Backfocus problem? at DVinfo.net

Erik Palm · February 28th, 2007, 11:07 AM

I work as a videojournalist and have a A1 PAL version. I had problems with blurry faces shooting 4:3 SD just like Jan Luethje. Haven´t looked at HDV on a monitor yet.
http://www.dvinfo.net/conf/showthread.php?t=87214
My professional collegues, that shoot 2/3' P2 cameras thinks the camera has a backfocus problem, similar to the one of Sony PD150, after testing it.

Has anybody else noticed backfocus problems?

(Test it by for instance focusing manually close up on somebodys eyes, zoom ut while leaving the focus unchanged. For me, the focus ended up on the ears or shoulder after zooming out instead of the eyes. The picture was blurry too)

Thanks Erik

Bill Pryor · February 28th, 2007, 02:10 PM

Back focus was the first thing I checked out, and mine is fine. It could be you have one with a problem. I would go back to where you bought it asap.

John Brinks · March 3rd, 2007, 12:12 PM

I thought the a1, had the type of lens that needs to be refocused after zooming?

Bill Pryor · March 3rd, 2007, 12:15 PM

No. You use it like any other lens--zoom in and get critical focus, then zoom back to where you want to be for the shot. If it doesn't stay sharp, there's a problem.

John Brinks · March 3rd, 2007, 01:44 PM

Mine definitely needs to be refocused after zooming... if i go from a wide shot to a closeup, the focus changes completely.

Khoi Pham · March 3rd, 2007, 01:48 PM

Quote:

Originally Posted by John Brinks

Mine definitely needs to be refocused after zooming... if i go from a wide shot to a closeup, the focus changes completely.

It is the other way around, zoom in first and then pull out, it should be in focus, if not then back focus is off, if you focus at wide and then zoom in, all camera will be out of focus.

Erik Palm · March 10th, 2007, 04:32 AM

I let you know what Canon says. /Erik

Lynn King · March 29th, 2007, 08:17 AM

I had the same back focus problem with my G1 and returned it. I've had no problems with the new G1. You should send your camera back immediately.

Erik Palm · March 29th, 2007, 01:20 PM

Canon adjusted the focus, now it seems better. Only tested a few minutes the other day. But I'm not that impressed by the DV quality. Tricky too make it look good. I think I shoot HDV and downconvert only - takes some time to process though.

/Erik

Eric Weiss · March 29th, 2007, 01:32 PM

can you upload a sample of said DV?

Randy Panado · November 22nd, 2007, 12:26 PM

Mines displaying a back focus problem as well. I'm going to take it into Canon to see what they say about it. I guess for now I'll have to live with manual focus for this next gig I have coming up.

Bill Pryor · November 22nd, 2007, 04:53 PM

If you lose focus in auto focus but it stays shap in manual, that's not a back focus problem--that's shooting with auto focus on. Make sure it's off. Zoom in, get your critical focus, zoom back to wide and it should be in focus. If not, then you have a back focus problem and it should be sent in for adjustment. The only way you can shoot with auto focus on is if you compose with things centered in the frame.

As far as not looking good in DV...I've shot qite a bit of DV, 24F footage for a couple of people and it looks great.

February 28th, 2007, 11:07 AM	#1
Erik Palm Regular Crew Join Date: Jan 2006 Location: Stockholm, Sweden Posts: 64	Backfocus problem? I work as a videojournalist and have a A1 PAL version. I had problems with blurry faces shooting 4:3 SD just like Jan Luethje. Haven´t looked at HDV on a monitor yet. http://www.dvinfo.net/conf/showthread.php?t=87214 My professional collegues, that shoot 2/3' P2 cameras thinks the camera has a backfocus problem, similar to the one of Sony PD150, after testing it. Has anybody else noticed backfocus problems? (Test it by for instance focusing manually close up on somebodys eyes, zoom ut while leaving the focus unchanged. For me, the focus ended up on the ears or shoulder after zooming out instead of the eyes. The picture was blurry too) Thanks Erik

March 10th, 2007, 04:32 AM	#7
Erik Palm Regular Crew Join Date: Jan 2006 Location: Stockholm, Sweden Posts: 64	Send it back to Canon for check I let you know what Canon says. /Erik

March 29th, 2007, 08:17 AM	#8
Lynn King Tourist Join Date: Jan 2007 Location: south bend, in Posts: 4	returned G1 I had the same back focus problem with my G1 and returned it. I've had no problems with the new G1. You should send your camera back immediately.

March 29th, 2007, 01:20 PM	#9
Erik Palm Regular Crew Join Date: Jan 2006 Location: Stockholm, Sweden Posts: 64	I had it repaired Canon adjusted the focus, now it seems better. Only tested a few minutes the other day. But I'm not that impressed by the DV quality. Tricky too make it look good. I think I shoot HDV and downconvert only - takes some time to process though. /Erik

February 28th, 2007, 02:10 PM	#2
Bill Pryor Contributor Join Date: Jan 2003 Location: Kansas City, MO Posts: 4,449	Back focus was the first thing I checked out, and mine is fine. It could be you have one with a problem. I would go back to where you bought it asap.

March 3rd, 2007, 12:12 PM	#3
John Brinks Regular Crew Join Date: Jan 2007 Location: Phoenix Az Posts: 69	I thought the a1, had the type of lens that needs to be refocused after zooming?

March 3rd, 2007, 12:15 PM	#4
Bill Pryor Contributor Join Date: Jan 2003 Location: Kansas City, MO Posts: 4,449	No. You use it like any other lens--zoom in and get critical focus, then zoom back to where you want to be for the shot. If it doesn't stay sharp, there's a problem.

March 3rd, 2007, 01:44 PM	#5
John Brinks Regular Crew Join Date: Jan 2007 Location: Phoenix Az Posts: 69	Mine definitely needs to be refocused after zooming... if i go from a wide shot to a closeup, the focus changes completely.

March 29th, 2007, 01:32 PM	#10
Eric Weiss Major Player Join Date: Mar 2007 Location: Philly,PA Posts: 360	can you upload a sample of said DV?

November 22nd, 2007, 12:26 PM	#11
Randy Panado Major Player Join Date: Oct 2007 Location: Honolulu, HI Posts: 643	Mines displaying a back focus problem as well. I'm going to take it into Canon to see what they say about it. I guess for now I'll have to live with manual focus for this next gig I have coming up.

November 22nd, 2007, 04:53 PM	#12
Bill Pryor Contributor Join Date: Jan 2003 Location: Kansas City, MO Posts: 4,449	If you lose focus in auto focus but it stays shap in manual, that's not a back focus problem--that's shooting with auto focus on. Make sure it's off. Zoom in, get your critical focus, zoom back to wide and it should be in focus. If not, then you have a back focus problem and it should be sent in for adjustment. The only way you can shoot with auto focus on is if you compose with things centered in the frame. As far as not looking good in DV...I've shot qite a bit of DV, 24F footage for a couple of people and it looks great.