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-   -   Wide shots and DV (https://www.dvinfo.net/forum/open-dv-discussion/3862-wide-shots-dv.html)

Aaron Koolen September 23rd, 2002 09:24 PM

Wide shots and DV
 
Hi all, been hearing people say around the place that you should avoid wide shots in DV because of the low resolution making them come out bad. Any one had any experience with this, and maybe have some example wideshots of landscapes or something?

Barry Goyette September 23rd, 2002 10:43 PM

Here are some thoughts on this.

Realistically , the limiting factor which causes the "wide shot fuzzy's" is the resolution of the format, which at 720x480 doesn't allow for much in the way of fine detail, so the farther you get from the subject the less sharp things start to look. This happens to some extent with all formats including 35mm film, its just more noticeable with dv.

DV (specifically canon xl1, gl1) is capable of acceptable "wide" shots, but care needs to be taken to maximize the resolving power of your system ie..avoiding frame mode , and keeping your fstop in the f4-f8 range. You may find that kicking up the sharpness may help a little, or you might find it just makes matters worse. I think the gl2 does a fine job at wider shots, even at lower apertures and in frame mode, due to it's higher resolution chips.

For what it's worth. I just got the 3x and 16x manual lenses for the xl1s. Overall, I don't see a big difference improvement compared to the stock lens, but they do seem to be a hair sharper at the wide end.

Barry

Josh Bass September 24th, 2002 12:19 AM

Let's say you'd shot the majority of whatever it was in frame mode, and did your wide shots in 60i. Is there way (hopefully cheap) to de-interlace in post? Some sort of free download or plug-in. Using Vegas Video, by the way.

Daniel Chan September 24th, 2002 01:39 AM

Wide looks good to me...
 
I recently shot some beach footage with the XL1S and the 3x wide angle lens, and I have to say I am amazed at the quality of my footage.

It was a bright sunny day and it was about 2:30 when I shot the footage. The textures of the sand is very clean and I see a lot of detail, there is also some hills full of deep green trees and under the harsh sunlight the footage shows a lot of color and very well defined detail in them.

I haven't heard anything about losing detail with DV...

I had a polarizer on along with the ND on. I was shooting at about 1/100 and 1/150 shutter and the on f2.8, 3.2 the truth is I didn't really have a plan on how to shoot this, I just adjusted the settings as I went and judged the look through the view finder, it could well be luck.

I upped the color and color gain, 2+ on sharpness, I think the fast shutter speed helps add sharpness. it looks very crisp, better than say 1/50. try it out under bright sunlight and the high shutter.

try it out.

Daniel

Jeff Donald September 24th, 2002 05:57 AM

You may be referring to one of my recent posts about comparing mini DV to Betacam SP. Betacam heads use either 2/3 or 1/2 inch chips. They provide more detail (noticeable in wide shots) and control contrast better (more detail in shadows and highlights). The difference is not all due to the chips. Some of it is related to the compression (DV is 5:1), color space used (4:2:2 vs. 4:1:1) and the signal (DV is 8bit and newer Betacams are 10bit or higher).

But DV has its advantages too. One thing that is not pointed out here, is that video is sharper than film close-up. I have a friend who shoots wildlife with 16mm and sometimes 35mm. We'll go out together and shoot the same subject. His establishing shots look sharper than the video shots I take. However, when we do close-ups of birds the video wins. My shots will have more detail than his. Digital is a close-up medium. Us it to your advantage.

Jeff

Barry Goyette September 24th, 2002 10:49 AM

Josh

I don't know of any free "smart" deinterlacers. I have used revision effects RSFieldskit, and found it to work well...don't know if it works with vegas..its an aftereffects plugin that also works in FCP. I costs about a hundred bucks.

Barry

Josh Bass September 24th, 2002 11:33 AM

That makes me say to myself, do I really want a wide angle lens now? Why do I need to be so wide? Do I love pixels, and want them to manifest themselves in all their pixelly glory?

