EF Lens adapter / EF Lenses / EOS Lens

Jeff Donald · May 23rd, 2003, 10:56 PM

It's pretty well acknowledged that EOS EF lenses are sharper. More goes into sharpness than resolution. EOS EF lenses don't have to be 7.2X (difference in chip sizes) sharper. Resolution is target size independent.

I have the XL EF adapter and frequently use many of my EOS lenses on the XL1. The difference is very noticeable to me. If you search the topic you'll find that I'm not alone in my opinion.

Charles Papert · May 24th, 2003, 01:55 AM

Hmm errr hmm...

Jeff, I haven't used the Canon EOS setup but I am pretty sure I understand what it does in terms of utilizing the center section of the lens to fill the DV target, please correct me if I am wrong.

If this is the case, the swing and tilt effect would be very greatly MINIMIZED for a DV setup. I used a 35mm setup on a 16mm camera a few times and found I had to rack the tilt all the way and shoot wide open to get any real effect, and it was much less than if it had been on a 35mm camera. If you think about it, the further from the center, the further out of focus you can get, so if you are only using the center...

Do you think it might be more accurate to describe this effect in terms of manipulating the plane of focus rather than the depth of field...?

Jeff Donald · May 24th, 2003, 07:06 AM

The way a tilt or shift lens works (any large format lens) is with excess coverage of the target area (CCD chip). What is excess coverage? Imagine your target area (24mm X 36mm film, 1/3 inch chip etc.) and then draw a circle much larger than the target. A typical 35mm T/S lens will have 10mm to 14mm extra coverage on the top, bottom and both sides. The coverage area would be much larger than a 1/3 inch chip (4.8mm X 3.6mm). The image circle of the Canon EOS EF 24mm T/S is 58.6mm dia.

The image can be shifted (not tilted) up, down and side to side. The shift mechanism is used to control perspective, i.e. make parallel lines parallel..

The tilt mechanism is used to control DOF. This is accomplished by the tilt controls (on the EOS lens, knobs are rotated). By following the Scheimpflug Principal DOF, can be controlled.. Rather than restate the principal, those interested should download this PDF from the Arri site. The title of the document is Tilt Focus and deals with the principals involved here. It is a 256k document and you'll need Adobe Acrobat Reader.

Most of the article talks about tilt (extending DOF). Well, small chip DV users have plenty of DOF and what we're interested in is Swing. A current trend is to call Swing, Negative Tilt. They mean the same. On page 15 are diagrams of no tilt and tilt. On page 16 is a diagram of negative tilt, or swing. The DOF is actually decreased, not just moved or shifted from side to side. Yes, it is greater on one side than the other.

Charles, your question is basically my question. Would the greater amount of excess coverage help reduce the extreme DOF on smaller formats? Your experience with it on 16mm would seem to indicate that it wouldn't be enough control. Do you recall what focal length lens you used?

The principal works. I made extensive use of it on my view cameras. So, the question remains, how effective are T/S lenses on DV?

Joseph George · May 24th, 2003, 10:56 AM

Isn't there an EOS lens w/F1.0? I think that there is a 50 mm? one. It will be an extreme telephoto on the camcorder, but would have shallow enough DOF for nice film look; but would probably be limited to outdoors work.

Corey Doyle · June 5th, 2003, 10:45 AM

I saw this on eBay:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2933116229&category=undefined

I would love to buy it because I've always wanted the option of using different lenses but I've never heard of this, I thought only Canon made an adapter. And it claims that the adapter only magnifies the image by 2x! Has anyone here used it? One more thing: I'm assuming if I bought this and used Canon EF lenses, it would produce a higher quality image than just using the 16x lens that came with the xl1s. Am I right?

Thanks!
Corey

Chris Hurd · June 5th, 2003, 04:48 PM

This adapter comes from Barrett Bilotta at XL1 Soultions. His products were showcased in the Canon booth at NAB. He's sending us a unit for review; you'll see more about this on the Watchdog pretty soon. Don't want to buy through Ebay? He sells direct. And he gets an endorsement from DV Info.

Dan Locke-Wheaton · June 9th, 2003, 04:00 AM

I am looking to purchase a XL1s and I am just researching the different abilities of the camera, so I apologise for my ignorance.

