focus slipping, iris acting funny

Bill Markel · May 11th, 2002, 03:45 PM

<<<-- Originally posted by SlashRules : But unless I know my stuff is going to reach theatrical distribution, isn't what a consumer television shows me good enough? Granted there's that portion of the population with HD TVs and such, is it really that big of an issue? -->>>

Slash,

If you might be doing something for distribution with Quick Time or Windows Media it may become a problem. These formats will show everything including the problem with the black bar at the bottom of the picture.

And yes, you are not alone. I was out shooting yesterday and had the same focus problem to which you referred in your original post. I thought I was doing something wrong.

Bill

Ken Tanaka · May 11th, 2002, 07:38 PM

Slash,
Indeed, normal underscan is not an issue for material targeted at standard tv viewing. Underscan, itself, is unavoidable. But, as Bill noted, streamed or digital material will show the full frame's contents.

Also, the color viewfinder's frame is, I believe, cropped closer than the underscan borders. So unless you are careful you can easily find unintended stuff creeping into the recorded frame and not discover it until you go to post.

ja135321 · May 23rd, 2002, 03:03 PM

Haha,

Try going all the way wide in the 3x and you can get the lens hood in the frame.

I know you can edit the frame in post, but then if it's focus critical in post production you might have a problem.

Chris Hurd · May 23rd, 2002, 03:27 PM

I've shot extensively with the 3x lens out all the way wide and have *never* had the lens hood appear in frame. The hood which comes with the 3x is shaped differently than the hood on the standard 16x; if you use the wrong hood then I can see how this would be the problem. But as to the 3x hood appearing in the frame, that's a new one on me, I have never experienced that after much shooting all the way wide with that 3x lens.

Ken Tanaka · May 23rd, 2002, 03:37 PM

Same here. As long as the 3x hood is mounted properly it cannot possibly creeep into the frame whatsoever. That said, it is possible to mismount the hood, particularly if you're in a hurry and not paying close attention. Just make sure that the set screw slides into the lens' channel and that you lock it down.

Dave Morrison · May 28th, 2002, 06:54 AM

Interesting thread and some good info. However, Chris Hurd's quote at the beginning of this thread contained the dreaded word *all*:

<On the second issue, this is *perfectly normal* for a zoom lens... it will have one certain maximum aperture at the wide end, and another certain maximum aperture, not as open, at the telephoto end. *All* zoom lenses are like this, on video cameras and still cameras alike. You have to get into an *extremely expensive* professional zoom lens costing many, many thousands of dollars to get around this issue.>

I don't know if the *'s were the qualifier here, Chris, but I'll have to take issue with you up to a point. In my still photography gear (Nikon) all three of my zooms (17-35, 28-70, 80-210) are constant f2.8 across their entire zoom range.

This has been a great thread for still shooters like me who are being moved into more and more video work for our employers...thanks guys. I'm anxious to see some head-to-head comparisons of the zoom through Wide adapters as I'm feeling very limited (visually) by what our company's XL1 is capable of with the standard lens....I'm spoiled by my Nikon gear ;)

dave

Chris Hurd · May 28th, 2002, 08:12 AM

My apologies Dave, I should have limited my statement to the realm of prosumer video zoom lenses only. Thanks,

Josh Bass · May 28th, 2002, 11:29 AM

I remember someone saying that the XL1s 16x manual lens didn't have that issue (with the aperature having a different maximum setting at the lens's wide angle than from the lens's telephoto). Is it BS?

May 28th, 2002, 03:33 PM

The 16x Manual/Servo lens remains at f1.6 thru the entire zoom range, it's not BS because I have one and use it.

Josh Bass · May 28th, 2002, 11:54 PM

Hey hey now. I wasn't accusing anyone. Just asking. This is after all, the internet, and there is known to be much incorrect information floating around.

Chris Hurd · May 29th, 2002, 12:05 AM

No problem, Don is just confirming something that sure looked like mis-information the way I originally wrote it. I should be more careful.

Josh Bass · May 29th, 2002, 02:56 AM

Cool. It's just one more reason for me to buy the lens, which I'm already planning to do.

Kai Leibrandt · May 29th, 2002, 07:09 PM

and a good choice it will be. Like a few others, my fav extra I got for my non-s XL1 is the 16x manual. Focussing _is_ that much easier with it on, and I hardly ever miss the AF functionality (but then I never do guerilla shooting).

Kai.

May 11th, 2002, 07:38 PM	#47
Ken Tanaka Retired DV Info Net Almunus Join Date: Dec 2001 Location: Chicago, IL Posts: 6,943	Slash, Indeed, normal underscan is not an issue for material targeted at standard tv viewing. Underscan, itself, is unavoidable. But, as Bill noted, streamed or digital material will show the full frame's contents. Also, the color viewfinder's frame is, I believe, cropped closer than the underscan borders. So unless you are careful you can easily find unintended stuff creeping into the recorded frame and not discover it until you go to post. __________________ 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

May 23rd, 2002, 03:03 PM	#48
ja135321 Regular Crew Join Date: Feb 2002 Location: Los Angeles, CA Posts: 90	underscan Haha, Try going all the way wide in the 3x and you can get the lens hood in the frame. I know you can edit the frame in post, but then if it's focus critical in post production you might have a problem.

