The method I described at the beginning of this thread is an accurate way to test back focus as are all of Gerald's comments. Like Gerald I spent many years as a 16mm tech and worked in rental houses checking lens back focus more times than i would like to recall. its not brain surgery and its easy to tell if you are on or off, but a large monitor is essential.

Lenny Levy

The method I described at the beginning of this thread is an accurate way to test back focus as are all of Gerald's comments. Like Gerald I spent many years as a 16mm tech and worked in rental houses checking lens back focus more times than i would like to recall. its not brain surgery and its easy to tell if you are on or off, but a large monitor is essential.

Lenny Levy


I feel like my bf is not as sharp as I would want it but i'm pretty much done with this subject for the next 3 months. I'm not going to even worry about this for a couple of reasons.

A. there is nothing you can do to completly make it perfect that has been confirmed.

B. i'm going to wait till sony makes a press release or has some documentation about the situation and an updated firmware that specifically fixes the bf problem.

Until then, i'm going to do like Phil Bloom and focus on the things that the camera CAN do.

I feel like my bf is not as sharp as I would want it but i'm pretty much done with this subject for the next 3 months. I'm not going to even worry about this for a couple of reasons.

A. there is nothing you can do to completly make it perfect that has been confirmed.

B. i'm going to wait till sony makes a press release or has some documentation about the situation and an updated firmware that specifically fixes the bf problem.

Until then, i'm going to do like Phil Bloom and focus on the things that the camera CAN do.

I'm not sure how you define perfect, but it's not an issue with some cameras. Gerald was able to adjust two cameras. Mine never had the problem, and I'm as anal as they come... LOL...
Now, don't get me going about vignetting. That's another story.

You're right about kicking back and waiting for Sony to address this issue with an official statement. It's obvious they know this is an issue. There have been some that have tried a couple cameras just to find out that they all had the BF issue.

Gerald.

As usual, I probably opened my mouth a bit too soon.

I also endorse Gerald's comment. Enjoy the things the camera can do. I regret I did not have any more than my few hours to play with the demo camera here.

It did not seem to have a backfocus problem and the dealer suggested that the vignette problem had been dealt with when I mentioned it.

I did not find it in direct-to-camera use but with a Mini35 on front, the steadyshot had to be turned off otherwise it did bring in the edges of the prism path very deep into the TV safe area.

Got my camera back from Sony. They where pretty fast from the free pickup to return it took only 5 days (weekend inbetween).
They updated the firmware to 1.05
Focus with N2 perfect.
Focus with Nd1 and Nd off slightly soft.

After doing the fd autoallign to a brickwall at about 13m away,
it keeps focus in all nd settings.

That prooves in my opinion
firmware 1.02 no go , firmware 1.05 works (can´t say anything about 1.03)
and sony has problems using their own autoallignment, but they obviously try to do their best with a fast service.
So after messing around for nearly 2 weeks with that problem, I seem to have a fixed cam now.

Thats like most electronic products nowadays:
They are like bananas, they ripen at the client.

Holger

Good to hear that you have a sharp cam now, Holger, after laying hands on yourself.
Anyway, returning it to you with focus slightly off for the two main ND settings is not what I would expect from a Prime support. Don't forget that Europeans pay a premium of about EUR 1,500.00 for this service.

Well I didn´t pay extra for premium support.
I bought my camera in late december at videocation in munich an got 2 years of premium support included.

Holger

What I am referring to is that the much higher European price is a result of the included Prime support.

I like the 13m and brick wall to adjust BF it makes sense to me.

Got That prooves in my opinion
firmware 1.02 no go , firmware 1.05 works (can´t say anything about 1.03)
and sony has problems using their own autoallignment

Well, I've just checked mine FW - it's 1.02_0337, and I never had problems with back focus (which of course doesn't prove anything), but:

- have you noticed any other change in your camera performance, which would be worth sending mine for the FW update?

Well up to now, I couldn´t find any obvious changes.
As Sony likes to keep things secret, there is no kind of documentation about what has changed. They don´t even send back a remark what has been done with the camera.
And, to be honest, I think they don´t document it cause its just bugfixing.
Normally if they got a new feature or real improvements, they don´t keep that quiet.
But I really would like to know how many undiscovered bugs are sleeping, just waiting to give us the next hard time.

Holger

But I really would like to know how many undiscovered bugs are sleeping, just waiting to give us the next hard time.

The EX is a Cylon camera, with all the memories and experiences of a normal human made Sony device........until activation. Then it will........rebel. Dramatically.

How could you humans have all been so blind?

Dr. Baltar
Instrument of God.

I am sending my cam in to Sony today to have them fix the backfocus (and zoom toggle). Wish me luck.

I picked up my loaner from the dealer. The BF is certainly better on this. I need to test a little more to see if its spot on.

I just tried another EX-1 that my old company just bought. Their backfocus was off too as it turns out.

Sheesh.

