Fly-by-wire lenses

[Mozim]

Hey, 

is it possible to upgrade lenses that focus electronically instead of mechanically in a way that they have a constant, linear focus? 

When I picked up a MFT camera, I actually liked the build quality of the native lenses that I bought along with it (Panasonic 25mm f/1.4 and Olympus 45mm f/1.8). The focus rings feel good and there's an alright stiffness to them... plus I like using native lenses. When I started shooting video with them, however, I found them to be pretty much unusable for pulling focus manually because they don't focus in a linear way. If you turn the focus ring quickly, it'll go from close to infinity almost instantly. If you turn the focus ring slowly, it'll take much, much longer to focus from close to infinity. This means that it's impossible to replicate focus pulls and I can't rely on these lenses at all when shooting video. 

I noticed that the new Sony lenses focus the same way, and apparently the new Samsung lenses do that, too. To me (and to many other shooters who focus manually) this means that all these really good native lenses are pretty much useless for shooting video. 

I don't know the technical details, but since these lenses focus electronically, it must be possible to have different focus modes, right? Is this something that could be fixed by a firmware update? What do you think? 

[Andrew Reid]

Some like the Olympus 12mm F2.0 have a mechanical mode, you pull back the focus ring to engage the gears.

A linear focus travel is something mirrorless manufacturers really need to start giving us, as a menu option.

And on future high end lenses they should also consider a switch which engages hard stops when in linear focus travel mode.

The current non-linear fly by wire system that's become so common is total nonsense really. Should never have been designed that way.

[Mozim]

Some like the Olympus 12mm F2.0 have a mechanical mode, you pull back the focus ring to engage the gears.

A linear focus travel is something mirrorless manufacturers really need to start giving us, as a menu option.

​It surely must be a lot easier and cheaper for the manufacturers to enable linear focusing as a menu option / firmware update instead of adding a mechanical mode? 

Glad to hear that you feel the same way. Maybe if enough people chime in, the manufacturers will realize that this is a serious issue for filmmakers. I would have no issues whatsoever investing heavily into the MFT lens system if I knew that I could use the native lenses for stills as well as for video. They're perfectly fine for stills but unusable for video because of the focus mode. 

[jase]

Some like the Olympus 12mm F2.0 have a mechanical mode, you pull back the focus ring to engage the gears.​

 Thats what i thought, too. But sadly event this is not true. If you focus in this mechanical mode, you still have no linear focus pulling. What happens when you pull focus from let's say 0.3m to 0.8m: while turning the wheel nothing happens. then, short before the mark, the lens immediately switches to the corresponding point. I can post a video later to explain what i mean if that is wanted.

To the OP: +1 - also for me this is very annoying.

[Don Kotlos]

 Thats what i thought, too. But sadly event this is not true. If you focus in this mechanical mode, you still have no linear focus pulling. What happens when you pull focus from let's say 0.3m to 0.8m: while turning the wheel nothing happens. then, short before the mark, the lens immediately switches to the corresponding point. I can post a video later to explain what i mean if that is wanted.

To the OP: +1 - also for me this is very annoying.

​Yes this is how the manual "mechanical" focus is implemented in some of the olympus and fuji lenses. Still fly by wire, but they have set markings on the focus ring. Nothing with gears.. 

So while this is still useful for street/still photography it is not as good for video since the focusing is far from smooth (unless you focus really slowly). Still better than purely fly by wire since no matter the focusing speed the location of the ring determines the focus. 

What they could do with a firmware update is during video mode the transition between focus points to be very smooth. It is very easy to do and I am sure if they think about it, they will do it. Any olympus engineers around? 

[JazzBox]

Some like the Olympus 12mm F2.0 have a mechanical mode, you pull back the focus ring to engage the gears.

A linear focus travel is something mirrorless manufacturers really need to start giving us, as a menu option.

And on future high end lenses they should also consider a switch which engages hard stops when in linear focus travel mode.

The current non-linear fly by wire system that's become so common is total nonsense really. Should never have been designed that way.

​I have that lens: it is really amazing (fast, sharp, great image quality, super straight etc...) but in the mechanical mode has an issue that I really don't like: if you pull the focus very slowly you see your image shifting focus in micro steps. It's very annoying

I returned to the shop and try 3 other identical lens and I had the same results. I hope they could resolve it in a future firmware update, because it's a quite expensive lens... and I'd like to use it in the mechanical mode.

Anyway, I use it in manual focus in the standard (endless) way, because in that way it has not micro steps.

Apart that it is one of my favorite lens and I use it a lot. Just don't use it with a follow focus or gears, because it's a waste of money. 

[andy lee]

on a different note - I recently 'gutted' a fly by wire lens and make it flly manual.

I picked up a broken Nikon 18-105mm f3.5 fly by wire lens off ebay that had been dropped.

So I took it to bits removed all the motors and took out the fly by wire apperture . ripped out all the circuit boards and ribbon cables

re assenbled it into a manual fully wide open lens , araldited a Canon adapter on the back as the plastic Nikon mount was broken.

It works very nicely as a manual lens now - just add NDs to drop the light into it - and it was £20 off ebay broken.

 

 

[Joe Gunawan Fotosiamo]

Yes, this is a highly annoying "feature" of many native mirrorless lenses. It's almost a worthwhile reason to get the Zeiss Loxia lense for the a7 series. I believe those allow for linear focusing, but I could be wrong..

[Rolf Dergham]

I've been doing some research on the topic. I also hate this "feature". They should concentrate on making better and more stable interfaces instead of such "features".

I am not sure, but it seems to me (after tesnting it) that Panasonic bodies have a more "linear" focus-by-wire ratio. I could not find any confirmation online, though.

Olympus and Sony, unfortunately, definitely use variable focus rates by default. Yet some Olympus lenses have a linear mode where you can have something which mimicks traditional manual focus, even with hard stops. They're the more expensive lenses though. Why should I have to pay premium and limit myself to these lenses just to avoid the crap that they created in the first place.

Focus by wire can be useful. For example, it would be great to have a button that you can press for "precision focus" adjustements, and keep a linear ratio otherwise. In other words it can be useful to change the focus ratio, but not automatically and all over the place like it is done now.

For now the only real solution is proper manual focus lenses. They're a pleasure to use in comparison.

[Geoff CB]

Yeah I wish mirrorless cameras would support offering a linear focus mode for their fly by wire lenses.  I don't see why they don't, it encourages filmmakers to purchase their native lenses instead of adapting 3rd party glass.

[leeys]

I've mentioned this before on DVX; it's like mouse acceleration. You can turn it off in your OS options. Why can't we do the same in mirrorless cameras? It's all software anyway. Olympus even includes an option to change the direction of the focusing ring, but not this. Even when doing stills the behaviour annoys me.