BMPCC4K Lens suggestions

Hello BM Forum,

I have been using the BMPCC4K since I purchased it in 2019. I produce (write, shoot, edit) corporate video for a gas turbine and compressor manufacturing company, and I travel to industrial customer sites like gas compressor stations, universities, hospitals, and power houses.

I have been using the Canon EF lens, 24-105 mm 1:4 L ISII USM and Tokina Superwide Zoom Lens 11-20mm with the Metabones EF – MFT Mount T Speedbooster XL 0.64x
I also have an Ursa Mini with EF mount – and use the same lenses on that.

I am looking to get a new lens or lenses. I’m thinking of maybe going to a MFT lens for the BMPCC. What are some advantages of a MFT len over the EF lenses?

I need a lens I can use in run and gun situations, where I am documenting engine builds, or other manufacturing scenarios with mechanical engineers and technicians (not actors or other broadcast talent). Sometimes I’m in super tight spaces, so the Tokina 11-20 works well for that. Sometimes I'm not allowed too close to a running unit for safety reasons. I’ve noticed that dust has been a problem. I’ve had my co-worker clean the sensor on the BMPCC but I’m still seeing dust and schmutz. I thought maybe dust was getting in between the Speedbooster and the lens, so I’ve been diligently blowing the lenses and camera before each shoot. Unfortunately, I don’t have time to blow the dust off every time I change lenses, which can be several times throughout a shoot. I shoot outdoors and indoors, industrial settings.
I am usually by myself, doing pretty much everything as a one-man band. It is rare to get an assistant on my shoots. If I do, it’s a corporate communications person who knows nothing about media production.

I don’t use auto focus; I prefer to focus manually. I have a DJI RS2 gimbal for handheld shots, which needs to have hard focus stops. And the lens can’t be too large when I use the gimbal. As of now, I only use the Tokina wide angle on the camera when using the gimbal. The Canon 24-105mm is far too heavy and doesn’t have hard focus stops. I am also toying with the idea of getting a mirrorless camera just for the gimbal, so I don’t have to swap set ups in the middle of a shoot.

I'm shooting UHD ProRes 422.

Thank you in advance!!!

Rig:

2019 BMPCC4K
Metabones EF – MFT Mount T Speedbooster XL 0.64x
Canon EF lens, 24-105 mm 1:4 L ISII USM
Tokina Superwide Zoom Lens 11-20mm
Canon EF Lens, 50 mm 1:1.4
Tiffen variable 82 mm neutral density lens filter
Tiffen variable 77 mm neutral density lens filter
SmallRig full frame cage for BMPCC4k
SmallRig NATO hand grip for Samsung T5
Core SWX Powerbase EDGE Battery 14.8 volt Lithium Ion
Sachtler Tripod w/head - FSB6
Kinotechnik Optical Viewfinder - LCDVF BM5
DJI RS2 Gimbal Stabilizer and battery handle
Manfrotto unipod

I'd be concerned that you are using lenses wider than 20mm on a non-BMPCC 4K Metabones XL Speed Booster. When you shoot subjects at a distance, does the image look soft?

"Telecentric design to deliver light almost straight to the light-receiving section
…Pursuing telecentricity with state-of-the-art optical technology.

The detailed distortion-suppressing design provides high image quality without distortion at the centre and the edges."

Benefits of Micro Four Thirds.

https://www.four-thirds.org/en/merit/

Being a mount designed for a mirrorless camera, the M4/3 is telecentric.

Kyle Gordon wrote:

"I just saw a new clip on Vimeo that really illustrates the difference.

It's a lens comparison between four lenses:

Sigma 18-35mm @ 35mm
Zeiss CP.2 35mm
Schneider Xenon 35mm
Xeen 35mm

To recap:
Of the four, only the Schneider is telecentric, which means that the light falling on the edges of the sensor is coming down at an angle relatively perpendicular to the sensor plane, while the other lenses project onto the sensor in a way that the edges of the sensor see the light coming in at an angle, especially at apertures smaller than f/4, and increasing in effect to around f/8. On the 4.6k sensor, this angle causes a magenta cast around the edges. Since this test shows the four lenses side by side under the same conditions, it makes an excellent illustration. Look how amazing the Schneider looks on this sensor! ...in the end, the Schneider's image is greatly superior because of the color accuracy."

