Z1U backfocus out? anyone else with the problem at DVinfo.net

Colin McAuliffe · January 25th, 2008, 10:31 PM

OK,

I'm just curious. Am I the only Z1u owner who's focus sucks on that camera? I'm used to broadcast lenses and the DVX/HVXs where you can push all the way in, pull your focus, the pull out and you are fine anywhere within your zoom range once you have that critical focus.

However, with my Z1u, that is not the case, If i zoom all the way in, focus, and pull out, I am not sharp.

whatsupwiththat? Is that all Z1Us or just mine?

-C

Zach Stewart · January 26th, 2008, 01:01 AM

We have 4 - Z1U's at work and they all do the same thing...I do not use the "backfocus" anylonger with the Z1U it comes up too soft and never works like it should. I wonder if this has something to do with the chip size if not then why does it do that...

Carl Middleton · January 26th, 2008, 09:12 AM

I've never had a single problem with backfocus on my Z1, it works like any camera should in that regard... But if it's giving you serious trouble, try the focus assist? 101 ways to do the job. :)

Carl

Colin McAuliffe · January 26th, 2008, 12:33 PM

ok, i think I probably shouldn't have used the term 'backfocus'.

My real question is weather or not all Z1Us will not keep the same focus point throughout the full range of the zoom. Ie. if i focus when i'm pushed in, I'm not in focus when i pull out.

The reason i ask this is because i'm trying to figure out if i need to send my rig in for repair or not.

Carl Middleton · January 26th, 2008, 03:09 PM

I can't say for sure, but it sounds like you might.

In hundreds of hours of tape run on my camera doing nature/adventure/etc video plus a good bit of corporate and cinematic, I have never once had a problem with the good old zoom in, focus, zoom out method of focusing....

Graeme Fullick · January 26th, 2008, 03:19 PM

Just did a test with my Z1 using a back focus chart and peaking to check the focus point. The focus held perfectly from full telphototo to wide angle right in the centre of the chart - the peaking indicator stayed right in the middle for the whole pull back.

My conclusion is that my Z1 does hold focus perfectly - so it is likley that yours is not adjusted correctly

Eric Lagerlof · January 27th, 2008, 02:31 AM

There is mention in the EX-1 forum of backfocus adjustments via a service menu on the Sony EX-1. I wonder if there is not an equivalent sevice menu and/or adjustment with the Z-1/FX-1?

Colin McAuliffe · January 28th, 2008, 11:39 AM

its funny,

i just checked the cam with a backfocus chart and it seems fine. the chart blooms throughout the whole zoom range. I'm thinking it might just be that I'm zooming in and focusing on people that are standing too close to the lens maybe? perhaps when you are within 2 meters it does a macro focus? I dunno, i guess ill have to check it some more with bigger targets, like humans.

Carl Middleton · January 28th, 2008, 11:51 AM

Oh, THAT!

I've had that happen, when zooming to 99 on a static object at about 3 feet. I said screw it and made an artsy montage using the effect. Worked well.

But yes, I have seen that. It'll hold the focus on the object, allowing you to zoom out (and it loses focus) and back in (and it snaps back in focus) correct?

I'm assuming that is a macro focus or something crazy, but yes, at full zoom on a close object, I have seen an effect similar to your description. I assumed you were talking about zooming into a face to set your focus, etc. Sorry.

C

Colin McAuliffe · January 28th, 2008, 11:54 AM

alright,

I think i actually figured it out. I guess since i do so much low-light work with this camera (mostly press events at dark venues with a litepanel on the cam) I was always shooting with an open iris (1.6). then, when i push all the way in and focus, the iris is close down to a 2.8.

does that make sense? it seems that when i test with a chart at 4.0 I have no focus issues whatsoever.

I think that the iris and macro issues together, are what were causing the problems

Matt Davis · January 28th, 2008, 04:58 PM

Quote:

Originally Posted by Colin McAuliffe

I think that the iris and macro issues together, are what were causing the problems

Possibly.

My first Z1 seemed soft, and I'm pretty sure now that it may have had a back focus issue. I didn't trust it and was forever fiddling with focus and feeling sick about it.

Luckily (?) it was stolen. The new Z1 can be zoomed in, focussed, zoomed out and it's still sharp - rinse and repeat - the lens holds focus.

I guess there are some Friday Afternoon Z1s out there, simply because of the volume in which they're made.

