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Old July 14th, 2008, 11:10 PM   #1
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focusing with EX1

I am new to HD format. I use old fashion broadcast camera with B/W viewfinder and ALL manual shooting , including of course focusing. There is a simple method of setting focus accorgingly to distance of subject you film; you just simply zoom in all way to the subject, set focus on it and that's all it will be in focus if you zoom out or fully zoom in. Can this method be used with EX1 lens (can that lens hold backfocus)?
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Old July 14th, 2008, 11:25 PM   #2
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Yes, this method can be used. As well as a couple of methods that may be new to you.

The first is called "peaking". When enabled, the subject in critical focus will have "edges" highlight in your choice of colors (red, blue, yellow, or white). This works by seeing the sharp contrast between edges in things that are in critical focus. It works better for some subjects than others.

The other method is the "expanded focus" button on the handgrip. If you frame up your subject, then press this button, it "zooms in" for you allowing you to critically focus and then you press it again to go back to your normal framing. If you don't press it again, it goes off in 10 seconds or so.

When I first tried shooting with the camera, I didn't know much about how these features performed, but to be honest, they are AMAZING. There is also a DOF available on the LCD to let you see where the lens is focused, and what your DOF is in the shot. Truly amazing stuff for a camera at this price level.
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Old July 14th, 2008, 11:45 PM   #3
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thanks; so it looks like there is no need for extra lcd monitor; camera's lcd should handle it OK? right
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Old July 15th, 2008, 12:17 AM   #4
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Originally Posted by Marius Boruch View Post
thanks; so it looks like there is no need for extra lcd monitor; camera's lcd should handle it OK? right
Depends on what you're doing. If you're out in the field handheld, on a stabilizer, or need to be mobile, I'd say no.

However if I was going to be shooting a film, or something where not only the principle was important, but the rendering of details around the principle, as well as the falloff of focus around the principle, I'd still want as large a monitor as I could get.

I plan on using the component out to drive my broadcast monitor on my upcoming work. I've got an interview this week with someone for a documentary that I've been working on for a while, and I am SURELY going to take the monitor with me even though it's a pain.

But I have more confidence in focusing the EX1 than any other camera I've ever used, including my DVX which has a *GREAT* LCD.
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Old July 15th, 2008, 05:26 AM   #5
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I use only the eyepiece viewfinder and depend a great deal on the expanded focus feature. Almost all of my shooting is run-and-gun style due to the nature of the subject.

The LCD is too difficult to see in daylight and it's impossible to judge exposure as I rely on zebras, the histogram and watching out for burned highlights in skin tones.
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Old July 15th, 2008, 08:40 AM   #6
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Quote:
Originally Posted by Marius Boruch View Post

There is a simple method of setting focus accorgingly to distance of subject you film; you just simply zoom in all way to the subject, set focus on it and that's all it will be in focus if you zoom out or fully zoom in. Can this method be used with EX1 lens (can that lens hold backfocus)?
Not in my experience you can't. The focus performance in my judgment is not anything to rave about.

Rather than zoom in, focus and zoom out,
try the opposite. Start at a wide angle zoom, get focused on the target with the peaking and expanded focus aids, then zoom in on the target. It will be much easier to see if it maintained focus, which in my case it does not.
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Old July 15th, 2008, 09:49 AM   #7
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so it looks like there is a problem with the lens
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Old July 15th, 2008, 10:33 AM   #8
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Originally Posted by Tom Roper View Post
to see if it maintained focus, which in my case it does not.
If you cannot rack focus you most likely have a problem with backfocus and should do the FB (Flange Back) adjustment from the service menu (or have it done, since it is not officially supported for end-users).

Racking focus by zooming in and then out to frame the scene should be ok.

George/
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Old July 15th, 2008, 10:49 AM   #9
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so it looks like there is a problem with the lens
I'd really like for someone to get focused at wide angle zoom, and hold that focus when zooming to telephoto.

And will it work in full manual mode as well as servo manual?

In full manual, my lens will focus past infinity. In servo manual, it will not.

