XL2 and EF Lens Adapter / EF Lenses / EOS Lens

Andrew Khalil · May 24th, 2006, 10:33 PM

I don't think the XL2's sensitivity is much different from your 20D (actually I think the 20D is more sensitive because of the larger sensor). It has more to do with your shutter speed - you'd never use a shutter speed of 1/60 outside on a bright sunny say when you're taking stills - more like 1/1000 or something really high which will also allow you to keep your iris wider and freeze motion. Also, with that particular lens, you need to use high shutter speeds to avoid blur from image shake which isn't really an issue when shooting video.

Try out some ND filters and you should be good to keep shooting - I have the same lens and I think it's my favorite stills lens that I own but I havn't attached it to my XL2 yet.

Tom Hardwick · May 25th, 2006, 12:54 AM

Steer well clear of f/32 David! In fact for quality images with a 1/3" chipped camcorder, don't stop down below f/5.6. So yes, use lots of ND (but don't stack filters).

tom.

David Fix · May 25th, 2006, 10:58 AM

Well, DUH!!!! Of course, I'm shooting at 1/60 of a second so I'm going to have to stop down pretty far.

The lens is an f4 so if I don't close down past f5.6 that gives me a limited range to work in. Are f8 or f16 so bad? I've often heard that that lenses generally work best a couple stops down from wide open or is there an issue with the small 1/3" chips in miniDV? I've not heard of a similar concern with digital still cameras.

Tom Hardwick · May 25th, 2006, 11:11 AM

It's all to do with chip sizes and focal lengths. The smaller the chips and the shorter the focal length, the worse diffraction losses become, and if you shoot at f/4 with your XL2 and compare it with the same shot at f/16 you'll know just what I mean. It has nothing whatsoever to do with Mini DV.

Ansel Adams shot onto huge 'chips' measuring 10" x 8", so he could happily use apertures like f/32. We're shoting onto tiny chips 4.4 mm wide, so beware tiny apertures much more than large apertures.

Yes, you'll have a limited range. But so to does the PDX10 and the HC1/A1 - neither camera stops down below f/4.5 unless all the internal ND gets used up first.

Moral: Use ND filteration, lots of it. Beware higher shutter speeds because it leads to CCD smear and jittery footage that contains movement.

tom.

David Fix · May 25th, 2006, 12:15 PM

If I understand correctly shorter focal length = more diffraction. I'm using a 70-200mm lens (highly multiplied by the 1/3" chips) so does that help me much?

Thanks, Dave

Andrew Khalil · May 25th, 2006, 12:30 PM

I don't know if I'm right or wrong about this, so please try using different aperture values and see what the results look like, but I don't think the rule of keeping your aperture very open applies with EF lenses for the simple reason that they are capable of stopping down much more (f/32) like you said so you'll have more room to play around before diffraction occurs.

The XL2 lens can't go above F/16 which is its minimum aperture, but when a lens can go to f/32, it's likely to perform reasonably well at f/16 and possibly higher values as well. The only problem is at these apertures, a lot will be in focus because of the smaller sensor/narrower aperture, so make sure the lens adapter and any filters are clean and free of dust or you'll see it on the image.

But again, I'd try it out and see if there is any image quality loss - what did the image look like at f/32?

Tom Hardwick · May 25th, 2006, 12:30 PM

It certainly dees help you Dave. I'm using a focal length of 2.25 mm with my 0.5x converter in place, and I'm very aware of the difraction sofrening. In fact Sony make warnings about it in their Z1 and FX1 instruction books, and many modern camcorders won't stop down below f/8 for this very reason.

Your 70 - 200 focal length is unaffected by chip dimensions, but if you're worried it's pretty easy to do some controlled tests. Talk into the mic as you stop the lens down, as using the 'display' function on replay to give you a readout is often less reliable. A lot of displays stop at f/11 (the one on my Sony VX2k does) yet the camera will film at f/16. f/22 and f/32 before the blades close. All these read out as f/11.

tom.

Tom Hardwick · May 25th, 2006, 12:42 PM

Sorry Andrew, but you're wrong. EF lenses are designed for huge chips (36 mm wide - ten times the width or ours) and such areas of real estate make small apertures much more acceptable and diffraction far less of a problem.

But you're spot on to suggest that Dave does some tests of his own. I've really surprised people I teach when I tell them these facts - invariably they've come from 35 mm cameras where f/16 is commomplace and they're often quite adamant that f/16 will be sharper than f/1.6. It never is with tiny chips; it's the laws of optics.

tom.

David Fix · May 25th, 2006, 12:53 PM

Here's a link to an article which explains Tom's point in a little more depth. http://www.tvtechnology.com/features...08.17.05.shtml

Tom Hardwick · May 25th, 2006, 12:56 PM

Well spotted, Dave.

Andrew Khalil · May 25th, 2006, 01:15 PM

okay, I see where I was wrong - thanks for the article - it really helped explain the issue. I think this would make a good experiment except I don't have an EF adapter, otherwise I'd pull it off.

Andy Joyce · May 26th, 2006, 07:04 PM

Quote:

Originally Posted by Ed Bicker

Hello Andy,
Can you tell me where you got the handle and parabolic dish for the mike that you made?

