FS5 kit lens focus issue in manual

[Nigel Davey]

Today for the first time I used my new FS5 with the 18-105mm kit lens on a couple of real jobs. Now and again the lens was doing something strange whilst in manual focus.

As you do I'd zoom right in, including digital zoom, magnify with the FN5 button, focus up, switch off magnification and start to zoom out. A couple of times possibly around the end of the digital zoom it went horrendously out of focus. Remember I was in manual focus when this happened and nothing had touched the focus ring nor the push auto focus button, it was just zooming out.

Something else I noticed was a couple of times when zooming in, focussing up and then slowly zooming out, by the time I was at the wide end the image looked ever so slightly soft. So then I'd FN5/magnify from the wide shot and sure enough the focus was out/soft. So if I then adjusted it to look sharp (on the wide), take magnify off and the zoom in... it would be soft at the end of the zoom.

Is this a known issue or do I have a dodgy lens or a back focus issue?

I haven't looked through the rushes yet, but I'm pretty certain I captured both these issues once or twice.

[Doug Jensen]

The 18-105 can't be counted on to be parfocal. Sometimes it might be, but usually not. When you zoom it is likely you'll lose focus. The best way to use that lens, if you must use it all, is as a variable prime.

[Nate Haustein]

This is an issue that has popped up a few times now and it has to do with the zoom rocker on the camera grip. The 18-105mm lens is supposed to be electronically parfocal, but as of now with the FS5, it only works as expected when you use the little zoom rocker on the lens.

Do a test using the camera rocker, and then the on-len lens rocker and see for yourself. Using the lens rocker, it should work and stay in focus.

[Nigel Davey]

Ok thanks guys, your feedback is appreciated. At least I know what is going on and how to get round it.

[Docea Marius]

This lens is terrible in manual mode,I put this lens in manual mode,zoom in ..end all Image is defocus.

[Nigel Davey]

I had to use the kit lens at two conferences this weekend due to the run-n-gun nature of the activities. It was challenging. In fact I'll go as far to say you can't call the FS5 a run-n-gun camera with the SELP18105g.

Anyone who has used this combination knows the autofocus is slow. Too slow for anything moving... and half the time anything not moving. At one point I was shooting talking heads and the AF would randomly focus on the background.

So you basically have to shoot by focussing manually. But then you run into the lens not being parfocal via the grip rocker. So now you can only use the zoom switch on the lens. But that completely negates the one handed quick change/run-n-gun advantage of the grip.

Added to all this is the fact that the AE can be a bit hit and miss. I really wish Sony (and others) would give us the option to have zones or weighting for the AE (even AF) like you get on DSLR's. In some scenarios centre weighting exposure would be a godsend.

Now I know that doing everything in manual is the 'proper' way to make videos and if you have a controllable environment that's how to achieve the best outcome. But there is definitely a place for good auto systems that will give you usable shots 85% of the time.

Sometimes I'm required to shoot under the radar abroad or in environments where you need to grab shots quickly out on the street before the subjects notice you're filming them and the whole dynamic changes. In these scanarios you don't have time for manual, you just need damn good auto.

One of the best camcorders I've ever used for this type of work is the Canon XF305. I've acquired shots with it (in reasonable light) that no other camera has allowed previously. So some 4 years of progress later I was hoping the FS5 would be nearly as good. I accept it might not be as good re AF due to chip size/DOF etc. But I was at least hoping for decent AE and an AF system that is better than my DSLR's when shooting video. Even the image stablisation on the FS5 isn't as good IMO as the XF305 (once it's got a lock). And yes I do know they are two different types of camera, but Sony seems to be trying to market the FS5 into a similar corporate/doco/run-n-gun sector.

Anyway I'm having a bit of a rant because the FS5 was not fun to work with this weekend. I'm certain I'll enjoy it's other strengths when I'm not doing run-n-gun. But I'll be a lot more forgiving if Sony just sort out the kit lens/rocker grip issue.... right now it sucks!

[Kevin Langdon]

That's very disappointing to hear about the focus issue with the rocker grip and the kit lens.
Does this problem happen with just this lens or are other Sony/different makes of zoom lenses affected too?
You'd like to think that if Sony is aware of this problem, then it would look to solve it with a firmware update?

[Doug Jensen]

Originally Posted by Nigel Davey

In these scanarios you don't have time for manual, you just need damn good auto.

Blasphemy!! Repent now and be saved.

[Jim Stamos]

ill certainly be asking about this at nab. but as long as sony is selling these cams so well, dont expect a fix for that lens.

[Kevin Langdon]

Whatever happened to products being fit for purpose?
Sony listened to the edge tearing & blocking issue and this resulted in a firmware upgrade.
Let's hope they can do the same regarding lens losing focus too.

[Dmitri Zigany]

The emount lenses aren't to be treated as old broadcast typ lenses where you zoomed in to set focus. Just use the magnification...

The way I use them (with my FS700) is that I have the camera in manual but with face detection activated. Then just hit push auto every time I want it to focus... Or I do it manually depending on situation. Works like a charm most of the time. (For people walking towards or away from camera it is usually too slow though)

[Nigel Davey]

Sorry Dmitri but why should we give away something that has become a standard for a reason, is better than your method due to less refocusing and, most importantly, is being marketed by Sony?

It should just work rather than finding workarounds or taking steps backwards.

[Jim Stamos]

Dmitry
That dosent work,once u set focus as u zoom out it loses focus.the stock lens is great if u do zero zooming period.
I plan on asking Sony about this at NAB,not that they're gonna do a thing.

[Docea Marius]

Jim Stamos..right, this thing happened to me at a wedding shooting.not normal thing to happen,lens set in manual mode I made zoom I lost the focus complete.

[Jim Stamos]

Sadly, sales are good on the cameras so no fix from sony