January 25th, 2008, 10:31 PM	#1
Colin McAuliffe Regular Crew Join Date: Nov 2005 Location: San Francisco, CA Posts: 71	Z1U backfocus out? anyone else with the problem OK, I'm just curious. Am I the only Z1u owner who's focus sucks on that camera? I'm used to broadcast lenses and the DVX/HVXs where you can push all the way in, pull your focus, the pull out and you are fine anywhere within your zoom range once you have that critical focus. However, with my Z1u, that is not the case, If i zoom all the way in, focus, and pull out, I am not sharp. whatsupwiththat? Is that all Z1Us or just mine? -C

January 26th, 2008, 09:12 AM	#3
Carl Middleton Major Player Join Date: Sep 2007 Location: Fernandina Beach, FL Posts: 562	I've never had a single problem with backfocus on my Z1, it works like any camera should in that regard... But if it's giving you serious trouble, try the focus assist? 101 ways to do the job. :) Carl __________________ Carl Middleton Whizkid Mediaworks

January 26th, 2008, 03:09 PM	#5
Carl Middleton Major Player Join Date: Sep 2007 Location: Fernandina Beach, FL Posts: 562	I can't say for sure, but it sounds like you might. In hundreds of hours of tape run on my camera doing nature/adventure/etc video plus a good bit of corporate and cinematic, I have never once had a problem with the good old zoom in, focus, zoom out method of focusing.... __________________ Carl Middleton Whizkid Mediaworks

January 26th, 2008, 03:19 PM	#6
Graeme Fullick Major Player Join Date: Mar 2005 Location: Newcastle, Australia Posts: 337	Just did a test with my Z1 using a back focus chart and peaking to check the focus point. The focus held perfectly from full telphototo to wide angle right in the centre of the chart - the peaking indicator stayed right in the middle for the whole pull back. My conclusion is that my Z1 does hold focus perfectly - so it is likley that yours is not adjusted correctly __________________ Graeme

January 28th, 2008, 11:51 AM	#9
Carl Middleton Major Player Join Date: Sep 2007 Location: Fernandina Beach, FL Posts: 562	Oh, THAT! I've had that happen, when zooming to 99 on a static object at about 3 feet. I said screw it and made an artsy montage using the effect. Worked well. But yes, I have seen that. It'll hold the focus on the object, allowing you to zoom out (and it loses focus) and back in (and it snaps back in focus) correct? I'm assuming that is a macro focus or something crazy, but yes, at full zoom on a close object, I have seen an effect similar to your description. I assumed you were talking about zooming into a face to set your focus, etc. Sorry. C __________________ Carl Middleton Whizkid Mediaworks

January 26th, 2008, 01:01 AM	#2
Zach Stewart Regular Crew Join Date: May 2007 Location: Dallas, Texas Posts: 176	We have 4 - Z1U's at work and they all do the same thing...I do not use the "backfocus" anylonger with the Z1U it comes up too soft and never works like it should. I wonder if this has something to do with the chip size if not then why does it do that...

January 26th, 2008, 12:33 PM	#4
Colin McAuliffe Regular Crew Join Date: Nov 2005 Location: San Francisco, CA Posts: 71	ok, i think I probably shouldn't have used the term 'backfocus'. My real question is weather or not all Z1Us will not keep the same focus point throughout the full range of the zoom. Ie. if i focus when i'm pushed in, I'm not in focus when i pull out. The reason i ask this is because i'm trying to figure out if i need to send my rig in for repair or not.

January 27th, 2008, 02:31 AM	#7
Eric Lagerlof Major Player Join Date: Mar 2004 Location: Pacifica, CA Posts: 348	There is mention in the EX-1 forum of backfocus adjustments via a service menu on the Sony EX-1. I wonder if there is not an equivalent sevice menu and/or adjustment with the Z-1/FX-1?

January 28th, 2008, 11:39 AM	#8
Colin McAuliffe Regular Crew Join Date: Nov 2005 Location: San Francisco, CA Posts: 71	its funny, i just checked the cam with a backfocus chart and it seems fine. the chart blooms throughout the whole zoom range. I'm thinking it might just be that I'm zooming in and focusing on people that are standing too close to the lens maybe? perhaps when you are within 2 meters it does a macro focus? I dunno, i guess ill have to check it some more with bigger targets, like humans.

January 28th, 2008, 11:54 AM	#10
Colin McAuliffe Regular Crew Join Date: Nov 2005 Location: San Francisco, CA Posts: 71	alright, I think i actually figured it out. I guess since i do so much low-light work with this camera (mostly press events at dark venues with a litepanel on the cam) I was always shooting with an open iris (1.6). then, when i push all the way in and focus, the iris is close down to a 2.8. does that make sense? it seems that when i test with a chart at 4.0 I have no focus issues whatsoever. I think that the iris and macro issues together, are what were causing the problems