Follow focusing still lenses... (the real scoop)

[Evin Grant]

With the first Red one's delivering today I decided to use my pent up anticipation for something useful. I've been holding off more lens reviews till I can get ahold of a Red and test more brands and more mounts than just Nikon. But I did just take delivery of a shiny, almost new Chrosziel pro single sided follow focus, so I decided to take some Nikkors out for a test drive, albeit on an old Nikon F2 fitted to a DVX100 base plate but it still gave me the platform necessary to do some informative teting about the viability of using manual focus (and AFS) still lenses on the Red with a traditional mechanical follow focus. I created marking disks corresponding to the distances on the lenses and checked for accuracy with a tape. What I found was encouraging.

I'll start with the good news, longer lenses like the 85mm f1.4 and 135m f2 have almost a full 360º of rotation on the follow focus ring.

The AIS 50mm f1.2 is not as good but with 170º or so should be useable. Certainly at f4 and beyond. The AI version should do better, probably around 220º but it only has 7 apertures blades instead of the AIS's 9 which I prefer the look of.

Wider lenses vary, here an early pre AI 35mm f1.4 has almost 270º of rotation! But the newer AIS 20mm f2.8 only has about 130º. In practice I don't think this will be a problem for the 20mm which has more DOF and a smaller starting aperture.

As expected the worst of the lot are the AFS zooms 17-35mm f2.8 & 28-70mm f2.8. These both had about 100º of rotation, but since the Birger AFS mount will allow you to map this to the full 360º this isn't as much a concern. Still in a pinch a well dampened follow focus like this Chrosziel should be able to allow for accurate focusing at f5.6 and the like. Any ACs out there care to chime in?

 

[Brook Willard]

Awesome man... great read.

Nice head too...

 

[Matt Garrett]

what gear rings are you using?

 

[Paolo Tinari]

Chrosziel should be able to allow for accurate focusing at f5.6 and the like. Any ACs out there care to chime in?

5.6 is a dream for me

 

[Evin Grant]

what gear rings are you using?

I'm not sure, I bought them off Ebay, got a whole set of seven. The are made of Delrin plastic and are matched to each lens diamiter. My guess is they are Cinetch or some smaller company, maybe even custom. It's hard to say. They seem about the same OD as the Redrock gears though.

 

[Matt Garrett]

Yeah, they seem like a nice fit. I like how thick they are.

 

[Jaime Vallés]

Thanks for posting this. I'm really torn between getting the Birger mount with AFS zooms, or the plain ol' F-Mount with manual primes and a follow focus. Too many options...

 

[Sanjin Jukic]

Thanks Evin.

Great report.

 

[Dan McCain]

Dont forget nikons are geared backwards from other cine lenses. A.C.s who are use to pulling focus in the standard direction will need a follow focus with reversing gear. Also the distance between the feet markers is very very compressed the slightest movement may jump from 5 feet to 10 feet for example. I wouldn't trust the witness marks, typically eye focus only.

I have been pulling focus on nikons at 1.4 (with mini35) for several years, be prepared to sweat when trying to pull focus with nikons, some shots are nearly impossible!!

 

[Finner]

With nikons and other still lenses being backwards focus compared with cine lenses a very good experienced focus puller will suck using it. I would recomend a wireless unit that can be reversed.

As far as rotation distance many cine lenses have a 720degree throw or more on a FF wheel. It is really needed quite often when dealing with the 5-10 foot focus zones.

All this said I am very hopeful for nikons being a good choice but I see no other way to do it right then a reversable remote FF unit or a FF that can be reversed (good luck as right now willy tech is the only one I know of). Big opportunity for some company to build a reversable FF. Red Rock are you listening?

 

[jbeale]

I have never used a FF unit, but it seems pretty simple in principle? One extra gear will reverse the direction- gears and gear trains have been in use since the time of the greeks so this is not exactly new tech...

Does a FF need to have zero backlash to be usable? I think the usual approach to low/zero backlash is to use gears split in two with internal torsion spring, to assure the teeth mesh tightly against the next gear; those types do tend to be more expensive.

 

[chuck colburn]

Called anti backlash gears. Ok for some uses but they don't feel very smooth when turning them by hand. If you can live with the kinda crunchy feeling then it's a possibility. Better to have a precision designed gear train combined with zero lash belts.

 

[Hrvoje Simic]

With nikons and other still lenses being backwards focus compared with cine lenses a very good experienced focus puller will suck using it. I would recomend a wireless unit that can be reversed.

As far as rotation distance many cine lenses have a 720degree throw or more on a FF wheel. It is really needed quite often when dealing with the 5-10 foot focus zones.

All this said I am very hopeful for nikons being a good choice but I see no other way to do it right then a reversable remote FF unit or a FF that can be reversed (good luck as right now willy tech is the only one I know of). Big opportunity for some company to build a reversable FF. Red Rock are you listening?

