Then, a day after my writeup hit the web, filmmaker Lenny Levy sent me an email: “My back-focus goes out whenever I engage the ND filters!” He said various people on DVInfo.net and DVXUser.com had observed the same thing.
The problem is most apparent at wide lens apertures; as the lens stops down, it becomes less and less noticeable.
When we had moved outside during the Videofax test, I switched to ND Filter 1 or 2, to keep aperture at F2.8. I zoomed in to focus on Tim, sitting about 10 feet away, but when I pulled back to 17mm the focus shifted to the back wall of the garden perhaps 25 feet away, and Tim went soft instead of the background:
The good news? I can stop beating myself up for blowing focus on an easy shot. The bad news? I can start beating myself up for not checking back-focus more carefully!
In my testing today, I didn’t see any obvious difference in the back-focus setting when I switched between ND filters 1 and 2, but I did see it change quite a bit when I switched between “off” and either 1 or 2.
I don’t know if this is something that affects all EX1s, or just a limited number. Don’t assume yours has any issues without running your own tests.
The first two options should be self-explanatory. The last one needs some discussion.
This isn’t great news. I’m planning on buying one of these, perhaps even today. I’ve wrestled with the rolling shutter, and ergonomics, but this is kinda big. I have to tell you, I’m still coming down on the side of buying one, but It would assuage my troubled soul muchly if others sounded off and said that they didn’t have a problem. This sounds like something that:
a-sony will fix. even if you already own it.
b- a problem with early adopters, like the intrepid Adam that they may have already fixed.
At the end of the day, it’s non-trivial. I use (and overuse) NDs on cams to open up the iris to get depth of field.
Wow, the Panny fan boys are gonna have a field day with this. heh.
Posted by on 03/21 at 07:41 AM
Thanks very much Adam, for testing the focus and suggesting fixes, much appreciated.
I just bought my unit yesterday and will test it under the conditions you stated.
I also hope that if there is a problem Sony will fix it.
Your right that the good news, is that it is workable, though its a shame to have to sidestep the ND for front of lens options.
I think that a new camera at this price level should not have this problem.
AND yes, the panasonic people are going to have a field day with this news.
I pray that your last statement holds true,
“At least your not stuck with bad back-focus”
Posted by on 03/21 at 10:44 AM
Please excuse my ignorance, I’m still a newbie with the EX1. But I’m not sure I understand the problem here. Does the back-focus go out only when you SWITCH from no ND filter to ND filter after focusing, or vice versa? In other words, if you focus with the ND filter on and then zoom out, does it stay in focus or “go soft”?
Posted by harryllama on 03/21 at 10:51 AM
“a problem with early adopters, like the intrepid Adam that they may have already fixed.”
The last time I checked, they hadn’t fixed me, but if you hear me singing castrato, you’ll know they have. <grin>
“Does the back-focus go out only when you SWITCH from no ND filter to ND filter after focusing, or vice versa? In other words, if you focus with the ND filter on and then zoom out, does it stay in focus or ‘go soft’?”
If the camera is calibrated with ND off, back-focus will be correct with ND off, and (if your camera has this problem to begin with) wrong whenever the ND filter(s) are used. It’s not throwing the switch that does it, it’s the presence of the filter in the optical path. In this case, if you focus with the ND filter on and then zoom out, it’ll ‘go soft’ (push the focal point back towards infinity).
For the purposes of this discussion, back-focus adjustment governs the ability of the lens to hold focus during zooming. If you focus at your final zoom setting, you’ll be OK, but many people like to zoom in to focus for the greater sensitivity it gives you. If you zoom with bad back-focus, your focal point will shift during the zoom.
And if you calibrate the camera with ND on, it’ll track properly as long as ND is on--even if you switch it off, then on again.
It sounds like a horrible problem, and the fix sounds onerous, but (a) it’s unknown if this is a widespread issue or not and (b) it’s really not as bad as it sounds. Yes, it’s an annoyance; no, it doesn’t cripple the camera. It’s like the funky knee behavior or the off-center handgrip or the “tetchy” power switch: an idiosyncrasy you have to trade off against what the camera can do for you.
Let he who builds a camera without sin cast the first stone… all cameras at these price points have tradeoffs!
Posted by Adam Wilt on 03/21 at 12:56 PM
Hi Adam and company:
This is a known issue with the EX-1. I own the HVX and have been considering buying an EX-1 but I must say that all of the initial factory defects are giving me second thought. I am not a fan boy of either camera honestly, they are both tools that are better in certain areas.
