Focus is malfunctioning

Attila Cser · December 22nd, 2009, 04:26 AM

Quote:

Originally Posted by Attila Cser

According to Silver Support the cam is back and on Monday I'll get it.
Let's see what they've done with it......

Hi, just a quick update, the EX1 is back. I only had time to turn it on quickly. It looked nice and focus was functioning well again. Silver Support is doing the job it seems. They say that the cam got a "replaced the lens, and a firmware upgrade to version 1.14"

I hope that all my card combos I used earlier along SXS will continue to function.
Also I still have to find out what the new firmware has been bringing as well as the version number of the new lens.

Ed Kukla · December 22nd, 2009, 06:10 PM

This may or may not apply to the original topic here...

Be careful of how you execute backfocus with these cameras. Having anything in the forground or background MIGHT compromise the auto backfocus.

electronic backfocus is a real bad idea. I wish/hope sony would change the software to put that back into the hands of the operator.

Attila Cser · December 23rd, 2009, 06:08 PM

Quote:

Originally Posted by Attila Cser

Also I still have to find out what the new firmware has been bringing as well as the version number of the new lens.

new lens XT14X5.8AS-X8C

MXR card appears to be working fine ( SANDISK Ultra II 16GB class 4 loaded into) with the new firmware.

and by the way:
Merry Christmas for all DVinfo.net readers, members and admins from Santa's homeland :-)

Eddie Coates · December 28th, 2009, 04:59 AM

What I do NOT understand is why a major corporation would make a video camera that cost $6,500 USD that does not focus properly!

My SONY EX1 has had these focus issues from day one.
Sony wants to charge me more money to upgrade or fix a problem that they are responsible for?
No way will give Sony $1,700.00 to fix a camera they made poorly.
They will fix this problem at their cost, or I take them to court. One of the luxuries of living in the USA

Ivan Gomez Villafane · December 31st, 2009, 12:09 AM

Quote:

Originally Posted by Michael B. McGee

i may have had the same problem on a shoot this week. my normal procedure for focusing is similar to yours. i zoom all the way in on my subject, focus and then zoom out to compose the shot. during the shoot i would notice on our 17" Panasonic HD monitor that the image looked soft even though the "peaking" showed everything in focus and the "DoF bar" displayed exactly what the "peaking" was doing. on a couple of shots the subject was anywhere between 5-10 feet away, yet i had to set the focus, on the lens, 2-3 feet further than the actually distance of my subject. i didn't notice these issues when i was zoomed in, only on the "fully" wide shots.

is this a back focus issue?

one variable to consider is that i had a 1/8 Black Pro Mist filter in my mattebox.

I was running some low light gamma curves and gain tests + some detail tests and I decided to also do some focus tests because recently I shot some wide angle shots, one of them was out of focus and I really doubted it was my fault. While running these tests, something really NOT funny happened with my focus: the exact same thing you describe. The most fearsome thing is that this apparently happens only at full wide angle, which means the problem is nearly impossible to notice without using an HD monitor.
I would like to share with you a clip that I hope it will help to shed some light on this subject.

RapidShare Webhosting + Webspace

Technical specifications:

- Doug's PP + DETAIL ON + GAMMA3.
- F1.9, 180º, 1080/24p.
- XT14X5.8 lens.
- V1.11_0531 firmware.

What I did:

1) Zoom in on the clapperboard and focus.
-> 2) Zoom out and zoom in on the $100 Gift Certificate. NOTICE how the focus does some barely noticable funny stuff almost exactly when I start to zoom in.
3) Focus on the $100 Gift Certificate.
--> 4) Zoom out. NOTICE how the focus does the same funny stuff just before I reach maximum wide angle.
--> 5) Zoom in a little bit. NOTICE the funny stuff again as soon as I start to zoom in.
6) Zoom out to maximum wide angle again. There is no funny stuff to be seen, but focus is lost.

There is definately something going on here. But the most frustrating thing is that I have spent almost one hour trying to reproduce this same problem without success... ! ! !

I hope we can all share as much insight as possible so that we don't surprise ourselves when we see our wide angle shots in our computer monitors.

My sincere best new year wishes!

Ivan.

Marty Welk · December 31st, 2009, 09:05 PM

Ivan, i wonder if the funny focus issue There, has something to do with the funny lighting issue?
because the sony focus uses (something like) how sharp 2 pixels are next to eachother in contrast, (unlike WAY back when they used sound or light bounces to determine the distance from the subject)
The lighting is rapidly changing (the fan) , i could see where the sony focus alogrythm style could have some major issues trying to figure out what is sharp contrast between pixels and not?
With the light changing as the chip is scanned, it could make AUTO focusing even harder than it is.