Magenta Vignette - Telecentric vs. Non Telecentric Lens

viewtopic.php?f=2&t=58642&hilit=Xenon+28

There are a lot of EF mount "dad cam" lenses out there (130 million) that were never designed for video work. Image quality sure can be good, but manual focus mostly worse than on FD lenses, and electrical focus tolerable only on few lenses. The same story with stepy f-stop, that can be controlled only electrically.

…I prefer the Arri PL mount to the EF because it is a more solid connection and is shimmable. To use a parfocal lens, you must use a shimmable mount, the tolerances are too tight for it to function otherwise. The PL mount can support heavy lenses due to it's positive lock, others get looser and wear out their spring with heavy lenses. PL mount lenses also retain their value.
A mirrorless mount has a short Flange Focal Distance that can adapt any Arri PL mount lens. An EF mount camera is more limited in adapting PL lenses due to restrictions on lens protrusion.

In choosing a mount, you have to ask, will the lenses for that mount be able to resolve well enough for modern higher resolution sensors?

A lot of people think that since it's an EF mount camera, they can use that old Canon 18-55mm kit lens that was designed back in 2003 for a 6.3 MP camera.

Although a 35mm film lens would need to resolve much more (20 MP?), an EF-S lens designed to be used on a 2003 Canon EOS-300D that has a resolution of 3072 x 2048 (6.3 mp), would only need to have an MTF of 3072/(23x2)= 66.8 lp/mm.

Some say that calling a lens a 4K, 6K or 8K lens is a marketing gimmick, there's a lot more to an image than resolution. There are several manufacturer's that market lenses that way however. A fairer method would be to publish independent MTF lp/mm scores as a measure of a lenses sharpness. This is seldom done though.

Tom Roper wrote:

"The problem is fundamental, inherent to the sensor size. To resolve the full pixels of the sensor, you take the horizontal pixels divided by twice the horizontal millimeters to get line-pairs/millimeter needed from the lens.

(BMPCC 4K - 4096/(18.96x2)=108 lp/mm

BMPCC 6K - 6144/(23.1x2)=133 lp/mm)

The lens for 12K footage on an Ursa needs to resolve 227 ln-pr/mm.

For 8K from the Ursa the lens needs to resolve 152 ln-pr/mm.

For 8K from the A1, the lens only needs to resolve 114 ln-pr/mm.

Because the sensor out-resolves the lens by more with smaller sensors than large ones, the same lens on the larger sensor will give the higher overall system resolution, which is what counts."

Robert Niessner wrote:

"...There are 4 different 16-35 L lenses from Canon. But regardless of the version, all of them are sharpest at f/5.6 In the center at f/5.6 the 16-35 L f/2.8 II and III can resolve around 45 line pairs per mm (MTF50)."

Re: 12k Ursa Not Sharp When Punched In

viewtopic.php?f=2&t=145731&p=780841&hilit=+take+the+horizontal+pixels+divided+by+twice+the+horizontal+#p780841

r/cinematography Is EF the best mount to invest in?

https://www.reddit.com/r/cinematography ... invest_in/

Jacquie, if you do run and gun work, you might have a look at the MFT lenses from Olympus.
I own the Olympus Pro 12-100mm f/4.0 and the 7-14mm f/2.8
All MFT lenses do have a lot of barrel distortion because the MFT system as a whole seems to rely on undistortion in software. But that is not a huge issue. I shoot in BRAW DCI 4K, and place the shots in Resolve as cropped input scale. Then I apply the lens distortion filter and scale the width to 0.96
That way I am not losing too much of resolution in the edges, but get nice straight lines, which I like for industrial jobs.

