Z7 MAJOR problem?

[Bruce Ostrout]

Originally Posted by Keith Forman

Yes, it was a very dark room and the f-stop was fully open. no gain. it looks like a narrow depth of field issue but not a camera problem.

When you zoom in your depth of field is most narrow as you zoom out the DOF gets bigger and your subjects that you marked in your focus technique do not get blurrier. You cannot see this on your cam LCD you have to put it on a regular HD display.

[Keith Forman]

Originally Posted by Bruce Ostrout

Dude you have to watch the video. I don't know what you did to that second grab. Looks like you put a gaussian on it to even out the blur. The first grab is from where I zoomed in to pull focus and then you see I zoom out and the subject I placed in focus goes blurry but everything from the center to the right of it at the same focal length is in focus. Sony just called me from NAB and said they are analyzing everything now. So if you have a Z7 don't want to be stuck with a major issue of a half muddied up frame for a large portion of your shots you need to do this test properly.

I didn't do anything to the grab. The fact that the blur switches sides from your grab to mine makes me think that it is either depth of field issue or because it was not taken from static shooting. Did you have auto focus on?

[Bruce Ostrout]

Originally Posted by Keith Forman

I didn't do anything to the grab. The fact that the blur switches sides from your grab to mine makes me think that it is either depth of field issue or because it was not taken from static shooting. Did you have auto focus on?

Full manual on everything, not even servo zoom. I never use auto focus on my cameras at any time.

This is the screen grab from the same video, not deinterlaced. http://www.firstsightpictures.com/Image0.jpg The right side is a little soft, which it shouldn't be, but the left side is considerably more blurry. This particular one was right after a manual flange adjustment, which could be slightly off, but with all adjustments the one constant is an uneven blur at 1.8-2.0 at 60-90% telephoto. Here is a screen grab from the first cam Marshall Levy tested http://www.therealmav.com/bruce01.jpg

he had the PAR wrong and the curved table makes it more exaggerated, but you can still see the same issue, just flipped. Clear on one side very blurry on the right.

You can see the dance footage I posted. Dancers in focus on zoom in, zoom out 10%, dancers a little soft. they move left and they get very blurry. The whole time they never changed their front to back distance to the camera only moved side to side.

[Bruce G. Cleveland]

Originally Posted by Keith Forman

I have to reevaluate. After reviewing the footage I took yesterday it appears to be not as much of an issue as I first though. It may just be an extremely narrow depth of field and not a camera issue with mine.

This is exactly what I have been thinking. Very narrow depth of field. I have always noticed this to a degree with our 170s as well, but when you go to HD everything is going to be magnified. When a camera is zoomed all the way in you do not have much you can focus on and anything slightly different in distance is going to be out of focus.

Bruce Cleveland

[Bruce Ostrout]

Originally Posted by Bruce G. Cleveland

This is exactly what I have been thinking. Very narrow depth of field. I have always noticed this to a degree with our 170s as well, but when you go to HD everything is going to be magnified. When a camera is zoomed all the way in you do not have much you can focus on and anything slightly different in distance is going to be out of focus.

Bruce Cleveland

I am quite familiar with shallow depth of field. This has nothing to do with that it has to do with lens inconsistency at certain focal lenght and aperture settings. What you have focal length targeted in frame is NOT supposed to go out of focus when zooming out and as you zoom out the DOF gets wider so MORE things will be in focus not LESS and most certainly not your subject that hasn't moved. The tree on the right stays in focus as the focus target goes out of focus which is at the exact smae distance from the house as the other tree. Here is another clip i just took after a auto flange adjustment and better exposure that shows the right tree sharp and the left side burred as it has on every camera so far.

http://www.firstsightpictures.com/z7blur3.wmv

[Steve Gerhart]

I have asked this question a couple of times, maybe Juan Martinez can answer, he seems to know alot about this camera as his presentation was quite knowledgeable

One thing I don't quite understand is this from Sony that states "To address back-focus concerns, the Zeiss 14X and 8X zooms maintain automatic back-focus adjustment (akin to the automated back-focus routine in the EX1's service menu)".

