When and when not to use the lens hood? at DVinfo.net

Bo Shaheen · January 5th, 2004, 02:28 PM

I've noticed with some of the shooting I've done with my xl1s, that I can see part of my lens hood in all four corners when I play back my footage on a tv or computer. It's not horribly noticeable, but definately bothers me. It's reall fuzzy. I think it might have something to do with shooting in low light.
Can somebody tell me when to use and when not to use your lens hood? Thanks!

Rob Lohman · January 5th, 2004, 04:07 PM

Are you sure? Aren't you seeing something other like a filter? I
can't remember ever seeing my hood showing up in any of my
footage! It's basically always on my XL1S.

Frank Granovski · January 5th, 2004, 04:31 PM

Bo, you could get a larger/wider lens hood.

Bo Shaheen · January 5th, 2004, 11:17 PM

Rob, you think it might be my screw-on UV filter? I've got one on my lens? Maybe it is.
I've noticed that the few clips I have with the fuzzy, dark corners were shot in low light.

Adam Burtle · January 6th, 2004, 12:44 AM

i've never seen the hood in mine at all.. i would shoot some footage with the filter off..

also it might be the tapes you're using too, if you're switching media.

Frank Granovski · January 6th, 2004, 12:56 AM

It shouldn't be because of the tape.

Ken Tanaka · January 6th, 2004, 01:39 AM

Bo,
The only way the lens hood could encroach on your image is if it's improperly mounted. Remove it and carefully remount it. It must be fully seated with a twist. The Canon insignia should be on top.

Filters can encraoch on the image, causing a vignetting effect. This, however, is generally only an issue when stacking two or more screw-ons and shooting at the widest angle. This should be trivial problem for you to diagnose. Take the filters off and test.

Adam Burtle · January 6th, 2004, 04:50 AM

<<<-- Originally posted by Frank Granovski : It shouldn't be because of the tape. -->>>

i have had issues with using different brands of tapes and the 2nd brand (sony) causing a "shadowing" towards the outer edge of the camera. i have also seen this issue in GL2's before. again, i think it's his filter, but if it's not.. a head cleaning and running 1 brand of tape may fix it.

Don Palomaki · January 6th, 2004, 05:26 AM

I cannot imagne how tape could induce corner vignetting in a digital system. Head and tape problems cause digital errors - block and mosaic type effects in the image.

Effect of a filter stack or other external device is the most likely cause. It wil be more visible on a computer monitor due to lack of ovescan. A second less likely possibility is an internal lens defect.

However, all lenses have some fall-offf toward the corners, this is most apparent with very flat subjects, e.g., somewhat underexposed plain white walls.

Adam Burtle · January 6th, 2004, 12:22 PM

Don and Frank, this is the issue i was referring to. It is more visible in low light. It is due to switching tape media brands as different medias use different tape lubes that can react and gum up the heads. I have seen this issue in several camera, and it is a fairly well known one.

12mb mpeg2 clip, interlaced and no correction or effects of any kind done to it. Watch the top left and right corners, note "blur" does not correlate to zoom at all (as it appears when wide and tight)

http://www.adamgeek.com/vignette.mpg

Ken Tanaka · January 6th, 2004, 02:27 PM

Adam,
I do not believe that the vignetting in the clip has any relation to switching tape brands or to tape at all. It is a common edge light fall-off phenomenon of all lenses, video and photo. It is related principally to the lens' design and to the iris setting.

We've discussed this exhaustively with regard to the GL2 at this thread.

Contaminated heads cause a completely different, and very distinct, problem.

Andre De Clercq · January 6th, 2004, 03:53 PM

As far as I know the XL1s has interchangeable lenses. Are you using the standard ones together with the standard lenshood??

Gints Klimanis · January 6th, 2004, 04:26 PM

What you describe sounds like vignetting, but I've also seen the hood of my Canon WD-58 in one corner (upper left) of my video clips. In that case, the hood was mounted with the incorrect rotation.

