Angenieux 25-250mm HR - Spherical Aberrations

[Justin Machacek]

Yesterday we mounted an Ang 25-250mm HR, a Cooke Mk 3 25-250mm, Zeiss standard prime, and a Red Zoom lenses (not the pro version).

What I immediately saw on the Ang was spherical aberrations on the left and right side of the frame. What one might call corner pinning. I didn't see it after zooming to about 55mm or more.

The lense was great, it only weighed about 10.5lbs with the motor and the gears were tight with no give. The glass was a bit warmer than the Reds and a lot warmer than the Zeiss primes. Also, it gets you about 100mm more range than a set of 2 Red Zooms.

I'm looking to purchase lenses for our new Red package. Now its down to Red Zooms or Angenieux HR and I'm wondering if anyone else has experienced the spherical aberrations that come into anything wider than about 55mm?

Thanks for any input... Justin Machacek

BTW - All of the zooms had a lot more breathing than I thought I'd see.

 

[Charles Angus]

I think you mean geometric distortions - where straight lines look curved? Spherical aberration is when the lens uses spherical elements which focus light coming from the edge and the centre of the lens at different distances, causing a "soft focus" effect.

Wide angles (especially 10x zooms at the wide end) are notorious for geometric distortions. You can live with it, correct it in post, or use a better corrected lens (probably a prime or wide zoom).

 

[Justin Machacek]

thanks Charles. Yes, thank you for clarifying... it is geometric distortions that are the culprits here.

Can you speak specifically to the angenieux 25-250mm HR? the geometric distortions are bending vertical objects from approx. 55mm zoom and below. I would appreciate anyone's input as to if this is typical of this particular lense.

 

[Harry Clark]

Hi Justin.
I own one of these lenses and they are great in terms of size and weight as compared to the Optimo 24-290. But there definitely are issues that come with the compromises made in order to achieve the compact form factor. It's relatively slow (T.3.5) and close focus is pretty far away (5' 6") It also has quite a bit of zoom effect when pulling focus, across the entire zoom range.
I have seen distortion (pin cushioning) and focus falloff at the edges of the frame with mine when on the wide end of the zoom range. However, light falloff is pretty negligible.
The focus falloff and pincushioning showed up a little worse last week, shooting on an F-35, than it had in the past, shooting on my Reds. Not sure why.
I assume that you'd need to be fully aware of this when the new cameras come out as the sensor will be bigger and more of the "poor" image at the corners will be part of the frame.
I think that the lens is certainly sharp in the center, and it's flattering to people's faces, but there are lots of things to watch out for with this lens.
Cheers,
Harry

 

[Justin Machacek]

thanks so much Harry... I have decided to give the Cooke 25-250 Mark 2 a really hard look (I read it's the same optics as the Mk 3, but not confirmed). We mounted a Mark 3 that same day and the pin cushioning was much more moderate while resolution was still sharp. I didn't like the weight of the mark 3 coming in at 16lbs without a motor. The Ang came in at 10.5 with a motor. I like the additional range of 150-250 so that's one reason I'm leaning away from the new red zooms (plus they are two lenses vs. one). also, the gears seemed a little loose to me on the reds. so now I'm left with the Ang HR and the Cooke Mark 2... BTW reseller said Mk 2 comes in at about 8.5lbs.

So here I am with the decision of spending an extra 10k to get the Ang or going with the cooke Mk II and have budget left for hand-held rigs, microforce, and a few other niceties.

Have you compared the Cooke Mk II and your Ang HR?

thanks a million for some really great information.

Best
Justin