We can get a total lack of a ability to AUTO focus correctally when a light is present in the screen area the sonys are trying to focus, because of the light smearing/jumping registers of the chip, it cannnot focus because the contrast doesnt get any better in one (focus) direction or the other. so the auto is incapable of focusing, and it must be adjusted manuely. (the sharper it gets, the worse the light is smearing about)

The sony always "rocked" the focus a bit when finding the best focus position, instead of seeing it is Focused close enough then stopping. Sort of like a human will do, rocking it in both directions then settling it in the center of the 2 soft locations.
with HD focus position is tighter, sony is doing it too slowly, and with less frames per second, the machine doesnt even have enough samples per second (24) to determine which is better. add in some strangeness occuring throwing off it's comparison samples, and the human is on thier own :-)

Ivan Gomez Villafane · January 1st, 2010, 06:26 AM

Of course! I agree...

...but I was on Full Manual!

Maybe I didn't understand something?

Happy new year!

Ivan.

Piotr Wozniacki · January 1st, 2010, 08:21 AM

Are you sure not even Manual Assist was on? This can introduce hunting as well (not in FULL manual, though)...

Ivan Gomez Villafane · January 1st, 2010, 09:09 AM

100%... I don't even move the ring unless I want to do some macro.

We could judge the fiability of the metadata (why it says ND1 if I didn't have any ND filter?), but I ran some tests, when ASSIST is ON FOCUS displays "Centered" (for me).

Matt Davis · January 1st, 2010, 09:17 AM

Quote:

Originally Posted by Piotr Wozniacki

This can introduce hunting as well (not in FULL manual, though)...

Just as an aside, I note that even in full manual, there's a group of elements (probably near the back) that are most definitely servo controlled. Try doing a crash zoom (using manual control), and watch the focus. You can see the servos fail to keep up and lose focus, then as you stop, the servos tug at something to sharpen up.

When JVC launched the HD100, it came with a Fujinon 'HD' (sic) lens that exhibited an effect known as 'Breathing' - as you focus, the image changes in size. In fact, the lens didn't breathe so much as 'gasp'. I believe that the EX1 lens, even in full manual mode, has some electronics to try and reduce this 'breathing' effect which is a tell-tale of a 'cheaper' or probably more accurately 'less sophisticated' lens.

So perhaps (as in 'I am not a lawyer, I am not a lens expert') there could be a fault with this part of the lens that's 'hunting' or 'fidgeting' even in full manual mode.

We're talking about a computer with a bit of glass at the front, so if a reboot, a Maintenance Mode backfocus and a full camera reset (followed by BF) doesn't clear it, then I guess it's a mechanical issue best cured by replacement.

Ivan Gomez Villafane · January 1st, 2010, 10:20 AM

I can fully vouch for what Matt said about the crash zoom focus issue, I have experienced it while shooting some 300-like action takes. I have a long render queue right now, but I will upload an example ASAP.

Regarding my "funny focus" issue, I'm kind of afraid to touch anything serious, I don't have Sony next door to go knock in case something goes wrong... but do you believe doing a BF should fix my problem?

Alister Chapman · January 1st, 2010, 01:27 PM

The focus on the EX camera is completely electronic. There is no mechanical connection between the focus ring and the lens elements.

Traditional manual zoom ENG lenses, like the one supplied with the JVC HD100 use very complex combinations of lens elements that are mechanically connected together and move by different amounts relative to each other through the zoom range. This is done so that the focus remains constant through the zoom range. It's very difficult to get right and wear and tear of the cams and guides can lead to poor performance and collimation errors, it also requires a lot of lens elements some of which may need to be made from some very exotic types of glass. Focus itself is done by moving the front lens element forwards and backwards. The forwards and backwards movement by several mm of the front element is what introduces breathing as this slightly changes the focal length of the lens.

The lenses on most home video cameras and the majority of semi-pro cameras are of a much simpler and thus cheaper design with fewer elements that does not maintain the same focus distance throughout the zoom range (varifocal zoom). To make these usable for video an electronic look-up table is used that compensates for changes in focus by electronically adjusting the rear lens element as you zoom. On the EX cameras (and many other small camcorders) the lens is also focussed by adjusting the rear element electronically according to the look-up table. Because the rear element only moves by a tiny amount there is almost no breathing. Fewer elements means lower cost and reduces the need for expensive exotic glass. There is no breathing and the lens can be setup and calibrated electronically.