Hey Ed,

Check-out this thread:

http://dvinfo.net/conf/showthread.php?t=66536

David Fix · May 27th, 2006, 02:26 PM

I did some quick tests outside with the standard 20x lens on my xl2 (which, interestingly enough, closes up past after f11) and maybe saw a difference between f2.8 and f8, but I need to do more tests. Frankly I am underwhelmed by miniDV in general, all the more reason to try to find its sweet spot I suppose. I couldn't really test the 70-200 lens as I would need a range of ND to test outdoors.

Tom Hardwick · May 28th, 2006, 04:37 AM

''underwhelmed by miniDV in general'', Dave? Gollygosh, I smack my forehead in disbelief at what my 6 year old VX2000 puts up there on the big 34'' Sony Trinitron. Astounding quality images from a camera that's so cheap, small, light and reliable.

Of course it sure helps if you work with and understand the limitations of the system. To know the value of expensive tripod heads, to keep well away from small apertures, to go for big bold close-ups whenever possible and to master your DVDs at the highest bit rate your player can handle.

Having come from (more expensive) Hi-8 equipment many years ago, I can say hand on heart that I'm one of the overwhelmed.

tom.

David Fix · May 28th, 2006, 04:00 PM

I worked in TV news for 25 years and was used to 2/3" chip cameras.

I'm doing wildlife photography alot now and I have run into problems with the XL2. I hooked up a shotgun (Sennheiser ME-80) and found I couldn't turn the volume up over 1/2 before preamp noise become objectionable. Running the mic into the line inputs thru a Shure FP-24 solved that and other problems like poor headphone monitoring and poor camera balance. If you shoot anything green with a lot of detail (hard to avoid in nature photography) there is crawl in those areas. This form and others have long threads on these issues. Shoot and mic people indoors with decent lighting and the camera works fine.

That being said, I'm too old to be lugging an betacam thru the woods even if I could afford one. Barry Braverman opens his book "Video Shooter" with "I hate DV!" (and what it's done to the business). He concedes that he and we have to live with it and adapt, and that I grant. I just want to work on the formats problems, problems that some seem not to encounter or perceive.

May 25th, 2006, 12:15 PM	#215
David Fix New Boot Join Date: Feb 2006 Posts: 20	re: focal length If I understand correctly shorter focal length = more diffraction. I'm using a 70-200mm lens (highly multiplied by the 1/3" chips) so does that help me much? Thanks, Dave

May 24th, 2006, 10:33 PM	#211
Andrew Khalil Major Player Join Date: Jun 2005 Posts: 424	I don't think the XL2's sensitivity is much different from your 20D (actually I think the 20D is more sensitive because of the larger sensor). It has more to do with your shutter speed - you'd never use a shutter speed of 1/60 outside on a bright sunny say when you're taking stills - more like 1/1000 or something really high which will also allow you to keep your iris wider and freeze motion. Also, with that particular lens, you need to use high shutter speeds to avoid blur from image shake which isn't really an issue when shooting video. Try out some ND filters and you should be good to keep shooting - I have the same lens and I think it's my favorite stills lens that I own but I havn't attached it to my XL2 yet.

May 25th, 2006, 12:54 AM	#212
Tom Hardwick Inner Circle Join Date: Mar 2003 Location: Billericay, England UK Posts: 4,711	Steer well clear of f/32 David! In fact for quality images with a 1/3" chipped camcorder, don't stop down below f/5.6. So yes, use lots of ND (but don't stack filters). tom.

May 25th, 2006, 10:58 AM	#213
David Fix New Boot Join Date: Feb 2006 Posts: 20	Well, DUH!!!! Of course, I'm shooting at 1/60 of a second so I'm going to have to stop down pretty far. The lens is an f4 so if I don't close down past f5.6 that gives me a limited range to work in. Are f8 or f16 so bad? I've often heard that that lenses generally work best a couple stops down from wide open or is there an issue with the small 1/3" chips in miniDV? I've not heard of a similar concern with digital still cameras.

May 25th, 2006, 11:11 AM	#214
Tom Hardwick Inner Circle Join Date: Mar 2003 Location: Billericay, England UK Posts: 4,711	It's all to do with chip sizes and focal lengths. The smaller the chips and the shorter the focal length, the worse diffraction losses become, and if you shoot at f/4 with your XL2 and compare it with the same shot at f/16 you'll know just what I mean. It has nothing whatsoever to do with Mini DV. Ansel Adams shot onto huge 'chips' measuring 10" x 8", so he could happily use apertures like f/32. We're shoting onto tiny chips 4.4 mm wide, so beware tiny apertures much more than large apertures. Yes, you'll have a limited range. But so to does the PDX10 and the HC1/A1 - neither camera stops down below f/4.5 unless all the internal ND gets used up first. Moral: Use ND filteration, lots of it. Beware higher shutter speeds because it leads to CCD smear and jittery footage that contains movement. tom.

