Starting from scratch... Lens brand and mounts?

[Steve Kalle]

Originally Posted by Allan Tabilas

Hey Steve did you get a chance to use the 16-50mm f/2.8 lens? If so did you use it with the LA-EA2 alpha a-mount to e-mount adapter? thanks

This lens and adapter have not been released for sale yet (sometime in October) but a few websites have received the lens for testing. Sony Lens: Zooms - Sony 16-50mm f/2.8 DT SSM SAL1650 - SLRgear.com!

One thing to realize is this lens only covers the S35/APS-C sensor whereas other high-end Alpha lenses are FF (Sony G 28-75 2,8; Zeiss 16-35; Zeiss 24-70; Zeiss 85 1.4 & 135 1.8; Sony G 70-200 2.8). Personally, I prefer to use the FF lenses because you use their sweet spot.

However, for cinematography, the only SLR lenses I would rely on are the cine-converted Nikon mount Zeiss and only the newer ZF2 because they lack breathing and are sharper whereas the original ZF lenses suffer from breathing.

[Steve Kalle]

Originally Posted by Dominik Krol

I dont really get the whole par forcal/non parfocal issue..

I thought that a backfocus adjustment was designed to take care of that?

Please google the terms and do some research. Unless you have a killer AC who can manage zooming AND pulling focus at the same time, then you want a parfocal lens which doesn't change focus while zooming. On a related subject, you also should want lenses which do not "Breathe" - which means changing focal length while focusing. Almost all SLR lenses breathe, even primes, because it is a non-issue for still photography. The only SLR lenses that do not breathe that I know of are the ZF2 Zeiss.

[Dominik Krol]

Please dont answer if you just want to mock me and say "google it"

Googling non parfocal, tells you that: it doesn't keep it's focus throughout the zoom.

I knew that information already.
Furthermore every lens is by that definition NON parfocal until the backfocus is adjusted.

So let me ask again in a more comprehensive way: Why wont "non parfocal" lenses become parfocal after a backfocus adjustment?

[Steve Kalle]

Hi Dominick,

Sorry, but I didn't mean to mock you.

Can you explain what you mean about backfocus and parfocal....or should I just google it (taking some of my own medicine :p

[Dominik Krol]

:)

What I asked was apparently more complex than I myself had thought.

I will try to break down my thought process, and then you can tell me where I go wrong.

So..

Most if not all video cameras with interchangeable lens mounts have a backfocus adjustment on the lens mount correct? (exept the Sony Ex3 which has a electronic backfocus on the sensor itself, and the Canon XL series since they only accept one type of lens)

All Cine lenses are supposed to be adjusted for backfocus when attached to the camera correct?

The purpose of backfocus adjustment is to make the zoom go through without loosing focus (parfocal) correct?

If all of above is correct, then why cant ALL lenses in the world be backfocus adjusted and become parfocal?

[Duncan Craig]

You are really not just accepting the simple truths.

It's not a simple case of backfocus.
I believe the optical elements within a parfocal lens need to move differently from one another during zooming to hold focus.

Varifocal lenses are mostly going to be much simpler and cheaper, and design for stills camera where refocussing isn't a problem.

A lens is really complicated, it's not just two bits of glass.

[Steve Kalle]

This is what I think: the back focus adjustment is a stationary adjustment meaning that it doesn't move after it is set. A non-parfocal lens has glass elements that move during zooming which affect the focus plane. So, the back focus adjustment cannot dynamically compensate during the lens zooming.

[Mark Kenfield]

For a cheap and easy way to get started, I'd be looking at Nikon AI-S manual lenses with an adapter (or the Zeiss ZF2s if your budget can stretch to that). Get 77mm step-up rings for every lens and then purchase a high quality 77mm vari-ND.

Having de-clicked aperture rings are nice, but there aren't really many situations where changing the aperture (and the resulting changes to DoF) is favourable over being able to simply raise or drop the exposure with ND. With small sensor cameras, where everything was in focus anyway, it didn't make a big difference, but with a S35mm sensor, ND is definitely the way to go.