This technology is creeping in to high end lenses as well as low cost lenses as any mechanical wear can be programmed out of the lens and it makes larger zoom ratios possible. It may be that in the future all zoom lenses will adopt this technology as it makes the optical design of the lens much simpler which should lead to better image quality at lower cost.

I have had to re back focus my EX1 and EX3 from time to time. Rough handling by airline baggage handlers has upset my EX1 on a couple of occasions. I always use a flat wall with the camera perpendicular to it about 8ft away. Any type of patterned wall paper, textured wall covering or brickwork seems to work just fine.

Matt Davis · January 1st, 2010, 02:21 PM

Great insight, thanks Alister!

Quote:

Originally Posted by Alister Chapman

I have had to re back focus my EX1 and EX3 from time to time. Rough handling by airline baggage handlers has upset my EX1 on a couple of occasions.

That's very reassuring - in that it's not a sign of i) impending doom or ii) the feeling of Camera Hypochondria. Just maintenance.

Piotr Wozniacki · January 1st, 2010, 03:28 PM

Quote:

Originally Posted by Alister Chapman

I have had to re back focus my EX1 and EX3 from time to time. Rough handling by airline baggage handlers has upset my EX1 on a couple of occasions. I always use a flat wall with the camera perpendicular to it about 8ft away. Any type of patterned wall paper, textured wall covering or brickwork seems to work just fine.

Alister,

Just wanted to make sure: is it enough to do it once, or is it necessary to repeat the procedure for each position of the ND filter switch?

Ian Campbell · January 1st, 2010, 05:12 PM

Quote:

Originally Posted by Alister Chapman

I have had to re back focus my EX1 and EX3 from time to time. Rough handling by airline baggage handlers has upset my EX1 on a couple of occasions. I always use a flat wall with the camera perpendicular to it about 8ft away. Any type of patterned wall paper, textured wall covering or brickwork seems to work just fine.

Hi, Alister . . .

Sounds like great info. to know about. I have two EX1's which seem to be focusing fine. In the event I need to shoot a textured wall, etc. to help regain proper back focus, what is the procedure? Since there are no user adjustable controls for back-focus on the fixed lens EX1 how does one make back focus improvements the camera will store and remember?

Many thanks . . .

Ian

December 28th, 2009, 04:59 AM	#34
Eddie Coates Regular Crew Join Date: Jun 2008 Location: Scottsdale, AZ Posts: 58	What I do NOT understand is why a major corporation would make a video camera that cost $6,500 USD that does not focus properly! My SONY EX1 has had these focus issues from day one. Sony wants to charge me more money to upgrade or fix a problem that they are responsible for? No way will give Sony $1,700.00 to fix a camera they made poorly. They will fix this problem at their cost, or I take them to court. One of the luxuries of living in the USA __________________ SONY EX1, (Vista Ultimate 64bit, i-7 core processor, 12gigs of DDR3, ATI 5870 GPU Adobe CS4) Canon 5DMkII and Canon 7D 70-200mm 2.8L IS, Tamron 28-75mm 2.8 XR Di

December 31st, 2009, 09:05 PM	#36
Marty Welk Major Player Join Date: Sep 2008 Location: East Bay Cali Posts: 563	Ivan, i wonder if the funny focus issue There, has something to do with the funny lighting issue? because the sony focus uses (something like) how sharp 2 pixels are next to eachother in contrast, (unlike WAY back when they used sound or light bounces to determine the distance from the subject) The lighting is rapidly changing (the fan) , i could see where the sony focus alogrythm style could have some major issues trying to figure out what is sharp contrast between pixels and not? With the light changing as the chip is scanned, it could make AUTO focusing even harder than it is. We can get a total lack of a ability to AUTO focus correctally when a light is present in the screen area the sonys are trying to focus, because of the light smearing/jumping registers of the chip, it cannnot focus because the contrast doesnt get any better in one (focus) direction or the other. so the auto is incapable of focusing, and it must be adjusted manuely. (the sharper it gets, the worse the light is smearing about) The sony always "rocked" the focus a bit when finding the best focus position, instead of seeing it is Focused close enough then stopping. Sort of like a human will do, rocking it in both directions then settling it in the center of the 2 soft locations. with HD focus position is tighter, sony is doing it too slowly, and with less frames per second, the machine doesnt even have enough samples per second (24) to determine which is better. add in some strangeness occuring throwing off it's comparison samples, and the human is on thier own :-) __________________ ----------------sig----------------- Re-learning everything all over again, one more time.