May 25th, 2006, 12:30 PM	#216
Andrew Khalil Major Player Join Date: Jun 2005 Posts: 424	I don't know if I'm right or wrong about this, so please try using different aperture values and see what the results look like, but I don't think the rule of keeping your aperture very open applies with EF lenses for the simple reason that they are capable of stopping down much more (f/32) like you said so you'll have more room to play around before diffraction occurs. The XL2 lens can't go above F/16 which is its minimum aperture, but when a lens can go to f/32, it's likely to perform reasonably well at f/16 and possibly higher values as well. The only problem is at these apertures, a lot will be in focus because of the smaller sensor/narrower aperture, so make sure the lens adapter and any filters are clean and free of dust or you'll see it on the image. But again, I'd try it out and see if there is any image quality loss - what did the image look like at f/32?

May 25th, 2006, 12:30 PM	#217
Tom Hardwick Inner Circle Join Date: Mar 2003 Location: Billericay, England UK Posts: 4,711	It certainly dees help you Dave. I'm using a focal length of 2.25 mm with my 0.5x converter in place, and I'm very aware of the difraction sofrening. In fact Sony make warnings about it in their Z1 and FX1 instruction books, and many modern camcorders won't stop down below f/8 for this very reason. Your 70 - 200 focal length is unaffected by chip dimensions, but if you're worried it's pretty easy to do some controlled tests. Talk into the mic as you stop the lens down, as using the 'display' function on replay to give you a readout is often less reliable. A lot of displays stop at f/11 (the one on my Sony VX2k does) yet the camera will film at f/16. f/22 and f/32 before the blades close. All these read out as f/11. tom.

May 25th, 2006, 12:42 PM	#218
Tom Hardwick Inner Circle Join Date: Mar 2003 Location: Billericay, England UK Posts: 4,711	Sorry Andrew, but you're wrong. EF lenses are designed for huge chips (36 mm wide - ten times the width or ours) and such areas of real estate make small apertures much more acceptable and diffraction far less of a problem. But you're spot on to suggest that Dave does some tests of his own. I've really surprised people I teach when I tell them these facts - invariably they've come from 35 mm cameras where f/16 is commomplace and they're often quite adamant that f/16 will be sharper than f/1.6. It never is with tiny chips; it's the laws of optics. tom.

May 25th, 2006, 12:53 PM	#219
David Fix New Boot Join Date: Feb 2006 Posts: 20	Here's a link to an article which explains Tom's point in a little more depth. http://www.tvtechnology.com/features...08.17.05.shtml

May 25th, 2006, 12:56 PM	#220
Tom Hardwick Inner Circle Join Date: Mar 2003 Location: Billericay, England UK Posts: 4,711	Well spotted, Dave.

May 25th, 2006, 01:15 PM	#221
Andrew Khalil Major Player Join Date: Jun 2005 Posts: 424	okay, I see where I was wrong - thanks for the article - it really helped explain the issue. I think this would make a good experiment except I don't have an EF adapter, otherwise I'd pull it off.

May 27th, 2006, 02:26 PM	#223
David Fix New Boot Join Date: Feb 2006 Posts: 20	I did some quick tests outside with the standard 20x lens on my xl2 (which, interestingly enough, closes up past after f11) and maybe saw a difference between f2.8 and f8, but I need to do more tests. Frankly I am underwhelmed by miniDV in general, all the more reason to try to find its sweet spot I suppose. I couldn't really test the 70-200 lens as I would need a range of ND to test outdoors.

May 28th, 2006, 04:37 AM	#224
Tom Hardwick Inner Circle Join Date: Mar 2003 Location: Billericay, England UK Posts: 4,711	''underwhelmed by miniDV in general'', Dave? Gollygosh, I smack my forehead in disbelief at what my 6 year old VX2000 puts up there on the big 34'' Sony Trinitron. Astounding quality images from a camera that's so cheap, small, light and reliable. Of course it sure helps if you work with and understand the limitations of the system. To know the value of expensive tripod heads, to keep well away from small apertures, to go for big bold close-ups whenever possible and to master your DVDs at the highest bit rate your player can handle. Having come from (more expensive) Hi-8 equipment many years ago, I can say hand on heart that I'm one of the overwhelmed. tom.

May 28th, 2006, 04:00 PM	#225
David Fix New Boot Join Date: Feb 2006 Posts: 20	I worked in TV news for 25 years and was used to 2/3" chip cameras. I'm doing wildlife photography alot now and I have run into problems with the XL2. I hooked up a shotgun (Sennheiser ME-80) and found I couldn't turn the volume up over 1/2 before preamp noise become objectionable. Running the mic into the line inputs thru a Shure FP-24 solved that and other problems like poor headphone monitoring and poor camera balance. If you shoot anything green with a lot of detail (hard to avoid in nature photography) there is crawl in those areas. This form and others have long threads on these issues. Shoot and mic people indoors with decent lighting and the camera works fine. That being said, I'm too old to be lugging an betacam thru the woods even if I could afford one. Barry Braverman opens his book "Video Shooter" with "I hate DV!" (and what it's done to the business). He concedes that he and we have to live with it and adapt, and that I grant. I just want to work on the formats problems, problems that some seem not to encounter or perceive.