user23732: I am currently figuring out which lens I should get. I found the Sigma 18-35mm, f/1.8 DC HSM ART which looks quite interesting as I want to have a nice bokeh and shallow DOF.
But it is for APS-C only.
I will use the Metabones Speedbooster 0.71x on my BMPCC4k, so the crop factor is 1.349, so slightly bigger than 1.5 of APS-C. Is the image circle of the Sigma big enough to support 1.349 crop without much vignette?

I found this image on https://www.the-digital-picture.com/Comparisons/Sigma-18-35mm-f-1.8-DC-HSM-Lens.aspx and if I have done it right, the red circle is my "MFT" and the golden one is APS-C. Could anyone check if it's done right?
Also, does anybody know if it has a direct focus or a servo focus?
Thanks!

user23797: Your calculations are right.
But if you take a look here: https://www.fredmiranda.com/forum/topic/1279757/0
The vignette is much stronger. With the images provided by Aloicious I get a vignette.

23732: <p>I am currently figuring out which lens I should get. I found the Sigma 18-35mm, f/1.8 DC HSM ART which looks quite interesting as I want to have a nice bokeh and shallow DOF.
But it is for APS-C only.</p>

<p>I will use the Metabones Speedbooster 0.71x on my BMPCC4k, so the crop factor is 1.349, so slightly bigger than 1.5 of APS-C. Is the image circle of the Sigma big enough to support 1.349 crop without much vignette?</p>

<p><a href="https://i.stack.imgur.com/nj0sj.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/nj0sj.png" alt="Image Circle"></a></p>

<p>I found this image on <a href="https://www.the-digital-picture.com/Comparisons/Sigma-18-35mm-f-1.8-DC-HSM-Lens.aspx" rel="nofollow noreferrer">https://www.the-digital-picture.com/Comparisons/Sigma-18-35mm-f-1.8-DC-HSM-Lens.aspx</a> and if I have done it right, the red circle is my "MFT" and the golden one is APS-C. Could anyone check if it's done right?</p>

<p>Also, does anybody know if it has a direct focus or a servo focus?</p>

<p>Thanks!</p>
 23797: <p>Your calculations are right.</p>

<p>But if you take a look here: <a href="https://www.fredmiranda.com/forum/topic/1279757/0" rel="nofollow noreferrer">https://www.fredmiranda.com/forum/topic/1279757/0</a>
The vignette is much stronger. With the images provided by Aloicious I get a vignette.</p>
