Apart from the usual shallow DOF reasons.

Distant subjects in SD have a distinct lack of detail at 720x480 even with a wide depth of field. Camera-sharpened low-res images really give away the fact that it was not shot on film. Subjects in the foreground in SD don't look so bad, but the background needs a bit of softening to eliminate the evidence of low resolution. I don't think this is quite as important for HD, but the other reasons like drawing attention to the in-focus subject still apply.

Okay, I realize that I'm probably not the first to have this idea, but I haven't seen it mentioned.

Good point. I thought that the greater definition of HD wouild make the focus point more unique and hence standout??
Barry ought to go over this.

I'm not following you here.... If you put a 35mm adaptor in front of your DV camera's built-in lens you are still limited by the quality of that lens, regardless of how good a lens you put on the adaptor. Now with a camera that has a removable lens your point might be more valid.

The current issue of DV magazine has a review of the P&S mini 35 adaptor and they test it on several different cameras. The raise this issue of image quality on fixed vs removable lens camcorders. A chain can only be as strong as its weakest link.

Or maybe I'm just not understanding your point?

An HD (HDV) camera has its own lens capable to resolve the hi def resolution of the CCD/CMOS! (every 3Mpixel and up still digital camera meets and exceeds this requirement) The quality of an SLR lens could be in question (if need be....) but the more "burning issue" with these image converters is:

how thick the GG (diffuser) is ? (the closer to film thickness or thinner, the sharper the image) for a "static" (wax, etc) due to “circle of diffusion” which translates into sharpness or...

how thick and how plane the movement is (if moving "GG") (how well squared to the SLR lens and the camcorder!!!( a very precise mounting to line them up will help a lot)

If those two, three questions can be addressed, then we can worry about the quality of SLR lenses and the camcorder's own lens (imo)

But the point, for DV, is that the CCD/imager is the weak link. Video puts low-res into perfect focus. Further, the internal circuitry "sharpens" the image by adding definition around contrasting details. This is fine for objects in the image that have sufficient detail to be clearly recognizable, but things in the background that are low-res but in perfect focus will look bad since they have too few pixels devoted to them. If you blur partially extraneous background details with the lens, the lack of resolution in the CCD will be less obvious.

What I'm getting at is that it is better to reduce detail with controlled focus/defocus than it is to reduce detail by having insufficient pixels. One says "video" and the other says "cinematography".

I'm just trying to quantify what I, and apparently others, FEEL when we look at images gathered with a video camera with a 35mm adapter.

the internal circuitry "sharpens" the image by adding definition around contrasting details
That circuit only "kicks in" between hi contrasting surfaces. Pretty much everything is too much (on a sunny day) for the narrow dynamic range of the CCD. But try this: close down the iris (camcorder on kicks) while watching some details on infinity. Observe the result on a big screen (30"?)

When the details get down to the artificial sharpness level-(one row of pixels?) (and the hi contrast is there) the effective resolution is slashed in HALF! (that is why, a while ago I suggested the resolution chart be printed on gray instead of white! to "bypass" the "smart circuit" before it does any damage to the image!!!) As for the real advantage (imo) of using an image converter is the GG itself.
It lowers the contrast bringing the real life high contrast image into a more manageable range so the CCD can handle it.

Sorry for those that know this stuff, but here are two pics in support of the above: one the camcorder itself, the other one through MPIC:
http://dandiaconu.com/gallery/album05/IMGA0486
http://dandiaconu.com/gallery/album05/IMGA0485
Yes, the image IS better through MPIC than by camcorder itself!

I'm glad someone more knowledgeable than I put it that way, Dan. I suspected that the GG acted sort of like an Ultra Contrast filter and brought the contrast ratio down. What I didn't know is that the sharpening of the camera would have a quantifiable effect on reducing resolution. I thought it might just be a human perception that a slightly-blurred video image looked better.

I saw part of a golf tournament being played here in Honolulu today. I noticed that the golf ball is practically ringed with a black outline. Some of this can be attributed to shadow, but I believe much of it is due to the sharpening being applied to make details more discernible. Yes, the ball is easier to see and track, but it looks less like a golf ball.

