = 2.04x APS-C or greater

XL 0.64x reducer shooting open gate:
1.9x0.64x = 1.22x full frame required
2.08x0.64x = 1.33x full frame (or APS-H) required
2.28x0.64x = 1.46x Super 35 or greater
2.88x0.64x = 1.84x so APS-C or greater

0.5x reducer (modify Pentax version):
1.9x0.5x = 0.95x VistaVision required;
some full frame may work such as Zeiss CP2/CP3 and SLR Magic APO.

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Re: Metabones + Pocket 4K

PostPosted: Thu Apr 02, 2020 8:14 pm
by rick.lang
Damien, I do feel the Ultra gives the best results, even though I use lenses that ‘work’ with the XL, I prefer to be more conservative.