Adam Burtle · January 6th, 2004, 05:59 PM

<<<-- Originally posted by Ken Tanaka : Adam,
I do not believe that the vignetting in the clip has any relation to switching tape brands or to tape at all. It is a common edge light fall-off phenomenon of all lenses, video and photo. It is related principally to the lens' design and to the iris setting.

We've discussed this exhaustively with regard to the GL2 at this thread.

Contaminated heads cause a completely different, and very distinct, problem. -->>>

Interesting.. i'll read the link in a sec. However, i have only had this problem once, it was after shooting using sony instead of Panasonic media, and after a head cleaning the issue was resolved. Furthermore, i had shot in that exact same location, from 3pm untill 10pm on nearly a dozen occasions, and this was the only one to cause the blur i posted. Perhaps it wasnt the tape issue and by chance i've never been able to replicate it.. i dunno.

March 17th, 2004, 09:36 PM

I had this problem once when I was using a wide-angle lens. Didn't pay attention and unless I zoomed in a little from full, you could see the edges of the lens body in the corners. They were clipped when viewing on TV, thank god, but really noticeable and irritating in the NLE.

January 5th, 2004, 02:28 PM	#1
Bo Shaheen New Boot Join Date: Feb 2003 Location: St. George, Utah Posts: 5	When and when not to use the lens hood? I've noticed with some of the shooting I've done with my xl1s, that I can see part of my lens hood in all four corners when I play back my footage on a tv or computer. It's not horribly noticeable, but definately bothers me. It's reall fuzzy. I think it might have something to do with shooting in low light. Can somebody tell me when to use and when not to use your lens hood? Thanks!

January 5th, 2004, 04:07 PM	#2
Rob Lohman RED Code Chef Join Date: Oct 2001 Location: Holland Posts: 12,514	Are you sure? Aren't you seeing something other like a filter? I can't remember ever seeing my hood showing up in any of my footage! It's basically always on my XL1S. __________________ Rob Lohman, visuar@iname.com DV Info Wrangler & RED Code Chef Join the DV Challenge \| Lady X Search DVinfo.net for quick answers \| Buy from the best: DVinfo.net sponsors

January 6th, 2004, 01:39 AM	#7
Ken Tanaka Retired DV Info Net Almunus Join Date: Dec 2001 Location: Chicago, IL Posts: 6,943	Bo, The only way the lens hood could encroach on your image is if it's improperly mounted. Remove it and carefully remount it. It must be fully seated with a twist. The Canon insignia should be on top. Filters can encraoch on the image, causing a vignetting effect. This, however, is generally only an issue when stacking two or more screw-ons and shooting at the widest angle. This should be trivial problem for you to diagnose. Take the filters off and test. __________________ Lady X Films: A lady with a boring wardrobe...and a global mission. Hey, you don't have enough stuff! Buy with confidence from our sponsors. Hand-picked as the best in the business...Really! See some of my work one frame at a time: www.KenTanaka.com

January 6th, 2004, 05:26 AM	#9
Don Palomaki Wrangler Join Date: Sep 2001 Location: Northern VA Posts: 4,487	I cannot imagne how tape could induce corner vignetting in a digital system. Head and tape problems cause digital errors - block and mosaic type effects in the image. Effect of a filter stack or other external device is the most likely cause. It wil be more visible on a computer monitor due to lack of ovescan. A second less likely possibility is an internal lens defect. However, all lenses have some fall-offf toward the corners, this is most apparent with very flat subjects, e.g., somewhat underexposed plain white walls. __________________ dpalomaki@dspalomaki.com

January 6th, 2004, 02:27 PM	#11
Ken Tanaka Retired DV Info Net Almunus Join Date: Dec 2001 Location: Chicago, IL Posts: 6,943	Adam, I do not believe that the vignetting in the clip has any relation to switching tape brands or to tape at all. It is a common edge light fall-off phenomenon of all lenses, video and photo. It is related principally to the lens' design and to the iris setting. We've discussed this exhaustively with regard to the GL2 at this thread. Contaminated heads cause a completely different, and very distinct, problem. __________________ Lady X Films: A lady with a boring wardrobe...and a global mission. Hey, you don't have enough stuff! Buy with confidence from our sponsors. Hand-picked as the best in the business...Really! See some of my work one frame at a time: www.KenTanaka.com

January 5th, 2004, 04:31 PM	#3
Frank Granovski Outer Circle Join Date: May 2002 Location: Hope, BC Posts: 7,524	Bo, you could get a larger/wider lens hood.

