Is Tamron’s 17-50mm f/2.8 The Perfect Blackmagic Lens?

Ever since the original Canon 5D MkII opened up the world of accessible large-sensor video, it’s been hard to stomach the reduction in field of view that a cropped sensor demands. I absolutely love the image quality that my Blackmagic Production Camera captures, but the 1.7x crop factor made it a challenge to keep working with the same lenses that I used with my 5D2.

For example, my go-to lens for wide-angle handheld work with the 5D2 has always been the Canon 20mm f/2.8, and my favorite general-purpose lens is the Canon 24-70mm f/2.8. But neither of those lovely pieces of glass work the same way on the BMPC, because of the crop factor.

After investing in a couple of new lenses (plus digging an old 8mm Peleng out of my closet), I set out to do a side-by-side comparison to determine what lenses I can count on, and which I should leave in the bag.

First up was the Peleng 8mm. I bought this Soviet-era marvel years ago to use with a Krasnogorsk 16mm film camera. I had used it for a couple of fisheye shots on my Canon 5D, but I’ve really never had much use for it.

Here’s what it looked like. For each lens, I’m showing a scaled-to-fit image and a 100% crop from the ProRes HQ 4K video file.

8mm 01

8mm 02

While the ultra-wide angle is impressive, and the vignetting could be dealt with, the lack of clarity in the image would be hard to justify for any serious production.

Next in line is the Samyang 14mm f/2.8. It’s pretty darn wide, but the fact that the front element is hemispherical, and therefore doesn’t allow for an ND filter, means that this lens can really only be used indoors or under overcast conditions (unless you have a really nice matte box rig with 4×4 ND filters).

16mm 01

16mm 02

It looks pretty sharp, although the clarity of the marsh grass is a little underwhelming for a modern prime lens. It’s certainly usable, and the fact that it will work on a full-frame camera makes it a reasonably decent purchase (although, if I hadn’t already thrown out the packaging, I would probably return it).

My most recent purchase is the Tamron 17-50mm f/2.8. This is an APS-C lens, so it won’t really work on the 5D. But, it gives me a range that’s similar to the 24-70mm f/2.8 that I use so much on my 5D2 (on the BMPC, this lens is equivalent to a 29-85mm on the 5D2).

Tamron 17 01

Tamron 17 02

I was very pleasantly surprised with the clarity of this lens at 17mm. Look at the detail in that marsh grass! Really nice, and – it seems to me – sharper than the Samyang prime.

My well-used Canon 20mm f/2.8 is next in the lineup.

Canon 20 01

Canon 20 02

This is a Canon prime, so I knew it was going to be sharp, but I was still pleased to see how good it looked at 100% crop. Still a strong contender!

The Tamron 17-50 is a zoom lens, so I took it to the other extreme – 50mm – and took a look.

Tamron 50 01

Tamron 50 02

Still pretty darn sharp! Here’s my Canon 50mm f/1.4 for comparison.

Canon 50 01

Canon 50 02

My conclusion is that the Tamron 17-50mm f/2.8 is a fantastic lens for this camera. It has a flat front element, so it will accept filters, and it has a field of view that will accommodate most commercial/cinematic scenarios. It seems to be as sharp as a Canon prime, and – while it’s not cheap – it costs less than half its Canon equivalent.

  5 comments for “Is Tamron’s 17-50mm f/2.8 The Perfect Blackmagic Lens?

  1. September 2, 2014 at 8:02 pm

    Great post, this lens looks great and at a great price. Thanks for sharing!

  2. matteusclement
    September 6, 2014 at 9:01 pm

    There seems to be two versions. One with and with out VC. Which one do you have? Will the BM work with the VC?

    • Alexander
      September 6, 2014 at 9:15 pm

      I don’t know what VC stands for, sorry! The links in the post go to the lens that I bought, if that clarifies it at all.

      • matteusclement
        September 9, 2014 at 10:50 pm

        Vibration control AKA image stabilization.

  3. February 13, 2016 at 11:03 am

    Wow!!Wonderful Pictures!You are Christian? because I’m caiistrhnI go to a Christian church here in Argentina, is BaptistIt’s amazing meet people caiistrhn there.Well goodbye, blessings!Chau!

Leave a Reply

Your email address will not be published. Required fields are marked *