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-   -   XL1S solutions adapter? (https://www.dvinfo.net/forum/canon-xl1s-xl1-watchdog/32723-xl1s-solutions-adapter.html)

Dragi Vujacic September 29th, 2004 03:45 PM

XL1S solutions adapter?
 
Ok Title says almost everything. I am thinking to buy XL solutions adapter for my CanonXL1S and Canon EF 50mm f/1.8 II lens. What do you think? Can I improve my video and get dept of field shallow? Is it possible to make it on my own or ? I know you've discussed on DOF many thime but it is concrete question. Thank for trying.

Charles Papert September 29th, 2004 04:01 PM

Simply put, this will not make your depth of field shallow, it will only allow you to mount 35mm lenses.

Dragi Vujacic September 29th, 2004 04:22 PM

Thanks
 
Thanks Charles. Maybe it is worth to buy. Still I am wonder - can I make this simple adapter in my homemade version?

Jeff Donald September 29th, 2004 10:51 PM

Unless you shoot wildlife/nature documentaries or do surveillance work, the ability to mount 35mm lenses will have little value to you. Save your money.

Dragi Vujacic September 30th, 2004 03:56 AM

But if?
 
Jef save me money and answer on this. They on XLSolutions clame that it magnify 2-4x - how can it be? Is it 2 or 4 ? Is it enough to shoot in usual locations?
OK, OK I'll listen to you but confirm me one more time please.

Jeff Donald September 30th, 2004 07:19 AM

The adapter was tested by several Wranglers with the same results. Mr. Bilotta has not posted here in over a year. He refused refunds to several members that refuted his claims. It does what all EF adapters do, magnify about 7 times.

Bill Ravens September 30th, 2004 07:26 AM

Jeff...

On this note, I'm afraid sir, you are quite wrong.
I use the XL1 solutions adapter regularly and have photos posted on this very site to prove the mag factor is ~1.5

I have ABSOLUTELY no vested interest in this product other than to make sure there is no BS and incorrect info perpetuated on this forum.

If you've ever shot with one of these adapters, you'd see that what you keep saying is incorrect. Until you've used one, I suggest you defer your opinions.

Charles Papert September 30th, 2004 08:38 AM

Bill, then perhaps you can explain what Barrett would not: how exactly does a mechanical adaptor with no relay lenses (essentially, a step-up ring) achieve this low magnification factor?

Also, please point us to the aforementioned photos.

I would love to be proven wrong about this adaptor. I requested one to test last year. Barrett avoided me.

The magnification factor is a simple thing to prove visually. You line up a 35mm lens on a chart or other verifiable frame (such as a doorjamb that spans the exact width of the frame), then repeat with a standard 1/3" lens and note the focal length that delivers the same field of view. Then multiply that focal length by the appropriate factor (4.4 for cine lenses, 7.2 for still camera lenses) to arrive at a common denominator, as it were. Then divide this number by the 35mm lens focal length to determine the degree of multiplication.

The XL1 Solutions site could easily demonstrate this; instead, no 1/3" focal lengths are shown for the comparison shots. This page, for example, shows an 18mm cine lens compared to a 16x XL1 lens. My thoughts on this test are:

--No focal length is given for the 16x lens, making the magnification factor a mystery
--The image sizes weren't particularly well matched
--The DoF is not significantly different between the two
--My estimation based on the compression seen in the 18mm shot is that it looks to be an equivalent of 50-75mm field of view
--A certain number of people would view the first two shots and be led to believe that the cine lens delivers a "nicer" image; this would have something to do with the 16x version being exposed a good stop hotter and in raw sunlight (the 4th image is at least shaded or silked, but out of focus...)

Bill Ravens September 30th, 2004 09:24 AM

Charles...

Back when this subject was a hot issue, I did almost precisely what you have suggested. Using a ruler, I first captured an image of the ruler with a Canon 16x manual lens mounted on an XL2. Without changing the setup(distance to the target), I then mounted a 85-205 FD zoom lens, via the XL1solutions adapter, to the XL1s. I was as careful as I could possibly be to set the same indicated focal length on both setups, altho' I admit some small error can be attributed to interpolating the lens barrel markings. By comparing the scales on both resulting images, one can calculate a scale factor, which I did and came up with 1.5X.

By the way, I also ran a test on both lenses at the same f/number and focal distance, using the ruler aligned to be receding in the distance. I manually focused on a tick mark in the center of the ruler, with a circle of confusion on either side of the focus point. By studying the range of in-focus tick marks on the ruler, I concluded that the 35mm FD lens gave me a (edit:)"lesser" depth of field. This is explained because, as I understand it, given two lenses of identical configuration, the difference being one lens has a much larger maximum aperture, the DOF on the large aperture lens will be less than on the smaller aperture lens. Of course, the preceeding is true if the f/numbers are set the same for both lenses.

I've removed the images I had posted on my website months ago. Time permitting, I can reproduce my tests and report back. At the time, Don Berube and I communicated on the results and I sent him copies of the images.

In my brief communications with Barrett, he was quite insulted with the treatment he received from several members of this forum. I concur that his treatment was discourteous. It's no wonder he hasn't returned, however, I don't know him well enough to claim to speak for him. I'm sure, if you did a forum search for XL1Solutions, you'd find my old postings.

