Serious Backfocus Problems on Sony EX3

[John Cookman]

Richard, I have been going through some serious focus issues with my EX-3. I have read in a couple of places that this was also an issue with the EX-1. We have talked to sony and they gave us a few things to do with in the camera to help correct the back focus respond better. We have executed these tips but it didn’t help.

I find that when the camera gets out of focus (usually in a close up shot or a really wide shot) that if we turn the camera off and then back on it will be perfectly in focus when it restarts. I don’t know if this is exactly what is happening with yours but I think that your resolution to this problem may be exactly what we need as well.

The Next step for us is to send the camera to Sony. Do you have any other ideas on how we may be able to fix this problem without sending it back.

Do you think this problem is in the camera or the lens? The problem is only in the included Fujinon Lens. We have a Manual 18X Studio lens that we use on it as well and there are no problem when I use ths lens.

[Thomas Kist]

I’ve had the same problem with my EX-3.
It took a very long time to convince the people at Sony’s repair center in Basingstoke UK that there was a real problem.
Only after sending over video clips showing the problem and getting very angry did they respond.
In the end they changed the lens and that solved all the problems.
At first they try to make an amateuristic idiot out of you.
Don’t let that happen, there is a serious design problem with the electronics that control the lens back focus. But Sony does not want to discuss that.
They did that before, and its stupid because camera’s like the EX-3 are not made for the ignorant home video crowd.
A professional camera system with international prime support deserves a professional response.

Thomas Kist
Freelance D.o.P
Amsterdam,The Netherlands
PDW-700,EX-3&Letus,FCP 6
http://www.thomaskist.com

[John Cookman]

Thomas, thank you so much for your post and supportive tip on handling Sony. Luckily, they have been responsive because we communicated with them the settings in which we used it. We Broadcast Globally 5 times a week. We have been an all Sony operation for 5 years using their high end SD cameras, shading, painting, and switching solutions.

I am thinking I want to make my new HD studio an EX-3 (3 camera) package but if they can’t get the lens problem worked out then I may have to rethink my options. Sony has been good for us so I do want to give them every chance to make this right.

Sorry to hear about your problems with them but, has the new lens given you any problems?

Thanks again,
John Cookman

[Richard Ladkani]

Hi all,

The lens is not the problem. I checked with two different standard lenses and also with the wideangle lens rom Fujinon. And I checked all three lenses on two different EX3 cameras. I checked all that at the Sony Center Munich together with 3 technicians from Sony. We got the same problem an all lenses and both cameras.

Here is what we saw and how we tested:

You set everything to manual and open the iris to wide open. Then zoom in on a siemens chart about 7 feet away. Focus the chart then slowly zoom out and check what happens with the siemens chart. It will go out of focus ever so slightly and reach its worst out of focus when totally wide. Then you switch to pixel to pixel on an HD monitor. Best a 17″ model. You will see a slightly blurred siemens chart. When you now start dialing the focus ring on the camera towards 3 feet you will see the chart get sharper. It was sharpest between 3-4 feet. We repeated this test at least 15 times and then also checked it through an electronic device that reads sharpness and contrast and looks like a waveform. This is what finally confirmed the problem for Sony to be a Backfoucs problem of the camera not the lens.

Remember the lens aperture has to be wide open the distance to the chart about 7 feet and of course everything set to manual.

Also I want to stop this badmouthing Sony. The team in Munich was fantastic. Only the Sony support in London didn’t want to listen and didn’t want to cooperate. They just did there standard tests and didn’t want to test the camera the way I did. So they never saw the problem.

If any body out there could repeat my test and tell me what they saw it would be great.

I do have a hunch where the problem originates:
I think it has something to do with how you set up lighting, distance of the chart and what else is visible in the frame when you run the “Adjust Backfoucs” in the camera. We got slightly different degrees of the problem when we changed all the above. But this would be a hue problem because I usually have to adjust backfocus whenever I change the lens in the field which could be anywhere and is certainly not a lab or a studio environment.

All the best
Richard

https://www.richardladkani.com

[Rick Diamond]

I had the same back focus problem…Exactly the same, actually. Sony ended up replacing my lens. The new one is fine.

[Richard Ladkani]

I checked this problem on two standard lenses and the wide angle and always got exactly the same off backfocus. And then I checked with a different EX3 at the Sony Center and got the same off focus. Very strange that a replacement lens fixed your problem. Our realization was that it must be a flaw with all EX3 cameras. That’s why they forwarded the problem to Sony Japan. But they never reacted. So I turned to this forum to see who else has a backfocus problem…and see what can be done.

https://www.richardladkani.com

[Chris Cardno]

We have an EX3 but haven’t run into this issue — however, the Z7U that we HAD did have this problem and we were certainly not alone. Same issue: set the backfocus, zoom out, focus would drift and the shot would be soft. We just had the camera replaced (as did another company in town, both of their Z7Us displayed the problem right out of the box) and the new camera doesn’t have the drifting issue.

Odd to see the same problem across model lines from the same manufacturer…

Chris Cardno
Visual Edge Productions
Bethesda, MD

[Richard Ladkani]

I might have found the cause of the problem. And it’s pretty serious that nobody picked up on it.

We are shooting right now with an EX3 in Rome and the backfoucs poblem became so severe we couldn’t continue shooting with it anymore. When zooming in and setting focus on a chart about 7ft away and then zooming out to wide angle the focus went soft. When turning the focus to about 3ft it became sharp again while in wide angle. Same problem on the fujinon wide angle. We redid the back foucs again and again with different size charts it stayed totally off. Then we drove to a rental house and compared our EX3 with a second EX3. SAME PROBLEM. The other EX3 was also off. The guys at the rental house couldn’t believe it. So we all tried to figure out the problem and finally found a possible SOLUTION.

The camera has a software bug. When setting the backfocus you have to FISRT reset Camera Data to factory settings. Then you run the backfocus and then it actually works. When we then did the back focus a second time WITHOUT resetting the cameras it was off again almost to an identical level on BOTH cameras. We then reset both cameras again did the backfoucs again and then it worked on BOTH cameras without problem.

We do hope we finally resolved this issue for good but I find it amazing that nobody picks up on it and complains. Doesn’t anybody check their backfocus?? It’s a reall sony bug that you have to reset camera data before performing the back focus. It’s not written in the manual, no sony technician told me about this although it’s crucial.

We do hope it’s resolved now. Will keep shooting throughout the week. If problems persist will let you know.
Best
Richard

https://www.richardladkani.com

[Sarmad Hama]

hi richard ladkani;
did you fixed the probleme that (when you want shooting open iris low light scenes) pleas if you do , send me the solution of this problem
to this E_mail (sarmadmah2004@yahoo.com)
best regards

[Clodomiro Luque]

Hi, did you ever get an answer to the back focus problem with open iris?
rgds
Clodo