B

I sent my ex1 back for the backfocus issue and happen to read the posts about the telephoto issues related to focus.. I Sony to make sure they also checked the lens for that as well. The tech said it was already packed and will likely ship out today... I told not ship it back unless they were sure the lens was ok, he claimed they had already addressed that issue while it was there.


I guess I will find that out in a few days

Chuck

Let us know how it works out Chuck.

I wonder how they check far focus using full telephoto.
They mentioned they checked for this?

They would have to have distant objects greater than 60 feet from the EX1 with the objects set in a line at the same focus distance and have them cover the entire field of view. Of course, the camera should not be angled to the subject and ideally set to f1.9 (open) to have DOF as tight as possible for critical adjustment.

Which brings up the million dollar question, what is the adjustment for this issue?

Press and hold the cancel button and menu button at the same time. Continue to hold these buttons and then hit the SEL/SET button. 3 more menus will show up below the regular menu items. Scroll down to the IF icon. Select that and you'll see your serial number and the firmware version number appear.

- Don

Hi, I just wonder how do you get rid of that extra menu?

Thank you

The menu disappears when you turn off/turn on the camera.

... or CANCEL back, and press the MENU button as ususal ;)

Eric's right, once you enable the service menu it remains until you power off.

A quick question regarding focusing on infinity. Is it normal to have to roll back a bit from the full-stop setting of my focus ring to get to the infinity setting?

If I go to the full-stop on my focus ring, it seems to be focusing PAST infinity and I get a blurry image. Is this indicative of a back focus problem?

Zachary,

All pro lenses go past infinity by a bit.

The infinity mark should be infinity, not the lens stop position.

This is not indicative of the backfocus problem.

If you have to roll your focus to significantly less than infinity at wide angles to improve the focus of distant objects, then that's the backfocus problem.

For example, some have said that their best wide angle focus for distant objects appears when the lens is focused at 3 feet.

On my camera, despite several careful backfocus adjustments, I have to bring my focus to the 15' mark or a bit less for the best focus of distant objects when fully wide. I would call mine a mild backfocus problem.

Thanks Eric - I thought as much, but I was surprised that my infinity focus is best a few mm on the close focus side of the dial of the actual infinity mark. I'm testing the BF outside, and am having difficulty discerning if I have the problem or not. I'm guessing that's because I don't - even though my firmware is v1.02. Worth sending it into Sony for an upgrade if I have a few weeks before my next shoot?

Yours sounds like it's the same as mine. I will send mine in eventually, but in the mean time, I just cheat the focus closer when I'm doing wide shots.

I'm waiting until July or so when the new firmware comes out for the EX1 - it is rumored that we will be able to install it ourselves. I also have 1.02 but unlike many with the classic backfocus problem, my focusing is the same with all ND settings.

I just cheat the focus closer when I'm doing wide shots.

Just had a little 'ah-ha' moment...

There's a thing called the 'hyperfocal distance', which means, given the apature of a lens at a given focal length, is the optimal focus setting to get acceptable focus from infinity to something close up.

So if you take a PD150 zoomed out to the widest it will go, dial in F4, set focus to about 2 meters, infinity to about a meter and a half is going to be in focus. According to Christina Fox @ Urban Fox (purveyors of fine training to the BBC):

http://www.urbanfox.tv/workbooks/sonyz1/z1focus.htm

The Z1 is better - set at 1 meter, but she doesn't mention the F4 bit.

Anyway... IIRC, an attempt at hyperfocal distance didn't work for me before I did the 12-chart test. And even then I fluffed it because I didn't take into consideration the 1/2" chips effect.

Does the FB issue put infinity just outside of reach of the end stop, or a little bit before it? I felt that it was always a bit beyond the end stop which is why I never could get it.

Still, distant objects should be sharper (or just as sharp) at infinity than at hyperfocal.

My experience on the EX1 is that the world gets softer at infinity than it is at a closer setting - so I use the closer setting.

Most other posts that I have read say that focus for distant objects gets sharper at closer settings, so it ca be said that infinity in before the end stop, not past it.

My camera shipped with the 1.05 firmware and has the non-parfocal behavior. It does not have the problem of different backfocus for different ND settings.

I don't understand how firmware is expected to solve the non-parfocal behavior in a mechanical lens design. This makes me skeptical. The exception would be if one of the focal elements is servo controlled even while in full manual.

If firmware was used to compensate for a fundamentally non-parfocal mechanical lens by adjusting the position of a servo controlled backfocus element within the group, it would be because the mechanically linked focus element is out of position.

I'm hesitant to perform the back flange procedure. My camera is pin sharp.

Although it would be extremely convenient to zoom in on the subject, focus and zoom out, Sony has provided effective tools for acquiring focus at wide angles, vis-a-vis the peaking controls which are the best I've seen.

The peaking has 3 color choices, but more importantly by choosing low, mid or high you can choose how much peaking to overlay the scene.

I found that by setting the iris to f1.9 and turning on the peaking, I can manually focus distant, featureless landscapes at wide angles, and observe the broader effect on the overall frame, near objects as well, by painting the image with yellow peaking. It's more trouble, but it's more effective for accurately getting all the desired subjects within the frame in focus than arbitrarily choosing one object in a parfocal method (even if it worked, which I'm not convinced it will.)