I think what is a more interesting and poignant question than "how to make video look more like film?" is "why does film not look so bad on TV?". I think reduction of contrast and selective focus are critical to the perceived higher quality. After all, a DVD from film looks much better than a televised game of golf, but they are still being shown on a crappy old NTSC TV.

I think there are other pieces to the puzzle, but I think these are a good start.

Perhaps this should have been posted in the "film look" forum?

"why does film not look so bad on TV?". I think reduction of contrast and selective focus are critical to the perceived higher quality
FILM has a
1. MUCH W I D E R latitude of exposure (up to14 stops!!!!!!!) to begin with, thus retaining details in the shadows and without blooming details in the highlights and
2. FILM does not have the "smart circuit" to "sharpen" the negative (thank heaven)
When you transfer "that" crisp image on tape, most nuances captured are displayed, not much is lost (and certainly nothing added like the frigin white lines a video camera generates)
(Selective focus is just a "bonus")

Dan,

Have you had a chance to test prosumer cameras such as DVX100A, XL-2, etc, in this way for artificial sharpness damage, when these cameras have their "sharpness circuit" settings turned all the way down?

I would be very curious to hear whether the artificial sharpness on one of these cameras is still just as bad, when the camera's setting is turned all the way down.

here are two pics in support of the above: one the camcorder itself, the other one through MPIC:
http://dandiaconu.com/gallery/album05/IMGA0486
http://dandiaconu.com/gallery/album05/IMGA0485
Yes, the image IS better through MPIC than by camcorder itself!

Dan, it really looks better through the adapter. Are you selling it already? How much? The times I looked at the prices, they were always changing.

I'd just like to point out that I'm amazed how much of an effect resolution (sharpness, and not the kind you get by digitally enhancing edges) has on noticeable shallow DOF. Playing around with my a 1/3" sensor at 720p+, backgrounds look blurred out quite a bit more easily than on dv resolution. The smaller (and more) pixels sure give foregrounds more detail, which of course makes any softness in a background much more apparent. This of course would likely be negated if that were played on a low-res tv or a dvd player.

haha, wow dan i just looked at those pictures and thats amazing. is that for real? is it possible the chromatic abberation of the camcorder is canceled out by opposite chromatic abberation in the adapter? is the camcorder abberation from a bad lens or pixelshifting?

Have you had a chance to test prosumer cameras such as DVX100A, XL-2, etc, in this way for artificial sharpness damage, when these cameras have their "sharpness circuit" settings turned all the way down?I did not look for those settings and their effect on the image, but I am sure they do the job well. The gs200 has a "soft skin" (equivalent) which works well.
However, the most noticeable difference I have seen was stopping down the iris. (I usually go down some 5-7 steps?= 2 stops? or so..) "Film does not wash out details" is my guide. The "auto exp" is just a "guide" for consummers not to be followed by professionals. Pump up the fill to match the iris settings for highlights and there you have it. Translate 14 stops into 5 and you WILL get "film look", (for the brotherhood of film making).
Michael, those pics were there for over 9 months now, while some pips here were screaming "Dan, why does the picture look so bad? and why is it soft"........sick of it! Email me and you will get MPIC.

I love MPIC, but is it still 8000 USD*? Cool. Quality comes at a price.

wow dan i just looked at those pictures and thats amazing. is that for real?
Phew...of course not! I am just very good at faking shallow DOF ('n all that) in Photoshop. Prove me wrong. (dam, I'm wrong; I don't even have Photoshop installed). $...t!
There is a small add somwhere: prices will change without notice (dam, this IS a notice!)

Michael, those pics were there for over 9 months now, while some pips here were screaming "Dan, why does the picture look so bad? and why is it soft"........sick of it! Email me and you will get MPIC.


Dan, I lost you here, or maybe you lost me. You do know I was making a compliment to the image, right?
Also, what you mean by email you and I will get MPIC?

