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?

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

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.

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

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

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

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?

Josh

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

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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

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.

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?

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.

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

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

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...

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

Dre, I have to agree with Jeff. I've never pretended to know, much less understand, all the math and physics that come with photography, especially lenses. However, as I said earlier, I've been making images for over 30 years. The basic fact remains, wide angle lenses have an inherently deeper depth of field than normal or telephoto lenses.

Barry, what you experience is well knowm with those small CCD's. See http://www.mini35.com/ if you realy need DOF that matches 35mm film.

Jay, plse make (once again after all those years..) a test setup like two resolution charts at different distances and compare (for the same scene size) the zoomed-in and the zoomed-out pictures...

Dre, no need to do more "tests." I know what I get and I know what my lenses can and can't do. Looks to me like you're trying to "sell" something. I ain't buying.

In all those "samples" on the mini35 site, there isn't one shot I can't duplicate using the lenses I already own.

Jay, of course you can't duplicate..that Dof adapter is not a "lens" but an image (re)projection concept

You misunderstood what I said. I CAN duplicate the images they show using my exisiting lenses WITHOUT their adapter. I have shot similar images with comparable depth of field on several occasions.

Alright. Didn't mean to start a war. I was just hoping that if I did get a converter, I wouldn't have to take it off. . .like ever.

That's cool though. Thanks for the advice. And play nice.

Sorry, Dre, and Josh, I just get a little riled when I'm told something can't be done and I've been doing it for years. Apologies to all!

I'm simply looking for a solution for all situations. Attach a wide angle converter to the 16x lens and you get the best of both worlds (partial zoom, that is, 10x)

You have to make the choice that's right for ya.

The main hassle with adding a WA adapter to either 16x lens, is that you're making a front-end heavy camera even more front-end heavy.

The advantage of the 3x lens is that it's a lot lighter and easier for hand-holding.

Sorry Jay for my misreading. Only one question, just for my own knowledge, and then I'll stop discussing. Could you plse inform me what the CCD size and the F-number is you use for getting those simualar images? FYI I have been heading lens design for about 25 years, so, maybe I have some background too..

dre. . . . . .

You mention only 2 factors in determining Depth of Field. <<< Only the F-number and the target(CCD)dimensions determine the DOF>>> You need to reread Nicholas Sushkin's Depth of Field Calculation. The thin-lens equation takes into account focal length and distance to the subject. In DoF calculations in this country we usually don't use the term f Number. What is used is the effective aperture (or size of the opening of the diaphragm). It is a size for example 12.5mm, not F2.8. The effective aperture, 12.5mm is divided into the focal length, say 25mm and the relative aperture is F2. The information below is from the post I suggested you read. It is the way depth of field works and it is in agreement with Nicholas V. Sushkin, the author of the DOF plotter you referred to previously.

Depth of Field (DOF) is dependent upon the following variations:
a. The focal length of the lens.

b. The diaphragm opening (effective aperture, not F-number).

c. The distance from the lens to the object that is focused on.

d. The distance from which the image is viewed.

e. The viewer's personal standard of the permissible degree of sharpness (or unsharpness).

Other variables remaining constant, it follows that:

a. The shorter the focal length of the lens, the greater the DOF.

b. The smaller the diaphragm opening, the greater the DOF.

c. The greater the distance to the object being focused on, the greater DOF.

d. The greater the distance from which the image is viewed, the great the "apparent" DOF.


Jeff

Plse instead of going on with pseudo math. Check it and see if you can change DOF if the scene (subject) size remains constant and you zoom in and out, and of course adapt your shooting position to get the constant imag size. I demonstrated it several times to non scientifically skilled people.

Dre, when I want to reduce the depth of field (using the XL1s) I will set the gain at -3db, turn on the neutral density filter (additional NDs may be added if needed) and add a polarizing filter to help intensify color saturation. All this usually gives me an f-stop of between 2.8 and 3.5, depending on the lighting.

Going back to the shots on the mini35 web site. I would just about guarantee than most, if not all, of those were shot with a lens that would fall into the "telephoto" category. For example:

- The man and children feeding the birds
- The railroad yard shot through the fence
- The close-up on the branch panning to the kid on the bicycle
- The shots of the trees
- The fountains

The remaining two or three shots are questionable. But any of the above can be duplicated with the lens on the XL1[s], because I've done it, as I'm sure others have, too.

Telephoto lenses, as you well know, appear to compress the depth of space in images. You can photograph items fairly spred out along an axis perpendicular to the front plane of the lens, and yet when shot with a telephone lens, they "appear" to be closer together than they really are. All the images listed above have that trait.

No reflection on you, but my life's experience has shown that many designer have little appreciation for the vast possibilities for implimentation of the tools they've designed. My point is, the scientific design and the creative application don't always coincide.

I didn't realize my degree in Physics made me non scientifically skilled. I'll ask for my money back.

Jeff

Thanks Jay.