I have mentioned in the offtopic thread the solution I've been working on for a while now. It will have reversible directions, wireless add-on module, and you will be able to choose your own preferred rotation on the FF wheel for your own focus zones in the current shot. The optimal hand movement for the specific focus range.
Also, you won't need to draw lens markings, because you will be able to input them on the display for each individual lens. When changing lens you'll just recall your saved markings. These will not be all the features.

 

[chuck colburn]

With nikons and other still lenses being backwards focus compared with cine lenses a very good experienced focus puller will suck using it. I would recomend a wireless unit that can be reversed.

As far as rotation distance many cine lenses have a 720degree throw or more on a FF wheel. It is really needed quite often when dealing with the 5-10 foot focus zones.

All this said I am very hopeful for nikons being a good choice but I see no other way to do it right then a reversable remote FF unit or a FF that can be reversed (good luck as right now willy tech is the only one I know of). Big opportunity for some company to build a reversable FF. Red Rock are you listening?

Finner,

One of the Arri manual FF is reversable by mounting it upside down.
Model LFF-1

 

[pablokorona]

Dont forget nikons are geared backwards from other cine lenses. A.C.s who are use to pulling focus in the standard direction will need a follow focus with reversing gear. Also the distance between the feet markers is very very compressed the slightest movement may jump from 5 feet to 10 feet for example. I wouldn't trust the witness marks, typically eye focus only.

I have been pulling focus on nikons at 1.4 (with mini35) for several years, be prepared to sweat when trying to pull focus with nikons, some shots are nearly impossible!!

I feel your pain - now i'm curious though, are these new P + S re-engineered Zeiss SLR lenses appropriate for focus pulling? Am i reading the focus marks correctly? http://www.pstechnik.de/en/optics-lensset.php

These also appeal to me http://www.rplens.com/products.htm

Anyone work with/know about these?

you're right, the distance for focusing is temperamental and i'm looking for a better solution while still being more affordable than buying Zeiss Standards...

 

[Jim Hoffman]

It would seem also that slightly different gearing would allow for more travel of the FF against the focus ring of the Nikkor lenses yes? Seems simple???

Question - on older Nikon lenes there is a little lever on the mount that slides into the camera body - this holds the lens iris open to the maximum aperature so one can see clearly in the view finder - when the shutter is released the aperature closes to its user defined setting and then reopens to the max setting again. How is the RED Nikon mount addressing this issue? Is it that you just stop the lens down to the desired setting and the EVF compensates with gain??? So I guess that switch would be bypassed?

 

[Kevin Halverson]

Question - on older Nikon lenes there is a little lever on the mount that slides into the camera body - this holds the lens iris open to the maximum aperature so one can see clearly in the view finder - when the shutter is released the aperature closes to its user defined setting and then reopens to the max setting again. How is the RED Nikon mount addressing this issue? Is it that you just stop the lens down to the desired setting and the EVF compensates with gain??? So I guess that switch would be bypassed?

Cine applications don't have different VF characteristics for open and stopped down lens settings, so no, they won't make any use of this. Just set the EVF or LCD brightness as required.

 

[Jim Hoffman]

Cine applications don't have different VF characteristics for open and stopped down lens settings, so no, they won't make any use of this. Just set the EVF or LCD brightness as required.

Thanks - my question, I guess, is more along the lines of - The mount takes this switch into consideration for old Nikkor lenses and this switch WON'T interfere with the f=stop....right? I am a Canon user so I am not 100% sure that the non AF lenses all have these switches... but they would have to be bypassed on RED>?.?.?

So if you're answering "right" ... cool... thanks... just want to be sure.

 

[pablokorona]

It would seem also that slightly different gearing would allow for more travel of the FF against the focus ring of the Nikkor lenses yes? Seems simple???

see, that's the tricky part. Look at the first image in this thread. Noticed the HUGE gaps between the close distance, and the relative space between 10 and 15 feet - i don't think a gear, unless maybe its ellipsoidal, won't help much.

My general question is if cine lenses have even placed focus marks that don't ramp up in distance like these SLR lenses do?

 

[Kevin Halverson]

Thanks - my question, I guess, is more along the lines of - The mount takes this switch into consideration for old Nikkor lenses and this switch WON'T interfere with the f=stop....right? I am a Canon user so I am not 100% sure that the non AF lenses all have these switches... but they would have to be bypassed on RED>?.?.?

So if you're answering "right" ... cool... thanks... just want to be sure.

I guess I am not fully understanding your question so let me try this a different way.

In a cine application, you need to have the lens stopped down 'all the time'. It's not like a still SLR application where the lens is wide open unless exposing the frame or if the depth of field preview is used. The still application is a non-continuous use, cine is a continuous use. The exception, where both are effectively the same is when you set the lens to its minimum numeric f or t-stop (wide open).