[Bruce G. Cleveland]

Bruce are you saying you have it in manual or auto focus? I thought you said manual focus.

Bruce

[Bruce G. Cleveland]

Never mind my last question. So the camera on manual focus should not be trying to focus on anything. And you are saying that on manual focus when you pull out it is going out of focus on the sides? Sorry if I seem dense on this problem. I am trying to replicate and not sure what I am supposed to be looking for.

Bruce

[Zach Love]

wow... this does look really bad. I'm thinking of the EX1 a little more now.

but onto trying to figure this out, I looked at a Z7 a couple weeks ago, the store had only one in stock & had to take it out of the box to look at it.

I remember seeing a focusing chart in there, can you shoot some more video of the camera pointed at the chart?

zoom in, set focus, zoom out. pause. pan left. pause. pan right.

if someone can do this I'm guessing it will show the problem clearly & rule out any DOF issues

[Bruce Ostrout]

Great idea Zach! It is raining outside but I took an umbrella out and did a test againast my garage door and it does indeed show it getting soft when you start to zoom out and then the left softer than the right. I am going to get the other focus chart out of the box in storage and shoot two charts one on each side and I'll post it in an hour or so.

[Bruce Ostrout]

Originally Posted by Zach Love

wow... this does look really bad. I'm thinking of the EX1 a little more now.

but onto trying to figure this out, I looked at a Z7 a couple weeks ago, the store had only one in stock & had to take it out of the box to look at it.

I remember seeing a focusing chart in there, can you shoot some more video of the camera pointed at the chart?

zoom in, set focus, zoom out. pause. pan left. pause. pan right.

if someone can do this I'm guessing it will show the problem clearly & rule out any DOF issues

Here is a screen grab. 20 meters away centered exactly on the middle square. Pulled focus on the left target and zoomed out about 20% F1.8 http://www.firstsightpictures.com/Z7focuschart.jpg

[Keith Forman]

Originally Posted by Bruce Ostrout

Here is a screen grab. 20 meters away centered exactly on the middle square. Pulled focus on the left target and zoomed out about 20% F1.8 http://www.firstsightpictures.com/Z7focuschart.jpg

no doubt that there is some blur but the camera does appear to be slightly off center--closer to the left side...

kdbf

[Bruce Ostrout]

Originally Posted by Keith Forman

but the camera does appear to be slightly off center--closer to the left side...

kdbf

#1 the camera was exactly centered. Measure the squares..... #2 It wouldn't matter anyway because my focus target was the LEFT target so if anything should be out of focus it would be the RIGHT target, but no the right target is in the focus plane and the left goes out of focus.... Here is the actual footage showing that. It is drizzling so i am holding an umbrella so it is a little rough the jump back is the digital extender so i could pull tight focus. Then it jumps to the pan, but no settings were changed i just consolidated the footage for smaller file size. http://www.firstsightpictures.com/z7blur4.wmv

[Bruce Ostrout]

Here is the grab of the same thing from another Z7 the serials on the two that I have here are 110022 & 11002

http://www.firstsightpictures.com/Z7focuschart2.jpg

[Filip Kovcin]

Bruce,

can you kindly check two things - if possible:

1. since you have TWO cameras, please - switch the lenses from one to another and chech how it looks. if you record same settings, composition, light and camera position with TWO different lenses - if the problem is within lenses - still grabs will be different, if equal - this means that problem is inside the camera.

2. i am not sure with this, i do not have the camera and lens myself - didn't check that - can you check is it possible to detach lens from the camera and turn it 120 degr. and mount it again in new position.

OR

at least - detach the lens and put it back as close as you can - but DO NOT mount it! try to find proper sharpnes - some vignetin will occur, i know, but at least you can TURN lens clocwise to see where - if any - blurring is positioned now.

that way you can check is this blurring connected with lenses or with something else inside camera - personally i beleive that problem is within lens.

thank you,

filip kovcin