>>>Dan, I lost you here, or maybe you lost me<<< I can't find myself anyway, so... who cares who lost who?
>>>I was making a compliment to the image, right?<<<
Nooooo,... I wouldn't have guessed! (lol). Did you? Maan, if you will ever figure out how much fun I have here...I'm in trouble! Email me!

What I'm getting at is that it is better to reduce detail with controlled focus/defocus than it is to reduce detail by having insufficient pixels. One says "video" and the other says "cinematography".

I'm just trying to quantify what I, and apparently others, FEEL when we look at images gathered with a video camera with a 35mm adapter.

I just re-read this thread and I have to say, Marcus, you hit the nail on the head with this statement.

I also just re-read this thread and it's a interesting discussion. The sharpening of the DV camcorder was a big reason for me to make my 'double camera'.
In short: A 35mm adapter on which two camcorders film the GG.
Both camcorders are placed on their sides, one shoots the right part of the GG, the other one the left part, with a little overlap. The footage is put back in one piece on After effects.

The reason I write this is because with just two consumer camcorders I got the sharpening effect reduced 2x and it is very much worth it. It's really one of the most noticeable side effects of video.
I'm making a better 'doubleDV 35mm adapter' (or what ever I should call this thing) with a wax screen, so I'll post the results when I get there.

Heh, something interesting I noticed is that War of the Worlds held up beautifully in theaters, but my dvd looks "low res" compared with my Sith DVD. Grainy+deep focus+diffused highlights+blown out highlights does not match up well with NTSC. Artifacting, softness issues, etc. are all present.

The movie is still a blast, though, and beautiful.

Maybe the DVD was just a cheap conversion from a video?

Here's the reason why I believe shallow DOF footage looks better. I don't think it's about sharpening or anything like that. It's the compression that's used. If you've got a scene with a lot of detail in the forground and background, the DV or even HDV compression will be be working quite hard to maintain all that. With Shallow DOF footage there'll probably be at least half as much detail, so not as much compression will be be needed to compress what detail there is there. Meaning the detailed areas will look a lot better. I hope this makes sense?

You can try this yourself just by rendering jpeg images. The file size will always be higher for photos with more detail in them.

The file size will always be higher for photos with more detail in them.
So, you mean to say that between two pics of a resolution chart; one focused at the correct distance for the sharpest image (say 3ft) and another one, this time lens focus at infinity (chart being at the same 3ft), the first one will have a higher data volume? (like 900Kb vs ? ? 600 or so?) (adapter or no adapter)

Ah, we've figured it out! Shoot everything out of focus for less visible compression! Perhaps camera companies everywhere can start using that as a justification for including soft lenses on their cameras.

Easing the burden on the compressor is not the reason 35mm adapters make the image look better, but it is rather a nice side-benefit. Video simply isn't good at making distant details look good. Shallow DOF allows us to keep the foreground in good detail and differentiate it from the background. When detail needs to be seen, we can close in and give the camera a chance. Let's face it...DV, and even HDV sometimes, can't give enough detail with distant objects.

Just like to add that shallow DOF, gives it that "3D" quality, i.e when you have an image that is all in focus it tends to look "flat". However when looking at an image with shallow DOF it seems to give an idea of depth, I guess we relate to it in the way we see the real world with our eyes.

Try this for example grab a pen and bring it close to your eyes (not to close, say about 15-20cm away) and focus on the tip of the pen. Now while your focused on the tip of the pen, can you notice how the background is "out of foucs" ?

Anyway thought I just throw that in !


Anhar

Anhar, that's how I arrived at my idea. We think alike. When you do the near/far focus test with your eyes, think about how long it takes to change focus. I think it is about 1/3 of a second which is probably the best amount of time to change focus during a shoot. I really think that editing and shooting techniques that mimic natural eyeball/brain processes work the best.

As the saying goes, "Video is what the eye sees; film is what the mind sees."

Regarding the time to take to rack focus--I wouldn't recommend putting a stopwatch on such things, there are definitely times where a fast rack is the ticket and other times where a nice slow roll is better. It's totally dependent on the energy of the scene.