January 5th, 2004, 11:17 PM	#4
Bo Shaheen New Boot Join Date: Feb 2003 Location: St. George, Utah Posts: 5	Rob, you think it might be my screw-on UV filter? I've got one on my lens? Maybe it is. I've noticed that the few clips I have with the fuzzy, dark corners were shot in low light.

January 6th, 2004, 12:44 AM	#5
Adam Burtle Regular Crew Join Date: Oct 2003 Location: Los Angeles, CA Posts: 173	i've never seen the hood in mine at all.. i would shoot some footage with the filter off.. also it might be the tapes you're using too, if you're switching media.

January 6th, 2004, 12:56 AM	#6
Frank Granovski Outer Circle Join Date: May 2002 Location: Hope, BC Posts: 7,524	It shouldn't be because of the tape.

January 6th, 2004, 04:50 AM	#8
Adam Burtle Regular Crew Join Date: Oct 2003 Location: Los Angeles, CA Posts: 173	<<<-- Originally posted by Frank Granovski : It shouldn't be because of the tape. -->>> i have had issues with using different brands of tapes and the 2nd brand (sony) causing a "shadowing" towards the outer edge of the camera. i have also seen this issue in GL2's before. again, i think it's his filter, but if it's not.. a head cleaning and running 1 brand of tape may fix it.

January 6th, 2004, 12:22 PM	#10
Adam Burtle Regular Crew Join Date: Oct 2003 Location: Los Angeles, CA Posts: 173	Don and Frank, this is the issue i was referring to. It is more visible in low light. It is due to switching tape media brands as different medias use different tape lubes that can react and gum up the heads. I have seen this issue in several camera, and it is a fairly well known one. 12mb mpeg2 clip, interlaced and no correction or effects of any kind done to it. Watch the top left and right corners, note "blur" does not correlate to zoom at all (as it appears when wide and tight) http://www.adamgeek.com/vignette.mpg

January 6th, 2004, 03:53 PM	#12
Andre De Clercq Major Player Join Date: Sep 2002 Location: Belgium Posts: 804	As far as I know the XL1s has interchangeable lenses. Are you using the standard ones together with the standard lenshood??

January 6th, 2004, 04:26 PM	#13
Gints Klimanis Inner Circle Join Date: Jun 2003 Location: San Jose, CA Posts: 2,222	What you describe sounds like vignetting, but I've also seen the hood of my Canon WD-58 in one corner (upper left) of my video clips. In that case, the hood was mounted with the incorrect rotation.

January 6th, 2004, 05:59 PM	#14
Adam Burtle Regular Crew Join Date: Oct 2003 Location: Los Angeles, CA Posts: 173	<<<-- Originally posted by Ken Tanaka : Adam, I do not believe that the vignetting in the clip has any relation to switching tape brands or to tape at all. It is a common edge light fall-off phenomenon of all lenses, video and photo. It is related principally to the lens' design and to the iris setting. We've discussed this exhaustively with regard to the GL2 at this thread. Contaminated heads cause a completely different, and very distinct, problem. -->>> Interesting.. i'll read the link in a sec. However, i have only had this problem once, it was after shooting using sony instead of Panasonic media, and after a head cleaning the issue was resolved. Furthermore, i had shot in that exact same location, from 3pm untill 10pm on nearly a dozen occasions, and this was the only one to cause the blur i posted. Perhaps it wasnt the tape issue and by chance i've never been able to replicate it.. i dunno.

March 17th, 2004, 09:36 PM	#15
Kevin Walsh Posts: n/a	I had this problem once when I was using a wide-angle lens. Didn't pay attention and unless I zoomed in a little from full, you could see the edges of the lens body in the corners. They were clipped when viewing on TV, thank god, but really noticeable and irritating in the NLE.