I have obviously read about the abilities of the camera to shoot using Canon EF Lenses.

My questions are:

1"Can you use these lenses for filming or are they only usefull for taking digital stills with the camera.

2"If you can use these lenses for filming is there a problem with image shake like you get when you zoom out fully on basic set-ups"

3" If they can only be used for stills what is the quality like and what options do you have.

Thanks,
Dan

Adrian Douglas · June 9th, 2003, 06:23 AM

Dan,

You can use the EF lenses/adaptor for regular shooting. However, there is a multiplication factor of 7.2 which means a 100mm lens becomes a 720mm etc. This is great if you are shooting wildlife or surfing but can be a problem if you want to uses them in regular shooting situations.

Quality wise I borrowed an adapter from a friend and tried it with my 70-200/2.8L. I shot some surf footage and was totally stoked with the results. The shots were noticabley sharper than the 16x XL lens and at 500-1440 the focal length was awesome. Image shake wasn't a problem but a good tripod and fluid head are a must.

Many people here shoot wildlife with the EF lenses and swear by the 100-400 and a few the 35-350. None are by any means "cheap" alternatives especially once you include the cost of the adapter.

The bottom line is if you need extreme focal lengths then you can't go past the EF lenses and adapter. If you just want sharper glass for regular shooting then consider the 16x manual servo lens.

Steve Siegel · June 12th, 2003, 06:38 PM

Using EF zoom lenses you will get shake even with the best tripod and head in a breeze over 10 mph. Lightly touching the camcorder will do the same. You may not even notice the shake in the viewfinder, but it's enough to be noticable at home on TV. It's just a function of the 7.2 magnification factor. The lenses are superb, however, and well worth the minor inconvenience.

Adrian Seah · June 13th, 2003, 04:26 PM

I somehow find it hard to believe the claims on the adaptor... X2 magnification? It appears to be a mechanical adaptor without a relay or intermediate lens (as used by the mini35) and the image circle cast by a 35mm lens would still be the same, which is to say that it would be impossible to 'escape' the 7.2X magnification.
Unless a 16mm lens is used but from the website, it seems to claim only a x2 magnification for 35mm lenses.
someone please clarify.

Adrian

Chris Hurd · June 13th, 2003, 04:27 PM

I'll encourage Barrett to register here and post a reply about how his adapters work.

Kevin Burnfield · June 13th, 2003, 09:46 PM

Please do, Chris. I've seen his stuff on eBay and have wondered about it and it would be great to have him answer questions.

Elmar Tewes · June 14th, 2003, 11:30 AM

there is also a pl mount - xl-1 adapter which also has 2x magnification. and there are some sample shots that where very impressive, very good deep of field. thats possible with such a adapter ? i thought you need a special optical system like the mini35 to get sucha deep of field

Chris Hurd · June 20th, 2003, 08:34 PM

Photos are now on the Watchdog under What's New. We should have the manufacturer posting here within a day or two.

Andre De Clercq · June 24th, 2003, 09:59 AM

I think Charles is correct Jeff...only focal plane manipulation is involved (and can sometimes be of interest for getting some zone out of focus) but is not a DOF adjusting system. Shift and tilt (scheimpfug adjust) is very well known in electronic projection systems too and is being used for focal plane correction if the image plane isn't ortogonal or symmetrical w.r.t. the systems optical axis

May 23rd, 2003, 10:56 PM	#196
Jeff Donald Warden Join Date: Mar 2002 Location: Clearwater, FL Posts: 8,287	It's pretty well acknowledged that EOS EF lenses are sharper. More goes into sharpness than resolution. EOS EF lenses don't have to be 7.2X (difference in chip sizes) sharper. Resolution is target size independent. I have the XL EF adapter and frequently use many of my EOS lenses on the XL1. The difference is very noticeable to me. If you search the topic you'll find that I'm not alone in my opinion. __________________ Jeff Donald Carpe Diem Search DVinfo.net for quick answers \| Where to Buy? From the best in the business: DVinfo.net sponsors