Barry Goyette September 24th, 2002 12:19 PM

Josh

Don't get confused between a wide angle lens and a "wide shot". To quote myself from a previous thread-----
----------

.....I think your point is a good one. Although I don't think the problem you described is specific to use of a wide angle lens as it is to lens-to-subject distance or more correctly "amount of subject in field of view". Using a wide angle lens to make close-up of a frosty can of Diet Coke will produce a very sharp image, while using a "normal" length to shoot the crowd and field at the superbowl would produce a fuzzy mess. (this effect can be seen on just about any film or video format...it's just more noticeable on the dv format because it's resolution is lower)---

--------------------------

A wide angle lens can produce some very dramatic and sharp results, especially if there is important detail or subject matter in the foreground. I use a wd-58 adapter on the gl1 and 2 all the time and love the results. I just got the 3x lens for the xl1s and the image is perfectly sharp especially when there is someone relatively close to the lens.

I come from a still photography background, and although I don't shoot alot of landscapes, when I view other photographers work of a wide vista type, I walk up close to the print, somehow hoping to see pristine detail in each and every cactus...I am usually disappointed, as the detail doesn't match what a close-up view would, even if it was shot an a 4x5 camera. This effect gets worse as the film format gets smaller...ending with DV. But the issue is not really the angle of view of the lens, but rather the inherent resolution of the image plane in combination with the amount of stuff (and the size of that stuff) in the image plane.

Barry

Jay Gladwell September 24th, 2002 12:32 PM

Josh, go to http://www.dvfilm.com/maker/index.htm and read what they have to say about DVFilm Maker. It's only $95! The guy who came up with this explained it all to me--went right over my head.

You can download a demo version and give it a try. It works regardless of the editing software you're using.

Josh Bass September 25th, 2002 03:33 AM

To Barry: I understand all that. But the reason I would want a wide lens is to get nice wide shots in rooms, and of course some exteriors, as well as everything else. But the wider the shot, the fewer pixels there are to represent everything in it, and therefore the fuzzier and nastier it will be.

If a wide angle lens can increase the perception of depth in the picture, though, that's good. I didn't know that.

Is it still possible to get shallow depth of field with a wide angle lens, or rather, a wide angle converter on the 16x lens?

Jay Gladwell September 25th, 2002 05:20 AM

Attempting to get a shallow depth of field with a wide angle lens would be, perhaps, akin to waterproofing the exterior of a submarine.

You can achieve it. In over thirty years of shooting images (still and motion) I've done it once. It was a challenge to say the least.

Andre De Clercq September 25th, 2002 07:17 AM

Getting a given depth of field with a wide angle lens is just as easy/difficult as getting it with a zoomed in lens and back of to keep the same object dimensions. Only the F-number and the target(CCD)dimensions determine the DOF. Given the fact that a zoomed-in lens generally has a higher F number than when zoomed out, the DOF can even be shallower in wide mode (and getting close to the object), if other constraints allow close setting

Jeff Donald September 25th, 2002 07:33 AM

There are more factors than F number and target dimensions. Actually F number is not part of DoF, but diaphragm opening (effective aperture, not F number) is part of the formula for determining DoF. This thread http://www.dvinfo.net/conf/showthread.php?s=&postid=21371 may help in determining depth of field. At the end of the thread is the formulas for determining DoF. Focal length of the lens is part of the formula. If all other factors remain constant, a shorter focal length lens increases DoF.

Jeff

Andre De Clercq September 25th, 2002 08:17 AM

Sorry Jeff, a couple of things are not correct in your reasoning. There are no more factors involved in the DOF story than what I mentioned. (appart from the "circle of confusion" which I left out for simplicity reasons) First, if one takes the absolute aperture value, one has also to divide by the focal length in the DOF expression. The ratio which you then get is exactly the F number (Fnumber=aperture diameter/focal length). That's why the F number is allways used. Second, I don't see where you get your conclusion out of those (simplified) DOF expressions. Image size isn't even mentioned. If you want somewhat better info and insights, I invite you to look at the expressions here http://www.dof.pcraft.com/dof.cgi, and if the math confuses you, just play with that DOF plotter. Let me know if you then still remain convinced about what you pretend. You can allways give it a real live test...and see what the results are...

Barry Goyette September 25th, 2002 08:43 AM

Josh

Despite the mathematical discourse above, in practice, you will find it difficult, ne impossible, to achieve anything near "shallow" in terms of depth of field with a wide angle lens on the xl1s. If you put something close (5-10 inches) to the lens, can you make the background go out of focus....? Yes, A little, but as I test this right now with my camera, I don't think anyone would call the DoF shallow. That, to me, would imply that nearby objects would also be out of focus, and even wide open, that ain't happening.

Barry


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