With the focus peaking on these cameras (I haven't seen the FS100 yet, but I've played with the F3 and assume they're similar) manual focussing is a LOT easier than it would otherwise be, and having the hard focus stops of a manual Nikkor/Zeiss lens makes it a lot easier to keep consistency in focus pulls over the modern SLR zoom lenses.

[Brian Drysdale]

Aperture adjustments do get made during the filming of some shots, it's here where the de clicked rings would have an advantage.

Cine lenses are collimated by a lens technician so that they're correctly set up. The flange depth of the cine camera can by checked by a camera technician at the rental house or repair shop, it's not something that's done on the set by the crew since they use shims for the adjustment. Some S35 digital cameras do allow for flange depth adjustment, but very often people get these cameras set up in advance and don't touch it on the set unless there appears to be a problem.

[Monty Wentzel]

Originally Posted by Monty Wentzel

I don't own the camera yet but I am purchasing a Rokinon 85mm prime. This is a manual lens, focus and iris are on the lens. I selected Canon Ef mounts and will use a dumb converter. I shoot with a 7d now and want to see how the Rokinon lens does.

Later I may just order a set of Rokinon lenses with E mounts to use with the FS100 or may just order them all with Canon mounts and continue to use the converter if there are no problems with using it.

Don't really know yet.

I received the Rokinon 85mm manual lens and placed it on my Canon 7d. It's a manual lens, but it works fine, the image is very very good. This is a fast lens 1.4. I used a variable ND fader ring on the front of the lens and shot some video at 1.4 and used the fader to get the right exposure. It was the middle of the day and bright sunlite, but with this setup I was still able to get a very shallow dof.

My goal is to get the sony fs100 and use this lens with the ProOptics adapter, which is an sony E to Canon EF mount.

I still don't know if I should just order the Rokinon lens with E mounts and just do away with the adapter.

As so many have said the Rokinon lenses are heavy and the 85mm is rather heavy so placing it on an adapter I'm told will make the camera front heavy.

I would love to see a side by side with a Canon "L" or some Zeiss lenses next to a Rokinon lens.

Let me just say back in the day we used to design auditorium sound systems and it was real easy to over design the system to the point that the sound quality was lost on the average persons ability to hear it. I wonder if lenses aren't crossing this line as well. Just as with sound systems, the specs and electronic measuring equipment documented the sound was great, but only dogs could hear the great frequency we were delivering. Lens specs may read great, but can we really see it?

[Shawn Sutherland]

Originally Posted by Shawn Sutherland

Does anybody own a Sony NEX-FS100 along with the Tokina 11-16 2.8 lens?

Hope so.

If you do, I'll assume that you're using the Sony Alpha LA-EA1 Camera Mount Adapter. (correct me if I'm wrong)

I don't know if you've already tried this, or have time to, but I'd love to see some footage from the FS-100 / Tokina 11-16 2.8 lens combination.

Stills, videos, I don't care. I'll take them all.

I just want to see how that lens works on this camera.

If you have any footage showing 11 through 16, that would be amazing.

I can't thank you enough.

Still waiting for that elusive FS-100 / Tokina 11-16 2.8 lens footage.

Anybody?

[John Godwin]

I have the Tokina 11-16. I'm out of the country so posting with a lens I don't have with me is not possible. But I will say the lens looks great at 2.8 with the FS-100.

Best,
John

[Monty Wentzel]

Originally Posted by Ryan Creason

I didn't think Rokinon made lenses in E-Mount - only A-Mount for Sony. Correct me if I'm wrong though.

At Rokinon.com | Rokinon Optics it seems they do have an "E" mount lens. I just chose to get Canon Ef mounts so I could use the lens with my Canon 7d and if the lens turned out to be less than expected I thought it would be easier to sell with a canon mount.

So far I love the lens and I love manual iris and focus too. The one item I do miss and I miss it a lot is stablization.

I can't hold an 85mm lens, it had to go on a tripod.

I also purchased a ProOptic adapter to fit the "E" mount on the future FS100. The adapter fit very well to the Canon mount lens but it is hard to release the little latch.

Monty

[Ryan Creason]

All I see on their website is their A-Mount here: Rokinon.com | Rokinon 35mm F/1.4 Wide Angle Lens for Sony - RK35M-S. Where is the E-Mount at?