16x lens breathing

[Tony Davies-Patrick]

I like the 16X lens, and I got it extremely cheaply as part of a deal along with a body, etc. It doesn't have to exibit the same outstanding quality of my expensive Nikkor ED-IF lenses, but then again, it doesn't need to. The Nikkors are made to extract every ounce of sharpness from 35mm film, and they are more than enough for the Canon 3 CCDs.
The 16X manual is not quite in the same league as a fixed Nikkor 300mm F/2.8ED-IF prime, but there again, stuck on an XL1/s/2 camera, it doesn't need to be...you're not going to see much difference - once you view the moving images on a screen - between an XL2 + 16 X lens, or an XL2 fitted with a lens costing ten times as much.

As for the breathing, if I could afford a lens costing $15,000 that fits the Canon (without any increased X factor) and doesn't breath, I'd already have one. At the moment, the 16X manual lens is the very best that I can use for professional quality results.

[Jeff Miller]

Matt -
I don't know how much of the prior thread you caught but I'll again mention my stupid trick of using the backfocus for pulls. You can do very dramatic stuff, it will not breath, and it's repeatable. Try using the macro button, if that doesn't work you will need to loosen the ring and lose your BF setting.

There was flack I got last time for mentioning this; There is a school that thinks backfocus is a sterile clean-room setting not to be toyed with in the field; There is second school that thinks backfocus is just another setting to be mastered, not avoided.

You make the call! :} If you want an example let me know and I'll try to do one.

[Andrew Petrie]

Jeff, I'd be interested in seeing something. Learning different techniques is always a good thing.

[Marty Hudzik]

I'd like to see an example also or at least an in depth description of what you are doing so that I can try it. I would guess if you are using the macro button to focus for this then a focus puller would be out of the question???

[Jeff Miller]

I set up a test and shot some video of the focus trick last night. I'll get some stills of that tommarrow night hopefully and post them if someone doesn't beat me to it. Later!1

[Andrew Petrie]

awesome jeff, can't wait :D

[Jeff Miller]

Here are stills of some video I shot the other night. A quick disclaimer, I am not a pro videographer, photographer, or any other grapher, so don't waste time razzing me if there's something with the pics or if what I did is fundamentally wrong. This stuff makes sense to me and I'm all I've got to work with.
Also, I do believe that the backfocus setting is a somewhat sacred thing, but I also believe that if you need to lose it to get a good shot, then do it.

That said, I hope you like toy dinosaurs.

Setup:
XL2 NTSC, 16x manual lens, 16x9, 60i, 0dB gain, iris at 6 (iirc), CP1: slightly lowered sharpness, slightly upped color gain
JVC 9" studio monitor
Monfrotto sticks, 200w of tracklight
Pics were not worked on in post.

What I did was put two dinosaur toys on stands about four feet apart, and the nearest toy was about six feet from the lens. (In hindsight the toys should've been further apart, but it's how my tracklighting was setup and the example still works). It looked a bit like this:
http://i4.photobucket.com/albums/y12...nfo/setup1.jpg

Our subjects today are a t-rex model and an 'Extreme Dinosaur' action figure (or doll if you want to nut me about it). We begin with a pull on the front focus between our toothy friends. The easy way to view this is to save the files to disk, I open them in Gimp, overlap the windows and alt-tab between them. The files are named by f/b front/backfocus, and ext/rex on who's in focus.
http://i4.photobucket.com/albums/y12...o/ff_ext_1.jpg
http://i4.photobucket.com/albums/y12...o/ff_rex_1.jpg
Well, they focus up nicely and there is a bit of DOF there but it's obvious that the picture changed, look at how the curtain in the lower right moves, and how the figure's arm is in/visible.

Now, I pressed the macro button and spun the back ring to focus up on the rex.
http://i4.photobucket.com/albums/y12...o/bf_rex_1.jpg
then, turned it until the Macro button locked.
http://i4.photobucket.com/albums/y12...o/bf_ext_1.jpg
Neat huh? The background hardly changed, but the subjects go in/out of focus at will. I admit the figure might not completely be in focus because the macro button locked, but I did it that way because it proves that:
1) My silly idea works
2) It works without having to sully the backfocus setting (since I only used Macro)

Granted, the macro trick probably won't work if your subjects are very far away. But, still, there it is.
Also Marty asked me if a puller could do this. I'm assuming we mean like a cable actuated, geared puller. I've never set one up but I'm pretty sure the backfocus ring doesn't lend itself to this. The FF and zoom rings are geared, the backfocus is pretty utilitarian and isn't even very round (the macro and lock all jut out of it). Someone would need they're hands up in the camera for this trick.

Let me know if this is and the images are helpful at all, as I've never posted a test like this before. Thanks, good night. I'm Jeff Miller, and I'm for hire. lmao

edit: added vbcode

[Matthew Cherry]

I just got the 16X lens and this was the first thing I tried. It works great!! Takes a bit of practice to hit the mark, but produces a very nice rack focus.

Matt

[Marty Hudzik]

Matt,
JUst curious on your opinion of the 16x "breathing". To me it is not a big deal so I am curious what you think now that you have it in hand.

THanks!

[Matthew Cherry]

This thing breathes like cheerleader on prom night. I REALLY like the lens for the softer more film like image quality it produces, but a rack focus is definitely noticeable. However I can use Jeff's method to produce some really nice results.

[Marty Hudzik]

Well I agree to some extent except that I often see this happen even in major motion pictures. Depending on the scenario it can actually make a rack focus even more dramatic. However I can see how it would be a problem also.

What do you mean when you say you likes its softer more film like image? I find it to be uber sharp and many others have reported the same, some even claiming that it is sharper than the 20x. I love the lens but I don't feel it is less sharp than the 20x. However slap a .7x WA adapter on this badboy and you'll find it's optical properties start to get closer to a 35mm lens, as far as DOF goes.

[Matthew Cherry]

Oh absoulutlely. I've had the opportunity to recently play with some better lenses and they breathed as well, but not as much, however they were also much more expensive. Plus if you really are just worried about doing a rack focus, the macro trick really does work, I just have to see if I can do it without the camera moving.

Maybe softer is the wrong term. The images are certainly sharp and clear, and just as crisp as the 20X, however they have a softer feel to them - to me. More film like if you will. Film is sharp but not like video, the latitude/colors are somehow different. It's like there is a softness within the sharpness, does that make any sense? It's not a huge difference, and I do like the 20X lens, but the 16X just seems different to me. Maybe it's the lack of Flourite?

Do tell about the .7 WA adapter and DOF. What are you experiencing. Could you use that adapter with a mattebox?

[Mikey Williams]

after reading this thread for a few weeks, I finally rememberd it while i was working the other day. i work at a cbc affiliate news station and checked out their lenses for the amount of breathing during rack focus. I found that even those lenses, beeing close to $30,000 a peice showed some breathing. i have not used the 16x canon lens yet, but it was definatly noticable even on the $30,000 lenses. It must be something that just happens to be common on full manual lenses. Just work with it and if you can disguise it anyway then you know you are doing a good job.