May 24th, 2003, 01:55 AM	#197
Charles Papert Wrangler Join Date: Jan 2002 Location: Los Angeles, CA Posts: 6,810	Hmm errr hmm... Jeff, I haven't used the Canon EOS setup but I am pretty sure I understand what it does in terms of utilizing the center section of the lens to fill the DV target, please correct me if I am wrong. If this is the case, the swing and tilt effect would be very greatly MINIMIZED for a DV setup. I used a 35mm setup on a 16mm camera a few times and found I had to rack the tilt all the way and shoot wide open to get any real effect, and it was much less than if it had been on a 35mm camera. If you think about it, the further from the center, the further out of focus you can get, so if you are only using the center... Do you think it might be more accurate to describe this effect in terms of manipulating the plane of focus rather than the depth of field...? __________________ Charles Papert www.charlespapert.com

May 24th, 2003, 07:06 AM	#198
Jeff Donald Warden Join Date: Mar 2002 Location: Clearwater, FL Posts: 8,287	The way a tilt or shift lens works (any large format lens) is with excess coverage of the target area (CCD chip). What is excess coverage? Imagine your target area (24mm X 36mm film, 1/3 inch chip etc.) and then draw a circle much larger than the target. A typical 35mm T/S lens will have 10mm to 14mm extra coverage on the top, bottom and both sides. The coverage area would be much larger than a 1/3 inch chip (4.8mm X 3.6mm). The image circle of the Canon EOS EF 24mm T/S is 58.6mm dia. The image can be shifted (not tilted) up, down and side to side. The shift mechanism is used to control perspective, i.e. make parallel lines parallel.. The tilt mechanism is used to control DOF. This is accomplished by the tilt controls (on the EOS lens, knobs are rotated). By following the Scheimpflug Principal DOF, can be controlled.. Rather than restate the principal, those interested should download this PDF from the Arri site. The title of the document is Tilt Focus and deals with the principals involved here. It is a 256k document and you'll need Adobe Acrobat Reader. Most of the article talks about tilt (extending DOF). Well, small chip DV users have plenty of DOF and what we're interested in is Swing. A current trend is to call Swing, Negative Tilt. They mean the same. On page 15 are diagrams of no tilt and tilt. On page 16 is a diagram of negative tilt, or swing. The DOF is actually decreased, not just moved or shifted from side to side. Yes, it is greater on one side than the other. Charles, your question is basically my question. Would the greater amount of excess coverage help reduce the extreme DOF on smaller formats? Your experience with it on 16mm would seem to indicate that it wouldn't be enough control. Do you recall what focal length lens you used? The principal works. I made extensive use of it on my view cameras. So, the question remains, how effective are T/S lenses on DV? __________________ Jeff Donald Carpe Diem Search DVinfo.net for quick answers \| Where to Buy? From the best in the business: DVinfo.net sponsors

June 5th, 2003, 10:45 AM	#200
Corey Doyle New Boot Join Date: Jan 2003 Location: New Braunfels, Texas Posts: 6	Xl1s to Canon EF mount (only 2x magnification)?? I saw this on eBay: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2933116229&category=undefined I would love to buy it because I've always wanted the option of using different lenses but I've never heard of this, I thought only Canon made an adapter. And it claims that the adapter only magnifies the image by 2x! Has anyone here used it? One more thing: I'm assuming if I bought this and used Canon EF lenses, it would produce a higher quality image than just using the 16x lens that came with the xl1s. Am I right? Thanks! Corey

June 5th, 2003, 04:48 PM	#201
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,368 Images: 513	This adapter comes from Barrett Bilotta at XL1 Soultions. His products were showcased in the Canon booth at NAB. He's sending us a unit for review; you'll see more about this on the Watchdog pretty soon. Don't want to buy through Ebay? He sells direct. And he gets an endorsement from DV Info. __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

May 24th, 2003, 10:56 AM	#199
Joseph George Permanently Banned Join Date: Mar 2003 Location: Los Angeles, California Posts: 265	Isn't there an EOS lens w/F1.0? I think that there is a 50 mm? one. It will be an extreme telephoto on the camcorder, but would have shallow enough DOF for nice film look; but would probably be limited to outdoors work.