January 1st, 2010, 08:21 AM	#38
Piotr Wozniacki Inner Circle Join Date: Aug 2006 Location: Poland Posts: 4,086	Are you sure not even Manual Assist was on? This can introduce hunting as well (not in FULL manual, though)... __________________ Sony PXW-FS7 \| DaVinci Resolve Studio; Magix Vegas Pro; i7-5960X CPU; 64 GB RAM; 2x GTX 1080 8GB GPU; Decklink 4K Extreme 12G; 4x 3TB WD Black in RAID 0; 1TB M.2 NVMe cache drive

January 1st, 2010, 09:09 AM	#39
Ivan Gomez Villafane Regular Crew Join Date: Aug 2009 Location: Buenos Aires, Argentina Posts: 73	100%... I don't even move the ring unless I want to do some macro. We could judge the fiability of the metadata (why it says ND1 if I didn't have any ND filter?), but I ran some tests, when ASSIST is ON FOCUS displays "Centered" (for me). Attached Thumbnails

January 1st, 2010, 01:27 PM	#42
Alister Chapman Inner Circle Join Date: Dec 2005 Location: Bracknell, Berkshire, UK Posts: 4,957	The focus on the EX camera is completely electronic. There is no mechanical connection between the focus ring and the lens elements. Traditional manual zoom ENG lenses, like the one supplied with the JVC HD100 use very complex combinations of lens elements that are mechanically connected together and move by different amounts relative to each other through the zoom range. This is done so that the focus remains constant through the zoom range. It's very difficult to get right and wear and tear of the cams and guides can lead to poor performance and collimation errors, it also requires a lot of lens elements some of which may need to be made from some very exotic types of glass. Focus itself is done by moving the front lens element forwards and backwards. The forwards and backwards movement by several mm of the front element is what introduces breathing as this slightly changes the focal length of the lens. The lenses on most home video cameras and the majority of semi-pro cameras are of a much simpler and thus cheaper design with fewer elements that does not maintain the same focus distance throughout the zoom range (varifocal zoom). To make these usable for video an electronic look-up table is used that compensates for changes in focus by electronically adjusting the rear lens element as you zoom. On the EX cameras (and many other small camcorders) the lens is also focussed by adjusting the rear element electronically according to the look-up table. Because the rear element only moves by a tiny amount there is almost no breathing. Fewer elements means lower cost and reduces the need for expensive exotic glass. There is no breathing and the lens can be setup and calibrated electronically. This technology is creeping in to high end lenses as well as low cost lenses as any mechanical wear can be programmed out of the lens and it makes larger zoom ratios possible. It may be that in the future all zoom lenses will adopt this technology as it makes the optical design of the lens much simpler which should lead to better image quality at lower cost. I have had to re back focus my EX1 and EX3 from time to time. Rough handling by airline baggage handlers has upset my EX1 on a couple of occasions. I always use a flat wall with the camera perpendicular to it about 8ft away. Any type of patterned wall paper, textured wall covering or brickwork seems to work just fine. __________________ Alister Chapman, Film-Maker/Stormchaser http://www.xdcam-user.com/alisters-blog/ My XDCAM site and blog. http://www.hurricane-rig.com

December 22nd, 2009, 06:10 PM	#32
Ed Kukla Major Player Join Date: Mar 2008 Location: All over, USA Posts: 512	This may or may not apply to the original topic here... Be careful of how you execute backfocus with these cameras. Having anything in the forground or background MIGHT compromise the auto backfocus. electronic backfocus is a real bad idea. I wish/hope sony would change the software to put that back into the hands of the operator.

January 1st, 2010, 06:26 AM	#37
Ivan Gomez Villafane Regular Crew Join Date: Aug 2009 Location: Buenos Aires, Argentina Posts: 73	Of course! I agree... ...but I was on Full Manual! Maybe I didn't understand something? Happy new year! Ivan.

January 1st, 2010, 10:20 AM	#41
Ivan Gomez Villafane Regular Crew Join Date: Aug 2009 Location: Buenos Aires, Argentina Posts: 73	I can fully vouch for what Matt said about the crash zoom focus issue, I have experienced it while shooting some 300-like action takes. I have a long render queue right now, but I will upload an example ASAP. Regarding my "funny focus" issue, I'm kind of afraid to touch anything serious, I don't have Sony next door to go knock in case something goes wrong... but do you believe doing a BF should fix my problem?