The camera has some incredible abilities, the lens system you have to be careful with getting your focus. The zoom in, focus and then zoom back out has caused me some soft focus problems. I don't trust it nor the service menu back flange adjustment procedure to make this right.

For critical focus, I've had to focus at the zoom angle I'm using for the shot meaning heavy reliance on peaking and expanded focus functions.

If I'm going to zoom, and require critical focus at each end of the zoom, I will use the shot transition, whereby the focus and zoom is set at each end.

I wish it was easier. It's not impossible to get focus tack sharp, but it takes some effort. And the peaking is not nearly as effective with detail (sharpening) turned off. So if you don't want sharpening in your image, you have to create one preset just for focusing with detail on, and then switch to another with detail off for the shot.
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Old July 15th, 2008, 11:44 AM   #10
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Originally Posted by Tom Roper View Post
In full manual, my lens will focus past infinity. In servo manual, it will not.
It is normal for a pro lens to go past infinity.

Quote:
Originally Posted by Tom Roper View Post
The camera has some incredible abilities, the lens system you have to be careful with getting your focus. The zoom in, focus and then zoom back out has caused me some soft focus problems. I don't trust it nor the service menu back flange adjustment procedure to make this right.
In these modern lenses the camera continuously 'talks' to the lens to compensate for technical imperfections, even in full manual. In interchangable models Lens Files are used to load correction parameters either from a file or directly from memory contained in the lens. In the EX1 this file is contained in the camera.

It has a Lookup Table (LUT) with the adjustments necessary for consistent backfocus. By performing the FB Adjust function focus for wide and tele positions of the lens are checked and the table rewritten for consistent focus throughout it's zoom range.

The FB Adj. function is present for the Z7/Z270 and EX3 interchangeable lens camera's, but "hidden" in te service menu for the EX1. I believe this is mistake by Sony even though the EX1's lens is fixed, as environmental changes can affect backfocus.

Adjusting backfocus is Standard Operating Procedure for professional camera's and is recommended with any lens or location change.

Quote:
Originally Posted by Tom Roper View Post
For critical focus, I've had to focus at the zoom angle I'm using for the shot meaning heavy reliance on peaking and expanded focus functions.

If I'm going to zoom, and require critical focus at each end of the zoom, I will use the shot transition, whereby the focus and zoom is set at each end.
You shouldn't have to take such elaborate measures, just to get the focus right. Barring any lens defect, correct backfocus should take care of your issues.

George/
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Old July 15th, 2008, 11:56 AM   #11
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George, I appreciate the time you take to understand.

Can you get focused at the wide end, and maintain that focus when racking to the telephoto end?

(Yes, I know this is backwards and tedious, but if it can't, then racking from telephoto to wide will not be perfect either.)
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Old July 15th, 2008, 12:17 PM   #12
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Long answer short: Yes I can.

B.T.W. it is easy/easier to misjudge focus on a wide shot, so usually you focus on the long end of the lens. There is no advantage to going the other way that I'm aware of.

George/
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Old July 15th, 2008, 12:58 PM   #13
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Originally Posted by Tom Roper View Post
Can you get focused at the wide end, and maintain that focus when racking to the telephoto end?
Tom I understand your concern. I spent several times adjusting BF before it set correctly.

I'm not sure about starting wide than checking focus on the tele end.
It's to subjective to where you leave focus at the wide end. A hardly noticeable difference of focus on the wide end yields a large change on the tele end.

I see that George just wrote what I stated above..
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Old July 15th, 2008, 01:09 PM   #14
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I zoom in full tele then hit expanded focus adjust focus then zoom back to frame and have great results, Now trying to adjust focus at wide when you are going to end up at Tele the focus set at wide will not hold at tele and you will have a soft image...Now if I had a Back focus issue the way I focus above would be soft once I zoomed back out correct?
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Old July 15th, 2008, 01:29 PM   #15
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Back focus is set by zooming in and focusing on your target.
When you go wide your target should still be in focus.
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