The expanded focus also works well, for getting a subject's face in focus from a wide angle, without first zooming in manually.

The improvement Sony could give us in a firmware update, would be to enable peaking and expanded focus at the same time.

I know there are strong opinions counter to this. I'm just giving you mine. I don't completely trust zooming in for focus, and then zooming back out even on lenses that are known to be parfocal, which in the case of EX1 Fujinon, there's reason for some doubt.

I don't understand how firmware is expected to solve the non-parfocal behavior in a mechanical lens design. This makes me skeptical. The exception would be if one of the focal elements is servo controlled even while in full manual.


And indeed it is, Tom - the EX1's lens is never fully "mechanical", AFAIK.

Also, Wikipedia says (http://en.wikipedia.org/wiki/Parfocal_lens):

"Many so-called "zoom" lenses, particularly in the case of fixed lens cameras, are actually varifocal lenses, which gives lens designers more flexibility in optical design trade-offs (focal length range, maximum aperture, size, weight, cost) than parfocal zoom, and which is practical because of auto-focus, and because the camera processor can automatically adjust the lens to keep it in focus while changing focal length ("zooming") making operation essentially the same as a parfocal zoom"

I have bolded out the fragment, which confirms it can be done by the electronics (with a little help of some servo, of course).

But if you say your camera is pin sharp, I wouldn't adjust anything, either. And you're absolutely right that while the expanded focus feature is great, it would be even more useful with peaking on!

Just had a little 'ah-ha' moment...

There's a thing called the 'hyperfocal distance', which means, given the apature of a lens at a given focal length, is the optimal focus setting to get acceptable focus from infinity to something close up.


Purely for the record: the hyperfocal distance represents a special case of depth of field in which objects at infinity, as well as near, are of acceptable sharpness. If the lens is focused at the hyperfocal distance, all image points between one-half that distance and infinity will not exceed a specific diameter of circle of confusion (i.e. acceptably sharp). That's how a fixed lens (non-focusing) camera is set up.
That distance (H) is determined by focal length squared divided by the product of f/stop and dia of circle of confusion. So the higher the f/stop, the shorter is H. As you know, H is a variable in DOF calculations.

One thing for sure...

I'm finding the auto back focus feature on the EX1 to be very sensitive. I have the latest software 1.05 and regardless of ND on or OFF it can be a pain to get it set correctly. Also, I've seen nothing on my camera that shows I need to run the back focus on all ND filter conditions.

I've heard some say you can set it up at 3 meters away, and others mention more than 4 meters.

On mine, it seems to work best if you're over 4-5 meters away.
Also, the target must be larger and of course on the same plane with nothing else in the field of view when wide.


Honestly, I really WISH Sony would offer the FB (Flange Back) back focus adjustment with manual assistance control. This would allow accurate back focus settings.
This would be one featue I'd like to see implemented in the upcoming software release.

Hello :)

This is my first post as a EX1 owner and after reading the entire thread, one of the first thing to do was to set the back focus with the described procedure.
Of course I checked it before and it was definetly off.

So: setup Siemans Star on the wall, clearded the obstacles in the room and EXECUTE.

Only one time executed and it's perfectly in focus now over the entire range. Nice :)

Before and after this, there was and is no difference between no, 1st and 2nd ND.
Which make sense to me as it's mechanically brought into the way as one can clearly hear by swithing it to the different positions.

Thanks!

I guess I have several posts here in the near future, now exploring all the functions of this beautiful camera :)

Peter

So do the numbers on the focus scale match the distance to a far away target when the zoom is wide?

I've same issue, on my ex1 after focused on a obect and pull back the zoom everything is blurred. only with ND1 and ND2.
can I do the fix procedure only for ND? without ND focus is perfect...
I saw the video on Vimeo by Paul Kellett and I realized that the fix is very simple, but what are the conditions? (Distance, light)

Firmware 1.11

Edit:
EX1 back focus demo on Vimeo
Procedure ok and ex1 works fine
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On my ex1 the backfocus can never be achieved perfectly.

When zoomed out, I will always get a sharper image when I turn the focus ring to Infinite distance. Especially on objects closer to the lens, I can see the sharpness gain when focusing far.

The problem only occurs when zoomed compleetelly out. Just a little zoon in, makes the image much sharper, and at the correct distance focus.

The auto BF dosent fix the problem, alltho it seems to do it... Right after the OK confirmation, the image is as sharp as it can be.. Then after 5 seconds when the focus wheel reclaims control, the image goes slight out of focus. When "MF assist" is enabled, I get reconfirmed that something is wrong.

I focus on an object 3 feet away. Zoom out, enable MF assist, and the focus turns all way to infinite. Image becomes sharper.

The things I mention here are subtle, and you can probalby only see the defocus on a good and large monitor, while focusing on the starchart.

However ever since I bought the camera (used) I had the feeling that the zoomed out image was softer than it's used to be on the rental ex1's I used before.