May 23rd, 2002, 03:27 PM	#49
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,366 Images: 513	I've shot extensively with the 3x lens out all the way wide and have never had the lens hood appear in frame. The hood which comes with the 3x is shaped differently than the hood on the standard 16x; if you use the wrong hood then I can see how this would be the problem. But as to the 3x hood appearing in the frame, that's a new one on me, I have never experienced that after much shooting all the way wide with that 3x lens. __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

May 23rd, 2002, 03:37 PM	#50
Ken Tanaka Retired DV Info Net Almunus Join Date: Dec 2001 Location: Chicago, IL Posts: 6,943	Same here. As long as the 3x hood is mounted properly it cannot possibly creeep into the frame whatsoever. That said, it is possible to mismount the hood, particularly if you're in a hurry and not paying close attention. Just make sure that the set screw slides into the lens' channel and that you lock it down. __________________ 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

May 28th, 2002, 08:12 AM	#52
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,366 Images: 513	My apologies Dave, I should have limited my statement to the realm of prosumer video zoom lenses only. Thanks, __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

May 11th, 2002, 03:45 PM	#46
Bill Markel Regular Crew Join Date: Jan 2002 Location: Sicklerville, NJ Posts: 59	<<<-- Originally posted by SlashRules : But unless I know my stuff is going to reach theatrical distribution, isn't what a consumer television shows me good enough? Granted there's that portion of the population with HD TVs and such, is it really that big of an issue? -->>> Slash, If you might be doing something for distribution with Quick Time or Windows Media it may become a problem. These formats will show everything including the problem with the black bar at the bottom of the picture. And yes, you are not alone. I was out shooting yesterday and had the same focus problem to which you referred in your original post. I thought I was doing something wrong. Bill

May 28th, 2002, 06:54 AM	#51
Dave Morrison Major Player Join Date: May 2002 Location: West Central Florida Posts: 762	Interesting thread and some good info. However, Chris Hurd's quote at the beginning of this thread contained the dreaded word all: <On the second issue, this is perfectly normal for a zoom lens... it will have one certain maximum aperture at the wide end, and another certain maximum aperture, not as open, at the telephoto end. All zoom lenses are like this, on video cameras and still cameras alike. You have to get into an extremely expensive professional zoom lens costing many, many thousands of dollars to get around this issue.> I don't know if the *'s were the qualifier here, Chris, but I'll have to take issue with you up to a point. In my still photography gear (Nikon) all three of my zooms (17-35, 28-70, 80-210) are constant f2.8 across their entire zoom range. This has been a great thread for still shooters like me who are being moved into more and more video work for our employers...thanks guys. I'm anxious to see some head-to-head comparisons of the zoom through Wide adapters as I'm feeling very limited (visually) by what our company's XL1 is capable of with the standard lens....I'm spoiled by my Nikon gear ;) dave

May 28th, 2002, 11:29 AM	#53
Josh Bass Slash Rules! Join Date: Apr 2002 Location: Houston, Texas Posts: 5,472	I remember someone saying that the XL1s 16x manual lens didn't have that issue (with the aperature having a different maximum setting at the lens's wide angle than from the lens's telephoto). Is it BS? __________________ The Bass' camerawork The Bass on IMDB

May 28th, 2002, 03:33 PM	#54
Guest Posts: n/a	The 16x Manual/Servo lens remains at f1.6 thru the entire zoom range, it's not BS because I have one and use it.

May 28th, 2002, 11:54 PM	#55
Josh Bass Slash Rules! Join Date: Apr 2002 Location: Houston, Texas Posts: 5,472	Hey hey now. I wasn't accusing anyone. Just asking. This is after all, the internet, and there is known to be much incorrect information floating around. __________________ The Bass' camerawork The Bass on IMDB

May 29th, 2002, 12:05 AM	#56
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,366 Images: 513	No problem, Don is just confirming something that sure looked like mis-information the way I originally wrote it. I should be more careful. __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

May 29th, 2002, 02:56 AM	#57
Josh Bass Slash Rules! Join Date: Apr 2002 Location: Houston, Texas Posts: 5,472	Cool. It's just one more reason for me to buy the lens, which I'm already planning to do. __________________ The Bass' camerawork The Bass on IMDB

May 29th, 2002, 07:09 PM	#58
Kai Leibrandt Regular Crew Join Date: Apr 2002 Location: Munich, Germany Posts: 70	and a good choice it will be. Like a few others, my fav extra I got for my non-s XL1 is the 16x manual. Focussing _is_ that much easier with it on, and I hardly ever miss the AF functionality (but then I never do guerilla shooting). Kai.