June 9th, 2003, 04:00 AM	#202
Dan Locke-Wheaton Tourist Join Date: Jun 2003 Location: Birmingham Posts: 1	Using EF adaptor, Canon Lens and shake I am looking to purchase a XL1s and I am just researching the different abilities of the camera, so I apologise for my ignorance. I have obviously read about the abilities of the camera to shoot using Canon EF Lenses. My questions are: 1"Can you use these lenses for filming or are they only usefull for taking digital stills with the camera. 2"If you can use these lenses for filming is there a problem with image shake like you get when you zoom out fully on basic set-ups" 3" If they can only be used for stills what is the quality like and what options do you have. Thanks, Dan __________________ Dan Locke-Wheaton

June 9th, 2003, 06:23 AM	#203
Adrian Douglas Trustee Join Date: Oct 2001 Location: Chigasaki, Japan. Posts: 1,660	Dan, You can use the EF lenses/adaptor for regular shooting. However, there is a multiplication factor of 7.2 which means a 100mm lens becomes a 720mm etc. This is great if you are shooting wildlife or surfing but can be a problem if you want to uses them in regular shooting situations. Quality wise I borrowed an adapter from a friend and tried it with my 70-200/2.8L. I shot some surf footage and was totally stoked with the results. The shots were noticabley sharper than the 16x XL lens and at 500-1440 the focal length was awesome. Image shake wasn't a problem but a good tripod and fluid head are a must. Many people here shoot wildlife with the EF lenses and swear by the 100-400 and a few the 35-350. None are by any means "cheap" alternatives especially once you include the cost of the adapter. The bottom line is if you need extreme focal lengths then you can't go past the EF lenses and adapter. If you just want sharper glass for regular shooting then consider the 16x manual servo lens. __________________ Adrian DVInfo.net Search for quick answers Where to buy? From the best in the business...DVInfo.net sponsors

June 12th, 2003, 06:38 PM	#204
Steve Siegel Major Player Join Date: Nov 2001 Location: Albuquerque, New Mexico, USA Posts: 840	Using EF zoom lenses you will get shake even with the best tripod and head in a breeze over 10 mph. Lightly touching the camcorder will do the same. You may not even notice the shake in the viewfinder, but it's enough to be noticable at home on TV. It's just a function of the 7.2 magnification factor. The lenses are superb, however, and well worth the minor inconvenience.

June 13th, 2003, 04:26 PM	#205
Adrian Seah Regular Crew Join Date: Jul 2002 Location: London, England Posts: 87	I somehow find it hard to believe the claims on the adaptor... X2 magnification? It appears to be a mechanical adaptor without a relay or intermediate lens (as used by the mini35) and the image circle cast by a 35mm lens would still be the same, which is to say that it would be impossible to 'escape' the 7.2X magnification. Unless a 16mm lens is used but from the website, it seems to claim only a x2 magnification for 35mm lenses. someone please clarify. Adrian

June 13th, 2003, 04:27 PM	#206
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,368 Images: 513	I'll encourage Barrett to register here and post a reply about how his adapters work. __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

June 13th, 2003, 09:46 PM	#207
Kevin Burnfield Major Player Join Date: Dec 2002 Location: Princeton, NJ Posts: 363	Please do, Chris. I've seen his stuff on eBay and have wondered about it and it would be great to have him answer questions.

June 14th, 2003, 11:30 AM	#208
Elmar Tewes Regular Crew Join Date: Oct 2001 Location: Frankfurt Germany Posts: 104	there is also a pl mount - xl-1 adapter which also has 2x magnification. and there are some sample shots that where very impressive, very good deep of field. thats possible with such a adapter ? i thought you need a special optical system like the mini35 to get sucha deep of field

June 20th, 2003, 08:34 PM	#209
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,368 Images: 513	Photos are now on the Watchdog under What's New. We should have the manufacturer posting here within a day or two. __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

June 24th, 2003, 09:59 AM	#210
Andre De Clercq Major Player Join Date: Sep 2002 Location: Belgium Posts: 804	I think Charles is correct Jeff...only focal plane manipulation is involved (and can sometimes be of interest for getting some zone out of focus) but is not a DOF adjusting system. Shift and tilt (scheimpfug adjust) is very well known in electronic projection systems too and is being used for focal plane correction if the image plane isn't ortogonal or symmetrical w.r.t. the systems optical axis