October 1, 2015 at 7:46AM, Edited October 1, 7:49AM


BMPCC + Speedbooster question

Hello everyone,

Looking for some advice here. I've recently purchased a BMPCC and an EF Speedbooster and their on their way to me now. I bought the speedbooster mainly because I'm coming from a Canon background and have a couple thousand dollars worth of Canon lenses.

Obviously, I would like to continue to invest in more glass, considering my current collection still isn't enough for my needs. I shoot short films, as well as event coverage, short documentary style films, music videos, and other various freelance.

My question is, for future glass, should I ignore the Metabones Speedbooster and buy some Micro 4/3 lenses due to the range of lenses, or is it a better idea to permanently use the speedbooster and buy more Canon mount glass (which will come in handy for interchangeability. I plan on keeping my Canon DSLR for other projects and a secondary camera). Is the speedbooster's benefits worth having all the time? Maybe shallow depth of field? I'm wondering if this question has an obvious answer. I don't have much hands on experience with the BMPCC or the Speedbooster.

Looking for some feedback from people who were in familiar situations. I don't have a huge budget, so I have to purchase each lenses wisely. I'm particularly interested in grabbing some of the Samyang lenses, which are made with both mounts.


To first approximation, a doubling of the size of an image diagonal increases the image area by a factor of two, which requires increasing the focal length by a factor of two to achieve the same field of view. To maintain the same aperture values (i.e., moving from a 25mm T2 to a 50mm T2) with a doubling of focal length requires doubling the volume of the glass, which is an 8-fold increase in weight. Again, to first approximation.

A speed booster allows you to add some extra weight and complexity to your m43 camera so that you can use lenses that are designed with glass that is 8x overkill for your purposes. Since you already have the glass, it is free. And since you probably already love some of that glass, you won't mind all its extra weight as you work with such a tiny camera.

But in all reality, an Olympus 12-40 f2.8 pro lens is just an amazing performer, and perfectly balanced with your m43 camera, compared with an EF 24-70 f2.8 plus a speed booster. In the case of the latter, you will have all kinds of fun trying to get a tripod base plate to connect to the camera without also interfering with the barrel of the EF lens. EF cameras and lenses are designed so that when mated together they are flat enough along their horizontal base so that this is not a problem. Or else the lens has a collar and a foot for the tripod. Ditto m43 cameras and lenses. When you put larger lenses on smaller cameras, you will likely need to look at getting a riser for the camera or compromising how the lens balances on your camera.

If you think that putting a EF 24-70 f2.8L lens on a speed-booster to achieve roughly a 14-35 f2.0 m43 equivalent...look at the Olympus 14-35 f2.0 lens. It's nice and expensive, and it is thick enough in the barrel that you need a riser, but its optical performance is mind-blowing. Ditto the 35-100 f2.0...I have both.

October 1, 2015 at 9:16AM


Ugh...small math error in the first sentence of the above. Obviously doubling the image diagonal increases the image area by a factor of four.

October 1, 2015 at 2:42PM


I have the same set up and so far have avoided m4/3 glass. Honestly not for any specific reason other than a very simple one: if I have the speedbooster (which is expensive!), I might as well use it! Having that extra stop is always nice. What I did is also bought a regular EF to m/43 adapter. That way I can get some different lengths and looks out of the same glass.
Nothing wrong with m 4/3 glass though. I've used the olympus 45mm 1.8 and the SLR Magic 12mm 1.6, both are really great. Guess it depends on the look you're going for, and possibly how small you want to keep your pocket set up (Speedbooster + Canon glass will always make it a tad bigger).
Sorry this doesn't help, haha. Guess my point is, it all really comes to personal opinion. Like you said, keeping EF mounted glass might be a little more future proof (depending on the types of camera systems you're working with and will work with in the future).

October 1, 2015 at 3:29PM

Ben Meredith

No no, this helps! That's all I was looking for. Basically just wondering if anyone feels pidgeonholed by not buying any m4/3 glass. I don't mind adding the extra size it contributes to the set up, and I'm thinking I'll want the Canon glass for my DSLR sometimes as well.

I think my plan would be, considering the speedbooster doesn't decrease image quality, is keep buying Canon glass and maybe lookout for some cool and cheap vintage glass on ebay or something.

Thomas Shomo

October 1, 2015 at 6:24PM

Yeah definitely a good way to go. I have a vintage c-mount which is really cool, but aside from that I use EF mount glass. Only other m43 glass I really would want to invest in is maybe a Voightlander or SLR Magic 12mm, just because they give such a cool look.

October 2, 2015 at 9:38AM

Ben Meredith

I've thought long and hard about the same question you ask. I decided in the end I would buy glass specifically for the BMPCC. Trying to get lenses that would go well with both the BMPCC and your Canon camera is, in my opinion, making too much of a compromise one way or the other. The speedbooster is almost the price of a lens, first of all. Second, any time you use the speedbooster, it's going to suck the battery life out of the BMPCC even more than the already atrociously short battery life. Finally, if you want a normal to wide angle look on your BMPCC, it will most likely leave you with a very wide angle look on your Canon (something you might not use a heck of a whole lot in your video productions).

Now, if you don't care about battery life because you have an external power source, then my points about the speedbooster are moot. In that case, you're not like me in that you don't mind increasing the small form factor of the BMPCC.

If you don't mind shooting VERY wide on your Canon so that you can have a normal to wide on your BMPCC, or if you don't mind not being able to shoot wide on your BMPCC so that you can use your Canon at less wide to normal angles, then my points about compromising one or the other are also moot. I guess in this case it would depend on what camera you want to shoot with more.

Since I prefer shooting with my BMPCC, then I favor buying very wide micro four thirds lenses for it. If I preferred to shoot with my Canon (5DMIII), then I would get a speedbooster and buy lenses primarily for the Canon and use the speedbooster to allow me to use them with the BMPCC.

In the end, it's up to you and how you do most of your shooting. But for me, since I love my BMPCC, I'll buy lenses specifically for it (wide micro four thirds glass) so that I can keep the form factor small (no large lenses and not so much need for external battery supply) and have wide angles of view.

Remember, the crop factor (!) is 2.88 from full frame to BMPCC. A 15 mm lens on the Canon will give you an equivalent field of view of 43 mm on the BMPCC (without a speedbooster). Using a 15mm on your Canon may be a little too wide for most purposes if you're filming with it.

Anyway, my opinions aside, happy shooting!

October 5, 2015 at 1:27PM

You voted '-1'.
Harlan Rumjahn
Low-level government official

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