The Olympus Pro lenses are sealed and water/dust proof. Both lenses can be set from focus by wire to hard stops, but can also be focused directly by the RS2 focus wheel.
The OIS of the 12-100mm is outstanding and can be used even for pan and tilts without any hiccups. Naturally OIS can’t compensate on the roll axis, but this can be taken care of in post.
The 7-14mm has no OIS, but I use it only for establishing shots in rooms or for buildings on a tripod. It’s a great lens, too.

The trade off compared to your Speedbooster setup is of course over a stop of light loss. But I never found that really troubling. I also highly recommend to switch over from ProRes to BRAW shooting. It is much more convenient than you might think and more flexible in post especially with challenging situations like in industrial complexes.

Thank you so much for the responses! I appreciate the help.

@dondidnod

I'd be concerned that you are using lenses wider than 20mm on a non-BMPCC 4K Metabones XL Speed Booster. When you shoot subjects at a distance, does the image look soft?

I haven't noticed a huge difference between the Canon 24-105 and the 11-20 - except I get vignetting on the Tokina super-wide and the edges are soft. I fix distortion best I can in post.

These lenses were in-house already, given to me by a fellow employee to use. Since they are EF mounts, they can be easily shared for use on our Canon DSLRs and the Ursa Mini as well. At the time, it seemed like a good idea to purchase the Metabones Speedbooster to be able to share lenses.

I tend to use the BMPCC4K for travel. It is so nice to travel a bit lighter. I have to deal with international travel and the headaches that come with it. Carnets, lost luggage, broken equipment, customs agents and airlines that make it challenging to say the least.

I own the Olympus Pro 12-100mm f/4.0 and the 7-14mm f/2.8
All MFT lenses do have a lot of barrel distortion because the MFT system as a whole seems to rely on undistortion in software. But that is not a huge issue. I shoot in BRAW DCI 4K, and place the shots in Resolve as cropped input scale. Then I apply the lens distortion filter and scale the width to 0.96
That way I am not losing too much of resolution in the edges, but get nice straight lines, which I like for industrial jobs.

Thank you for this! I am looking at purchasing the Olympus Pro 12-100mm.

Do you have to compensate when shooting for the lens distortion with building shots? As in, get a wider shot than you would normally need? I went from film school shooting 16 mm film straight into local news broadcasting. As an ENG photog, I was so used to having ONE really good ENG lens on an ENG camcorder, and I had no idea how spoiled I was with expensive lenses that remain in focus, or having built in ND filters that are in the camera. Plus having a dedicated technical engineer in-house to do all the research and troubleshooting and upkeep of equipment. I have none of these things in my current position.

Do you have to compensate when shooting for the lens distortion with building shots? As in, get a wider shot than you would normally need?

A bit yes, but when you shoot in BRAW 4096x2160 for UHD 3840x2160 you have some wiggle room.
I made you an example:

DCI 4096x2160 source

DCI 4096x2160 as is_1.62.1-50%.jpg (795.48 KiB) Viewed 494 times

DCI 4k just cropped to UHD (left and right -128px each)

DCI 4k cropped to UHD_1.62.2-50%.jpg (838.45 KiB) Viewed 494 times

Note: Vignetting is from the Vari-ND on the front.

Slightly downscaled to 96% on the x axis:

DCI 4k cropped to UHD scaled x-axis by 0.96

DCI 4k cropped to UHD scale x 0_1.62.3-50%.jpg (835.99 KiB) Viewed 491 times

And now with some compensation for distortion & chromatic aberrations, downscaled to 94% on the x axis:

DCI 4k cropped to UHD scale x 0.94 dist & CA comp

DCI 4k cropped to UHD scale x 0_1.62.4-50%.jpg (750.56 KiB) Viewed 491 times

Have you thought about the Tokina T2.9 25-75mm? Mounts can be mFT, EF or PL.

https://www.bhphotovideo.com/c/product/1640890-REG

I recently purchased a Venus Optics Laowa 7.5mm f/2 MFT Lens for our 4K and have been very impressed with it. It's the first MFT lens I bought for it and now I'm surprised it's taken me this long to explore those lens options.