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Old April 7th, 2008, 04:12 PM   #1
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At full tele and near infinity focus issue..

The other day we brought the EX1 and the RED ONE out for some testing.

An odd thing happened with my EX1 that I have never seen with this camera.

At full zoom I focused at near infinity (over 150 ft.). ODDLY, the right side of the screen was out of focus and had really bad CA. I'd say it was at least 1/3 of the frame on the right side.

I noticed this same problem with other similar far focus zoom shots taked that day. The next day I tried recreating this issue. Before testing. I pulled the camera out of manual focus, and then back. (maybe it somehow shifted?). I need to test more, but it did not seem that bad, although it did appear a tad soft at full zoom and near infinity focus. I will post this shot.... It's odd, believe me...

I need to test more.
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Old April 7th, 2008, 04:51 PM   #2
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same problem with my EX1

My EX1 shows the same effect. Had it at prime support for 4 weeks now to fix the problem and got it back today with things almost unchanged: When I turn the zoom to max. tele, I can either focus on the left or the right side of the object. I am getting annoyed about this ...

Besides the issue with the disappearing paint on the backplate was fixed. But now if see, that alomst all paint at the ND-filter button and the costum-keys can be rubbed off.

Don't want to wait another couple of weeks and will discuss with prime support the opportunities to get a well-oiled cam with visible inscriptions.

Rgds, Eva
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Old April 7th, 2008, 06:06 PM   #3
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Eva,
I only saw the focus issue I described at full zoom while focusing at near infinity.


I need to test more to be sure.

Do you have this problem when focusing on shorter distances less than 10 meters?

I performed more tests with info listed below.
http://dvinfo.net/conf/showpost.php?...15&postcount=8
I will post images tonight.

Last edited by Steven Thomas; April 8th, 2008 at 04:45 PM. Reason: new info
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Old April 7th, 2008, 06:38 PM   #4
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Quote:
Originally Posted by Steven Thomas View Post

Do you have this problem when focusing on shorter distances less than 10 meters?
YES, I do. Looks like the optical axis between lens and chips is improperly adjusted. To test it, I use a plain fine structure (e.g. the rough plastery in my living room) and can show how the focus moves from right to left and vice versa. I found out about this when doing some landscape shooting, where the trees on the left hand side did not look as sharp as on the right hand side. If will follow up with prime support to get rid of this and will report later.

Last edited by Eva Sturm; April 7th, 2008 at 07:20 PM.
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Old April 7th, 2008, 06:55 PM   #5
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Thanks Eva.
Let us know how things work out for you.

How far away was your wall, less than 4 meters?

It sounds like what I saw, but in my case the right side was out of focus.
Also, mine was only showing the issue at far focus. I'm not sure at what focus distance that this issue starts to appear.

I do know that my close full zoom tele shots looked fine.

I'm going to do some more tests.
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Old April 7th, 2008, 07:18 PM   #6
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Thanks Eva.

How far away was your wall, less than 4 meters?
Mmhh, even less. I've prepared a small pdf-doc with some pics, but failed to upload it onto my website cause I've exceeded max. allowed storage. Have to delete some stuff and try again. Will do this tommorrow, need to hit the sack now, uhhh...
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Old April 7th, 2008, 11:04 PM   #7
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Given all the issues from vignetting to back focus and now this I am beginning to think the lens on this camera isn't the best thing about the camera. What F Stop does the distance focus issue occur? I had a Canon 18x professional lens which had a similar problem and the cost to repair it was prohibitive.
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Old April 8th, 2008, 07:40 AM   #8
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Well, after more testing, it appears my camera does have an issue.
The left to right focal point changes a lot sooner than I thought!

I ran tests at full tele zoom and focusing at several distances.
Even focusing at 30 feet, the problem was easily seen.
The right side is out of focus and displays horrible CA.

At shorter focus distances there's less problem.

I'm really puzzled here. This is my second camera. The first one had the vignetting problem.

Any thoughts on what may be causing this?
I'm going to contact Sony support today.
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Old April 8th, 2008, 08:05 AM   #9
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Steven,

That's a weird one. If there were a flange/backfocus irregularity (chip misalignment etc.) you would expect it to be most evident at the widest zoom settings, not full telephoto, where depth of backfocus is the greatest.

So I am leaning toward an internal lens problem of some sort.
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Old April 8th, 2008, 09:08 AM   #10
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I agree.

I'm a bit puzzled about the whole thing...
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Old April 8th, 2008, 10:27 AM   #11
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when we have a new probelm with the camera, would it be best
to mention serial number and FW.
Regards brian
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Old April 8th, 2008, 11:29 AM   #12
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I'm sure most cameras are fine, but I suggest everyone grab their cameras and verify they do not have this issue.


Zoom all the way in and focus on objects on the same plane at greater than 60 feet away.

Look at the image on your monitor and make sure their is not a shift in focus across the image plane.

I will be attaching examples to my post tonight. It's not pretty!
Even focusing 30 feet at full tele there's a gross focus deviation across the image plane.
Also the out of focus side has bad CA.
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Old April 8th, 2008, 11:42 AM   #13
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What you would expect at full tele is that the DOF is the shallowest. If you are not at a right angle to the object (a wall maybe), could you be seeing the focus change because of the DOF?

For a 35mm lens at comparable focal length (440mm) DOF is only 3.5 ft at F2.0 at 150 ft. I'm not sure how this is for the EX1; it could be 20x as long.

However to exclude this, focus on something small/contrasty at the left side of the LCD and then pan so it's on the right. It should still be in focus.

If it changes, there could be some alignement issue or maybe even an issue with the lens internals.

George/
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Old April 8th, 2008, 12:29 PM   #14
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Quote:
Originally Posted by George Kroonder View Post
What you would expect at full tele is that the DOF is the shallowest. If you are not at a right angle to the object (a wall maybe), could you be seeing the focus change because of the DOF?

/
No sir!

All focused objects were on the same plane.

In fact, one test I will be posting tonight is my wife and step son leaning against a wall 60 feet from the EX1. The EX1 was aiming directly straight at the subjects (no angle). The wall was not on an angle to the camera..
Yes, I intentionally kept the apeture at wide open and used ND filters and shutter speed to obtain a reasonable exposure.

I realize the DOF will be tighter, but there should not be this much focus deviation. There's clearly an issue here.

On top of that, one shot I have focus near infinity (full tele zoom), the defocused area has EXTREMELY bad CA. It's not pretty. that's for sure.

I think you're right about the lens or internals. There's something shifted for sure.
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Old April 8th, 2008, 12:40 PM   #15
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repeat post...
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