But based upon the vignetting debacle, the chromatic aberration issues that some users are seeing and now this, I would surmise that in their rush to beat Panasonic from selling so many HVXs, they rushed this product through the QC and refinement phase of manufacturing and design.
There are several elements of the product’s design that are just plain stupid, which is not unusual for under $10,000.00 camcorders from any of the manufacturers. The poorly located USB port, the paint that is flaking off of the body along with the silk screened labeling, etc.
I shot with an EX-1 the other day, the picture is truly breathtakingly good but all of the other issues are causing me to really debate about whether I should buy one or wait for the HVX-300 or whatever Panasonic will call it. You know that within a year, Panasonic will introduce a camera that will be under $10,000.000 and will beat the EX-1 or will at least be it’s equal but with the DVCProHD and possibly AVC Intra codecs aboard.
Tough choices out there, but I agree, the EX-1 is a great product but you are paying the price to be on the bleeding edge.
Dan Brockett
Posted by on 03/21 at 03:16 PM
I’ve carefully tested my EX1 camera’s back focus using f1.9 with ND OFF, ND1, and ND2. I used higher shutters speeds to maintain the open apeture.
I’m not seeing a difference with ND filters on or off.
This tells me there must already be some compensation for back focus using the ND filters, although I need help at understanding why this would be an issue. In the past, I have not see an ND filter affect focus. Maybe it’s dependent where the ND filter is placed in the optical path.
I’m not sure why some EX1 cameras have this issue, and some don’t. Why is Sony failing with their QC department. I’m on my second camera that still has the known vignetting issue. My first camera came back not fixed.
I’m to dang scared to send it in. If I send it in, it may come back with worse vignetting, or the same. Worst yet, it may come back with a back focus issue which happened to another user recently.
I’m praying Sony sets it straight for all us who did not realize we were their prototype testers.
Steve
Posted by on 03/24 at 12:41 PM
Where is the maintenance menu for setting back focus? I would like to check to see if my new EX-1 is problematic as well.
Posted by on 03/24 at 01:03 PM
Sorry… missed the second page of this post. Thanks for all of the info you are providing on this camera.
Posted by on 03/25 at 12:00 PM
Adam,
There’s another EX1 owner who has been able to adjust BF on all ND positions and off with success.
He tested it with software version 1.03 and 1.05, they both worked and is sharp on all conditions.
He did mention he set up 12, A4 BF charts (i’m assuming siemens star) side by side in a 4 column, three row arrangement on a blank wall at 10 ft with nothing in view at full wide other than the charts. Apeture f1.9.
He has been going back and forth with Sony with no luck. His loaner was also bad.
Just when he was about to call it quits, he tried the adjustment with the above configuration.
He said even the loaner camera is now fixed. Focus is now sharp regardless on ND condition. He also mentioned that Sony service was not able to fix his issue.
This is interesting. Any thoughts?
thread:
http://dvinfo.net/conf/showpost.php?p=849934&postcount=29
Posted by on 03/28 at 08:54 AM
How can you tell which software version your EX1 is running and can it be ungraded if it’s an older version?
TIA
Posted by on 03/28 at 10:42 PM
Steve: Thanks! I tried this (with a BIG Siemens Star, shot with my HVX200 and displayed on my 40” LCD with no other light in the room, grin). I found no initial difference, but after running the adjustment several times, and running it with the filter in each of the three positions, our EX1 got a lot better: back-focus is perfect with ND off, and with it on, back-focus shifts just slightly back as I zoom out: not enough to blur the subject, but so that the in-focus area starts just in front of my subject and extends back, instead of being centered on my subject.
In other words, it’s good enough to be usable without having to refocus, even with NDs engaged.
I don’t know if it was (a) the large bright target, (b) repeated readjustment, and/or (c) doing all three filter positions one after the other that made the back-focus better, but it *is* better, now. And the improvement has lasted for a full day and across three battery changes.
I’m running firmware version 1.03.
Luc: to see the firmware version, open the service menu as described on page 2, and scroll down the left side to the IF ("information") selection.
I’ll update the article with this info.
Posted by Adam Wilt on 03/29 at 07:16 PM
Adam,
thanks for the follow up.
Like you mentioned, it makes me wonder if you have to run through all three ND settings for it to take correctly.... Seems odd it would, but you never know.
Well, seeing we know the combo of a large target with nothing else in view when wide, and setting all three ND conditions, it appears this method should work for us.
It’s odd that a lot of these cameras were released with BF not setup.
Steve
Posted by on 03/30 at 08:22 AM
