Widest lens for Pocket Blackmagic camera Bolex anamorphot?

[roccoforte]

I'm trying to figure out theoretically what the widest lens I can use with the new Blackmagic Pocket camera AND a Bolex 8/19/1.5 anamorphot.

Would the Voigtlander 17.5mm work? How about the 24? (EDIT: meant the 25)

Thanks for any input.

[Tito Ferradans]

Considering the 3x crop sensor, you'd probably be able to go with both lenses, but the 24 would be a safer bet.

[Julian]

If you know what is the maximum focal length you can use on your current camera, then you know what you can use on the Pocket. Just calculate everything back to fullframe.

 

For example: my Kowa 2X works on 35mm on my GH2 with 1,86x crop.

35mm x 1,86 = 65,1 (fullframe equivalent)

Divide 65,1 by 3 (cropfactor Pocket Camera) = 21,7mm

[roccoforte]

Thanks for the help. It's pretty easy when you know how!

[septemberdawn]

Good information.

 

I'm intending to use a similar configuration.

[itimjim]

I'm going to guess that a 17mm will 'just' about work on the BMPC. Based on the fact that I can get a 28mm working on my GH2 with my Bolex 16/32. Not all lenses are created equally though :)

[roccoforte]

Now I'm not so sure because 35mm on a my T2i vignettes too much:

 

 

T2i

 

50 x 1.6 = 80 (WORKS)

40 x 1.6 = 65 (WORKS)

35 x 1.6 = 56 (VIGNETTE)

 

 

GH2

28 x 1.9 = 53.2 (WORKS w 16/32)

 

BMPC

17.5 x 3 = 52.5 (NOT SO SURE) <----

25 x 3 = 75 (LOOKS GOOD)

 

But is the above calculation the ONLY way of figuring it out?

[Julian]

It also depends on the design of the lens. Some might vignette more than others, it should be a rough guideline.

 

I'm surprised it works on your GH2 with 53.2mm equivalent, but doesn't work on your T2i with 56mm equivalent.. what 35mm are you using on the T2i?

[roccoforte]

The 35mm on the T2i was the Zeiss 2.0 Distagon. Maybe I should try a different 35mm...?

 

RE: the GH2; I was referencing itimjim's post above mine (apologies for the confusion). Which is also a different anamorphot, so that may account for the difference too.

 

It's anyone's guess, I suppose. Just gonna have to drop $1200 to find out!

[brucker]

how far off is the sensor from nikon v1's cx?

 

and how does the bolex rear measure? 

 

a couple of anamorphics i have might be similar in size so i could try it out on the nikon v1 if you want.

[septemberdawn]

how far off is the sensor from nikon v1's cx?

and how does the bolex rear measure?

a couple of anamorphics i have might be similar in size so i could try it out on the nikon v1 if you want.

Bolex 8/19/1.5x rear element is 20mm

[JohnBarlow]

There are some nice cheap cine zooms out there, something like a 2/18-90mm would be perfect

[septemberdawn]

There are some nice cheap cine zooms out there, something like a 2/18-90mm would be perfect

 

Could you point me to some?

[brucker]

Bolex 8/19/1.5x rear element is 20mm

 

ok,.. the rear on my shigascope and izukarscope are smaller, 17mm and 19mm respectively.

 

from here i'll use the focal length of lenses for 35mm still photography to avoid any confusion, so multiply by x2.7 for the field of view:

 

on a nikon v1 cx sensor which has a crop factor of x 2.7, a 28mm takumar vignettes.

 

a 35mm takumar doesnt vignette.

 

i did play with a v1 zoom lens that went from 24-something in the shop and i put my shigascope infront, and it would be ok till about 30mm. after that the vignette starts to appear.

[JohnBarlow]

Could you point me to some?

http://www.ebay.com/sch/i.html?_odkw=vario&_sop=10&_osacat=625&_from=R40&LH_PrefLoc=2&_trksid=p2045573.m570.l1313.TR0.TRC0&_nkw=vario+switar&_sacat=625

[Tito Ferradans]

Could someone tell the difference (pros and cons) between the 16/32 and the 8/19 versions of the Bolex?

I know the second one is smaller, but that's all! :)

[JohnBarlow]

16/32 means it has rear aperture of 32mm and was intended for 16mm film

8/19 means it has rear aperture of 19mm and was intended for 8mm film

 

both are 1.5x and made by Moeller but some say the Bolex ones are higher quality (unproven)

 

there are 2x models also like 30/2x and 32/2x as well as the bigger cinema projection lenses

[Tito Ferradans]

Thanks JohnBarlow!

And what about image quality between them and vignetting on full frame? Exactly the same, or one has better results against the other?

[JohnBarlow]

Not suitable for FF

 

Like all Moellers IQ is top

[Tito Ferradans]

What's the front thread, on both 8/19/1.5x and 16/32/1.5x ?