does the 30 fps video effect (not frame mode) reduce resolution on the xl-1? I would rather use this to get a bit more light.

You know, some people say this is true, but I think that this is really exaggerated. It might be the case that some of the pixels on the CCD don't get used for some of the frames, but it's still a 720 x 480 picture and probably indistinguishable to the naked eye - unlike the 16x9 anamorphic stretch mode, which clearly does compromise significant resolution.

You are not loosing actual pixel resolution, but quality. The camera's
CCD chips & electronics aren't fast enough to actually scan 3
CCD's each frame. So what it does is some form of de-interlacing
with smoothing and such. So you loose quality and sharpness
here (which actually can be seen). Some people prefer it however.

Search (by using this forums search feature) on the words frame
mode and you will find plenty of threads on this subject. There
also was an article out there that explained it much better than
my words in clear pictures, but I don't seem to be able to find
the link to that article at the moment. Perhaps someone else
knows it.

Hope this explained it some

Well then the question is - is the internal frame mode better than using the video editing software to deinterlace the footage?

Actually, my question is whether the frame movie mode better than the 30fps digital effect

Ok now I don't know what you're talking about. Do you mean merely adjusting the exposure setting to 30fps for lower light situations? No that should not affect quality at all. You should have a normal interlaced 60i video that will simply not have as smooth motion as you would with a 1/60 shutter.

no matter how you slice it, the XL1s shoots in interlaced mode, ONLY. Normal mode is standard 60i with one field captured every 1/60 sec. Movie mode is interlaced with 2 fields captured simultaneaously every 1/30 sec.

Frame mode aside, you should have no problem shooting in 30fps in low light. The image will not be degraded. Probably look better than 60fps with gain up. There will be a tendancy for more motion blur but it shouldn't be noticeable unless there is alot of movement in the scene. Even then you might like the look.

Rick

Yes, I believe the question is whether the 1/30 digital shutter speed is better/worse/same than the frame mode.

Personally I use the 1/30 shutter and leave the frame mode off. You get a bit more motion blur (though not too much) with the 1/30 than the Frame Mode so it makes it seem a tiny bit smoother to me.

But the resulting footage is still interlaced, right?

both are still interlaced. the frame mode just has both fields shot more or less at the same time to give the illusion of deinterlacing. for 30fps, though, i'm sure it's interlaced, but i don't know what kind of processing it does that's why i'm concerned about quality. I don't think that little boost of light does not come at a price.

i prefer the 30fps because of the motion blur, but, of course, shoot at a faster shutter if i plan to slow down the video in post]

does anyone know how the 30fps is achieved?

another question is- what is the effect of the 30fps on depth of field?

Shutterspeed doesn't directly affect depth-of-field.

Although when you use a 1/30th shutter, you might need to close down the iris a bit to reduce the amount of light a bit. In THAT case, the depth-of-field increases, meaning a larger image area is in focus.

If you don't want that, you'll need to reduce the amount of light entering the lens by using ND filters and keeping the iris open.

Bar3nd

"both are still interlaced. the frame mode just has both fields shot more or less at the same time to give the illusion of deinterlacing. "

No, frame mode video is not interlaced, at least not when imported into the computer. It is 30 distinct 720 x 480 frames per second which you can treat as film for rotoscoping, etc.

I beg to differ....frame mode is MOST CERTAINLY interlaced. You just can't see the interlacing because there are no temporal distortions.

barend,

I'm asking about depth of field in a situation where available light is compensated while the opening, focal length, distance of subject and background is kept constant to provide the same exposure for both the frame movie mode and 30fps effect

"I beg to differ....frame mode is MOST CERTAINLY interlaced. You just can't see the interlacing because there are no temporal distortions."

Define interlaced then, please. Are you talking about what's output to a TV over S-video (always interlaced) or what's recorded to the computer after video capture? What's recorded to the computer after video capture is progressive footage, 30 fps, each frame of which is distinct, film-like, and can be captured, rotoscoped, etc. You can totally tell the difference between that and truly interlaced footage in Premier - truly interlaced footage not only has the artifacts you described, but also plays interlaced on the screen. Frame mode output does not do that.

DV standard, by definition, is interlaced. It can't be anything else. The reason frame mode doesn't look interlaced is the ingeniousness of Canon tricks with recording two simultaneous fields.

Read the article on Chris' website on how frame mode works...from the horse's mouth

When edited in Adobe Premier, the video is unquestionably non-interlaced. You can capture or rotoscope any one of the 30 frames per second you want and it looks fine. So what is the difference between that and being non-interlaced? The internal format on the DV tape? Who cares about that.

Bill's right, of course, but Peter hit the nail on the head. Canon's hardware interlacing scheme sure makes shooting video for web delivery a lot easier.

Interlaced or non, I output for TV, so it is the frame mode vs 1/30 that concerns me. So, is there a consensus on whether the 30fps effects degrades quality in terms of saturation, contrast, sharpness? Even depth of field? I ask because the 1/8 shutter looks quite muddy to me even when shooting still subjects

Canon's Frame Movie Mode will degrade sharpness regardless of shutter, because it's an interpolation process.

robert, i'm asking about the 1/30 digital effect, not the frame movie mode

Right. So I think the answer is still what I suspected. The 1/30 sec shutter speed is exactly that. It should not affect the quality at all. But the video is still interlaced and would need to be deinterlaced by your editing program if you wanted it to be.

But since you're outputting to TV, which is always interlaced unless you're talking about DVDs and ED- or HDTV, the 1/30 sec shutter, in Normal Mode, should be fine for you. What you'll see are slightly less smooth motions, but there's no reason you should see any image quality loss like you *might* (and I emphasize might because I still don't have 100% faith that frame mode degrades anything) see in frame mode.

Yes frame mode and 1/30 shutter is interlaced, but there are ZERO motion artifacts like there are in standard interlaced video (like that from just about any other video camera that preceded the XL1), so no de-interlacing is required. It's great for frame grabs. Deinterlacing will make your video look a bit more blocky and do nothing for the motion.

Last question, then- camera and subject motion out of the question. Would the 30fps effect have some sort of quality degradation such as the 18db gain?

Nope...in fact 30fps adds smoothness to motion, especially pans.