Caveat: I come from the broadcast world and have over a decade of setting backfocus of true broadcast lenses from Betacam SP/SX/DigiBeta to DSR300 DVCams up to my recently disposed of JVC GY-HD200ub cameras with Fujiunon zooms. I understand the process.

So, I have repeatedly used the Auto Flangeback Adjust function on my 2 month old PMW200 with Siemens Star charts up to 20" x 30".

Wide open to f2.8, when I focus on an object at full telephoto and start to creep back in zoom, the focus point CHANGES to a point in front of the "tacked up" focus point.

At this point, this camera is very nearly unusable to me.

I'm setting AFB with a clean, well lit high contrast target of adequate size at EXACTLY 10' from front of lens on a clean featureless wall.

Help!

Addendum: this is with the lens "clicked" into MF manual focus, non-servo focus mode.

I always thought distance was measured from the plane of the image sensor to the subject, not from the front of the lens to the subject. Am I wrong?

Unfortunately there are no other settings you can try so if the ABF routine isn't correcting the problem then the camera needs a trip to Sony for a repair.

That is a servo driven lens so there could be a problem with its calibration. That has to be done at a service center.

Warren: the 10 foot reference was for the Auto Flange Back adjustment. I don't use physical measurements for focus while shooting - I use the zoom-tack-up and/or Peaking/Expanded Focus methods.

Any further than 10 feet, the Back Focus chart becomes quite small at the wide angle view while performing the AFB adjustment so I want to work as CLOSE as I can to provide an adequate chart size but far enough away to actually be able to perform the adjustment.

The ONLY thing I just noticed is that in the END of the manual (not where it tells you how to perform the procedure, which I follow to a T) it suggests that the camera should be in 59.94i mode. I've been performing it at 29.97P or 23.98P. I'll double check that later today.

For your information, here is the page that details the procedure:

My experience with the auto flange back routine is that it doesnt work well with a seimens chart and you want to be at least 10ft from the target. I tend to use a brick wall or wall with a patterned wall paper. The chart that does work very well is the DSC Fiddle sticks chart. The problem with a Siemens chart is that the last bit of focus depends on the very smallest part of the chart, so the most critical thing is done with the least optimum setup and the nature of the chart can introduce image artefacts that can fool the camera into thinking its in focus. The cameras focus detection circuits are contrast based so easily confused.

Allister, I have 3 PMW-200's and some days the back focus is good and some days it is way off. I have performed the AFB adjust many times, but within a few days it is out again. Is this a common problem that you have seen with with the 200's?

I have the same problem on occasion...what I do is shift from manual focus to auto focus and then back to manual focus again and it seems to solve the problem for the moment.

Update:

Had a MASSIVE failure last week while in Mexico. Needed to go find a wall mural of black on white to get the routine to work AT ALL... it kept timing out.

Brick wall didn't work.

When it looks good, it's great but this is getting silly...

ADDENDUM:
On the UPSIDE, the back focus is now as accurate as it has ever been...

Just need to carry a spare 10' x 20' WALL MURAL with me everywhere...

I have the same problem on occasion...what I do is shift from manual focus to auto focus and then back to manual focus again and it seems to solve the problem for the moment.

Tried that as well... didn't work for me.

I will be curious to see what becomes of this situation. I plan on purchasing this camera next month. I am a little concerned because I've read about this problem before. And by the way Shaun, I just purchased a pair of Dracst led's, in part, based on your recommendation in a previous thread. They should arrive next week, just in time for a scheduled shoot.

I have shoots for the next two months before I have a chance to send it away so I'm HOPING I can continue to find ways of addressing this issue.

May need to get some HUGE Fiddlehead targets...

Hope you enjoy the Dracasts, Kevin.

Update:

Had a MASSIVE failure last week while in Mexico. Needed to go find a wall mural of black on white to get the routine to work AT ALL... it kept timing out.

Brick wall didn't work.

When it looks good, it's great but this is getting silly...

ADDENDUM:
On the UPSIDE, the back focus is now as accurate as it has ever been...

Just need to carry a spare 10' x 20' WALL MURAL with me everywhere...

Yup, my EX1R had one massive backfocus failure in it's lifetime and it hasn't happened again. It probably is that some machines will experience one failure and then come right back after a full power-down.

Greetings to all...I also have a PMW-200 with F/W v. 1.2 loaded. I thought this corrected the Back Focus issue? I performed the AFB routine after updating the F/W and everything seemed to work fine, but should AFB be performed on a regular basis? Is it something that should be done before each shoot? Like W/B?

I've reviewed several threads from users concerned about PMW-200 Back Focus, but I haven't seen anything from Sony acknowledging the issue, nor have I seen any Sony response with technical feedback? Is this a systemic issue?

Being relatively new to video I don't have a great deal of experience in maintaining video cameras. Is this just something you live with when operating a 'fixed lens' video camera?

Best regards,

J.

Flange Back adjustment should only be done when back focus has "gone out".

In the "Old Days" this was usually when a camera (or more specifically the lens...) was bumped or when temperature changes may have caused different metals to expand and contract, changing the minute distances between mounting points of lens and camera.

The new Sony lenses have a "lookup table" that micro adjusts flange back on the fly, depending on what focal length you are shooting at. This adds a new level of complexity.

If your lens will focus at all focal distances at all focal lengths AND holds focus when zooming out from a telephoto position, you are fine. In fact, you can ONLY make things worse if you try to back focus when everything is working properly...