One thing I will suggest is that when a foreground element (person, whatever) is exiting the frame and one wants to rack to the background, the best time to start the rack is when the exiting element is about 2/3 of the way out of the shot (i.e., "almost" out). The idea is that by the time they are completely gone the focus has shifted to the background. Often the instinct is to start the rack just as they exit the frame, but then the audience is subjected to an out-of-focus frame that seems to roll into focus late.

So, you mean to say that between two pics of a resolution chart; one focused at the correct distance for the sharpest image (say 3ft) and another one, this time lens focus at infinity (chart being at the same 3ft), the first one will have a higher data volume? (like 900Kb vs ? ? 600 or so?) (adapter or no adapter)

My observation is based on my experience compressing photos for the web. The more detail, the larger the file size needs to be to retain that detail. I've even read an article about it. Since DV and HDV are compressed formats, I'm sure there would be a similar difference. Probably not as noticible of course, as the standard compression usually does a good job in most cases. But I've had DV footage of bushland and areas with plenty of detail. They can look a mess if you examine them up close due to compression artifacts and so on. But a blurred background visible in a shot with a shallow depth of field won't require anywhere near as much compression. So the compression no longer required for the background can then be used to enhance the foreground detail even more. which wouldn't have been possible with the highly detailed background. I hope this makes sense.

Thanks for that tip, Charles. I know I will use it and now I don't have to learn the hard way. I'll bet there is another human process that makes different rack speeds make sense. Perhaps it has something to do with the way the brain shifts attention. Maybe it shifts faster when it is more highly excited?

If there exists some sort of book called something like "The Biology of Cinematography", I would love to get a copy. I would love to know if someone has done a study on why different film techniques work the way they do for human perception.

Glenn, I really hope that you are correct. I know that blurred images take less to compress (there are greater zones of similar color/brightness) in a still image, but will it really leave more room for details in the DV compression format? I would love to know for sure. That would be an excellent side-effect.

Another thing to think about, though, is whats about the worst thing for compression? Grain. There arent many things that dehomogenize (is that a word?) an image on a fine detail level than that. So as soon as a 35mm adapter starts adding grain, it is possible it would significantly worsen the video compressor's ability to be unnoticed. And it doesnt help that the loss of light in such an adapter might cause some of us to turn up digital gain, adding digital noise, even worse for compression than (static) grain.

Charles, thanks for the tip. Those are the kinds of things that can help go a long way toward making amateur or independent or even entry-level pro filmmakers stop making such horrible-to-watch movies.

I use the term movies because "videos" makes the skin crawl, but we aren't shooting "films" around here either. ;-)


Glenn, the real question is:

Is it that a soft background leaves more room for less compression in the rest of the frame... or is it that the DV25 compression algorithms compress everything a given amount, period? For example, a JPEG compressed heavily will show an "artifacty" subject regardless of whether the background is out of focus or not.

Bill,

With DV compression it is both fixed and adaptive. Yes, there are only 25Mbps to work with. How those bits are allocated is part of the compression scheme. If some areas of the image are "simple," then there are more bits left over for those areas that are "complex." Whether you achieve that simplicity through shallow depth of field or through simple set design, the effect is the same: better use of DV compression.

The adaptive quality of it holds true for black and white DV as well. Shooting black and white in-camera will result in a better image than converting to black and white in post. Since the color channels are vastly simplified, nearly all of the bits are used to create a very high-quality black and white image.

As for in-camera sharpening, nearly all cameras do it, most overdo it by default, and it is rare in non-professional cams to have any control over it. My GS400 has a slider in the menu to control sharpness. Simply turning it down results in perceptiblly shallower depth of field, because out of focus objects are allowed to stay out of focus and not sharpened up by the camera. Also simplifies the image, improving the overall quality, per my first point.

I have heard of a lot of video shooters who always use a ProMist filter to "take the edge off" their video. However, the filter is outside the camera, and while it may soften a bit, the camera generally going to defeat that effect by the excessive sharpening that it performs. It's like allowing the camera to fight against itself. A better solution is to find the sharpness or detail setting in the camera and just take it down a notch.

Josh