I recognize that you have technical questions about how this was achieved. I'm not an optical physicist, but, a mechanical engineer. If you want physics to explain how this works, I'm the wrong person to ask, sorry. All I can do here is report my experience and the rest is up to the beleivers and non-beleivers.

best regards

Dragi Vujacic September 30th, 2004 11:33 AM

Plan
 
Ok. That’s what I am going to do. I’ll just buy lens EF 50 - f/ 1.8 and since this adapter has no glass of any kind I will experiment with distance betveen camcorder and lens and find is it worth buying anythig else
Lens is good anyhow. Thanks for good advices.

Chris Hurd October 10th, 2004 11:25 PM

If you feel like it, Bill, you could email those images to me and I'll be happy to host 'em.

Charles Papert October 11th, 2004 09:56 PM

Bill, what you described is not a comparison that I believe I suggested, since focal length is focal length regardless of what camera it is mounted on. What we are interested in is field of view for a given focal length.

Here's an experiment that should illustrate this.Shoot your ruler with the camera lens mounted to a still camera. Now, mount that same lens to your XL1 via the adaptor and place it exactly the same distance to the ruler (remember to measure this from the film plane/image sensor). Now what is the magnification factor? Nominally, it should be 7.2x.

I went to the bother to review this thread. Discourteous is not what I would call the treatment Barrett received. Several people asked pointed and specific questions, and many of the answers were supported not by explanations (i.e. why is this adaptor able to do what others cannot?) but by citing his customer base. The website is similarly unclear.

The issue that I had was that readers of DVi could be mislead into thinking that this adaptor will allow them to achieve the equivalent depth of field at a given field of view as one experiences with cine or still cameras, or even close to it. There are many out there who are desperate to achieve shallow focus for a low price (almost fanatical, really). The Mini35 is the only practical commercial item that achieves this that I know of (the Movietube is still vaporware in the US).

I felt that Barrett was not particularly clear in his claims for his product. I privately emailed him to ask to demo his adaptor; he responded to one email but not to the next (all of which was respectfully and courteously voiced). It was certainly his choice to send me a unit or not.

Once I saw Don Berube's sample images which clearly showed the magnification I would have expected, I proceeded to post my assessment of the system. Barrett had every opportunity to refute or counter my assessment; several times I asked to be proven wrong. He chose not to respond, so I stuck with my assessment.

I have no ax to grind with Barrett or his company. I do feel inclined to keep our members from being misled, if possible.

Bill Ravens October 12th, 2004 07:30 AM

Charles....

I've done a little research of my own on this subject, since, there seems to be much disagreement. I have been guilty of perpetrating a little mis-information myself, mostly from making the right observation, but, drawing the wrong conclusion.

The DOF issue with this adapter appears to be real, however, I don't beleive it's related to the adapter itself, nor to the fact that a 35mm formated lens has more DOF than a 1/3 inch lens. The facts are that ANY lens of the same focal length and f/number has the same DOF.

Actually, it's not a DOF issue at all, but, rather, an issue with lens quality and pixel size. There "appears" to be less depth of field with the adapter and 35mm lenses because of the interplay of lens resolution and the resolution limits of the sensor used on the XL1. A blurry image is a blurry image, whether it's related to DOF or overall system resolution. This scenario is peculiar to pixelated sensors, and not experienced with film, because the "grain" size of a sensor is so much larger than on film. A lens designer, particularly if he/she is subject to corporate pressure to keep the cost of the lens low, has no need to design an expensive lens with resolution greater than the resolving power of the sensor. So, what appears to be lower DOF is, in fact, lower overall lens resolving power....aka...a cheap lens.

As for magnification factor, I think you're wrapping yourself up in some semantics. Your description of how a 35mm lens functions on a smaller film plane format is correct. Nevertheless, when you blow up both images to a fixed viewing size, like 720x480, you see some "apparent" magnification. Of course, this type of blowing up of the image always produces blurrier images.

At any rate, I continue to use my XL1Solutions adapter. The images I capture with it and my Canon FD lenses are useful to me. Itwould be of interest to repeat my tests with my XL2, since I beleive the XL2 sensor has smaller pixels than the XL1s.

As for everyone's feelings, including Barrett's....it's water under the bridge. There's enough ill will in this world without me harping on something as trivial as emotions.

Dragi Vujacic October 12th, 2004 01:19 PM

Ok, since I've started this theme - little responsibility won't hurt.
I think, it has nothing to do with adapter. Since it has no it’s own lenses it do nothing but keep the attached lenses firm and on appropriate distance. Which means - on focal distance where back-lens drop the sharpest picture. This picture is huge about 35 mm (for 35 film lenses) and it depends on the size of the sensors inside how big part of that picture it going to receive. The smaller the chip, the bigger magnification is (smaller amount of 35mm picture drops on it), so else is mathematic or Mini 35 or in the best case Kinetta. So to conclude- no-one adapter with no glass prism (lens) inside can’t make less magnification. Thank you lads.
By the way - what you think about Kinetta?


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