I've had BOTH kinds of "failures" with the PMW200:
- no focus available to me past 15 - 20 feet at a wide angle lens position
- focus point "wander" as I zoom out after tacking up focus at extreme telephoto (well, as "extreme" as one gets with a 14x wide angle lens, but you get my point...)

Shaun Roemich...thank you for your response.

Regards,

J.

This thread has me seriously reconsidering my intention to purchase the camera. I film a lot of live events where acurate focusing is a must. I spent many months researching this camera and this issuie continues to pop up. I was going to rent one but I would much rather the money go towared the purchase.Is there any one here who is totally satisfied with this camera?

I wish I could help with your decision, Kevin...

What I will say is I'm EXTREMELY happy with the picture quality (especially in 50mbps which I work in EXCLUSIVELY now...) at the price point after adapting one of Alister Chapman's excellent Picture Profiles to accurately reflect the work (and post workflow) I prefer.

Content Browser into FCP HAS it's flaws around file naming (WHY can't I have an incrementing file number counter so I can select a batch of clips, tag them Bob Interview 1 and then have auto increment on the files???) but it's a great, secure workflow.

The LCD screen is AWFUL! Colour is way off (VERY green heavy) and the contrast is excessive to say the least, even after adjusting, Peaking is not sensitive enough and will indicate that stuff in wide angle is in focus when it certainly isn't, the back focus issue is KILLING me (I lost an interview to it being soft when ALL indications were it was in focus)...

Oh yeah and I'd LOVE to see a 2x, 5x, 10x zoom available in Expanded Focus...

The glossy screen makes it exceptionally difficult to use in bright sunshine, even with a sunshade in equatorial sun at high noon.

The EVF is useless EXCEPT for framing.

As well, Sony's cowardly hiding of the DC input jack INSIDE the battery compartment in order to render third party batteries obsolete does nothing more than p*** me off - I HAD hoped to buy a V-Lock adaptor and mounting plate for the camera for LONG shooting times on conferences and use the internally mounted BP-U60 battery to keep it powered while changing batteries like I have done in the past with rented EX3s.

No go.

Gee... THANKS Sony. I WOULD have bought YOUR V-Locks and chargers, BTW...

BUT 4 channels of audio (with two defaulting to the onboard mic for question cueing and/or natural sound) at 24 bit with VERY low noise floor on the preamps for a camera in this market segment, 50mbps, the image quality, real switchgear...

So much to like but it just seems like a BETA release to me...

I'm almost POSITIVE it was marketed as being able to update to support XAVC when I bought it but now I'm hearing rumblings here that it won't be... I'll be EXCEPTIONALLY disappointed if it isn't, ESPECIALLY if I can find the marketing literature I'm positive said it would be...

I won't buy a second one. If I buy another 1/2" Sony XDCamEX offering, it will be a PMW300 with an eye to using a broadcast lens with the adaptor or one of the shoulder cams...

My CURRENT needs are pointing towards an F5 or F55 though so we'll see what direction I go.

Hope this helps...

A Caveat to the above:

I'm NOT a film maker, I'm a working VIDEOGRAPHER... events (conventions, conferences) and live switching, corporate video, promo video... I NEED a zoom lens for almost all of my work. (The F5/55 interest is around my first feature length documentary I'm currently working on).

I have been around long enough to see the absolute value of this camera at the price point. It IS a pro solution in terms of a real codec and post workflow for the serious user.

Frankly, the market this camera owns is UNTOUCHED by any other manufacturer. No one else produces a 3 x 1/2" chip camera shooting 50mbps with a non-AVCHD codec with a zoom lens and 4 channels of audio anywhere near this price point. Oh, and HD-SDI out.

All of which are mandatory for me.

So essentially the camera I would CHOOSE to replace the PMW200 with DOESN'T EXIST.

My critical missing feature that I'm waiting for is 1080p50/60 that ISN'T AVCHD 2.0.

That and Global Shutter CMOS too.

Shaun, in this thread you mentioned the non "AVCHD" codec, what's the benefit in having a camera that does not use this format? In the midst of my reconsideration of this camera, I see that Sony just released the HXR-NX3. This may be a viable substitute. It also has 3 1/2inch sensors and a longer zoom. It has the AVCHD codec and I was wondering what the drawbacks are.

My EX1's and EX3's would often loose focus tracking after travelling in flight cases on airplanes. Bumping the cameras around will throw out the back focus. It doesn't get any worse as the camera ages. It's a annoying but doesn't do any lasting damage.

Shaun, in this thread you mentioned the non "AVCHD" codec, what's the benefit in having a camera that does not use this format?

Much like the early days of editing HDV content, AVCHD is very processor heavy to decode and encode on the fly, being a Long-GOP format, due to it's complexity.

The "ballistics" of editing XDCamEX means better real time performance and less time in transcoding or outputting from an edited timeline in my experience...

Five years from now I'm sure no one will care but I get massively better performance out of XDCamEX right now.

I have had the same focusing problems from day one when I first purchased my EX1.

I love the image quality from the EX series but I absolutely hate how shitty the auto focus performs on the XDCAM's.

I have owned 2 EX1s from back in 2008 when they came out. Both cameras at some point over the years have had to go back for fixing back focus issues. Have to say that I have had no trouble since Sony fixed them and the cameras continue to produce super pictures. I would have thought that the EX1R and presumably the PMWs are based on the EX1 original design and that back focus problems should have been sorted by now.

The servo driven back focusing element is the main reason this is still an issue. The biggest advantage is no breathing when changing focus, but a servo driven lens element needs to be re-aligned when it gets knocked around a bit.

With a 100% manual lens, everything is manual, but you get breathing.