Some questions about a MiniDV cam

[ermi]

Hi,

I found a Sony DCR-PC350E, which I'd use to play around and record some stuff. Eventually, I'd like to produce movie-like videos.

1. I thought that recording in progressive mode is reserved to expensive cameras (yes?), but this one has it as well, as an option. It records to 25p. Is this the real progressive mode or can it somehow be "fake"?

2. I can't select both 16:9 and progressive mode in the camera's menu. Why?
OTOH, I can select the 'cinema effect', which does just that (16:9 and progressive). Is it just a silly limitation or is there more to it?

3. The 16:9 and the 4:3 recordings have the same resolution (720x576) when I capture them to my PC. I've read about it here and elsewhere, so I have a slight idea about what's happening. But still: those two aspect capture a different "portion of the visual field". That is: 16:9 captures more horizontally, but cuts some vertically, while 4:3 captures more vertically, but cuts at the sides. (It's not that it just add black bars or anything like that). Which of the resolutions would you recommend? Which one is more native? (I'm suspecting 4:3 is, because of the 720x576 even for 16:9 recordings) Can 4:3 recordings be stretched to 16:9 (in Vegas...) to produce the same quality video as if I recorded in the 16:9 mode?
BTW, The final product (DVD...) will always be 16:9, because that seems to be the standard now.

4. I want to add a lens for a wider visual field. Like this one, for example. Any other recommendations or tips?
Also, what exactly does 0.7x magnification mean? Does it mean: If now I see 1m of the wall [from a certain distance] with that lens I'll see 1.7m of the wall?

Thanks in advance!

[zoobie]

1)I think 25fps is what it is
2)Probably just the way it's setup for convenient on-the-go shots
3)However you want to finally display it
4)A little cam like that, I wouldn't bother

JMO...looks like fun

[ermi]

4)A little cam like that, I wouldn't bother

Hmm, really?
I do intend to get a new, bigger camera in the future, but I'll probably wait another year or so, to buy one with SSD and HD resolution.

And I'm still trying to figure out how exactly it would work.. the 0.7x magnification.
Let's say I'm standing 100cm away from what I'm recording. With 0.7x lens it will look like I'm standing 100cm x (1/0.7)=> ~142cm away. Is this right?

[ermi]

I have another question... I import my 720x576 video with DAR 16:9 into Vegas. Vegas recognizes it as 16:9 and also there is no need to change the resolution for making a DVD, it's all good.

But to make an XviD .avi it's better to make a resolution with square (1:1) pixels. So for 16:9 it should be 720x405. However, if I use that resolution I get black bars at the top and bottom. I have to use 720x394* to get rid of the black bars. Why is it so?




*I also tried with 395 but Vegas gives me this error on rendering:

It works fine with 394 and 396. What's going on?

[ropdoh]

Some answers:

Your 25p mode probably is true progressive mode. I have a cheapish Canon camcorder which shoots in 25p if desired. Just make the decision if you want to use progressive or interlaced mode. Interlaced works better when you are shooting lots of motion, but you have to deal with the fact that it is interlaced.

Lots of codecs require frame sizes to be multiples of 4, 8, 16 or 32 (which one depends on the codec).
That most likely the reason why a size of 395 is giving you an error.

For the wide angle lens, you don't have to stick with your camcorder brand. Buy a cheap one (unless you are really serious about quality, etc.)

I use one of these:
http://www.amazon.com/SIMA-SLS-05-Wide-Angle-Conversion/dp/B00009K076
Works nicely for the videos I've shot

[edDV]

Hi,
...

1. I thought that recording in progressive mode is reserved to expensive cameras (yes?), but this one has it as well, as an option. It records to 25p. Is this the real progressive mode or can it somehow be "fake"?

Depends on how they do it. Most camcorders of this class can't achieve true 720x576p at full 25fps. They cheat it from a field (half vertical resolution) and/or reduce frame rate.

Video sensor resolution is 2,048,000 square pixel which needs to be divided into RGB and cropped 70% for 16:9. That leaves about 475K pixels per RGB component if RGB filtering was perfect. One monochrome frame of 1024x576 SD PAL 16:9 is 589,824 pixels. Thus video scaling and processing may allow close to adequate resolution for progressive SD 16:9 but RGB filtering will not be perfect and the optics will further reduce effective resolution.

Users report jerky playback in progressive mode. This implies 12.5 fps single field in progressive mode.
http://www.amazon.co.uk/review/product/B0002K78NK/ref=dp_top_cm_cr_acr_txt/202-7575142...owViewpoints=1

All this is consistent with low end consumer DV camcorders so this one doesn't seem special. Some say progressive mode is useful for web work.

2. I can't select both 16:9 and progressive mode in the camera's menu. Why?
OTOH, I can select the 'cinema effect', which does just that (16:9 and progressive). Is it just a silly limitation or is there more to it?

There is processing between the single sensor and the DV encoder. All pixels are scaled and filtered.

3. The 16:9 and the 4:3 recordings have the same resolution (720x576) when I capture them to my PC. I've read about it here and elsewhere, so I have a slight idea about what's happening. But still: those two aspect capture a different "portion of the visual field". That is: 16:9 captures more horizontally, but cuts some vertically, while 4:3 captures more vertically, but cuts at the sides. (It's not that it just add black bars or anything like that). Which of the resolutions would you recommend? Which one is more native? (I'm suspecting 4:3 is, because of the 720x576 even for 16:9 recordings) ...

Sensors are circular. Cheaper camcorders sample a 4:3 window for both 4:3 and cropped 16:9. In this case 16:9 uses 70% of the pixels. Fancier camcorders map 16:9 wider but with less vertical area. All this is somewhat mute due to poor optics and the need to filter RGB from a single sensor.

When you step up to an HD consumer camcorder (HDV or AVCHD) the single sensor and optics design assume 16:9 but use a 4:3 1440x1080 (or higher/lower) sensor footprint. Turns out vertical resolution is more important than horizontal to handle both 1080i and 1080p plus circular lenses are far cheaper.

The Sony models still can't handle progressive at normal frame rates. The Canon HDV20/30 was the first that could handle 1440x1080p/23.976 in the US model. This is difficult to use because of 24F (telecined) transfer. I'm not sure how the "PAL" model works but I'd expect 25P sent as 25i interlace.

Can 4:3 recordings be stretched to 16:9 (in Vegas...) to produce the same quality video as if I recorded in the 16:9 mode?
BTW, The final product (DVD...) will always be 16:9, because that seems to be the standard now.

NO. 4:3 recordings are shown with sidebars on a 16:9 display. It is possible to duct tape your camcorder LCD to 16:9 if you can take the vertical resolution loss after crop.

4. I want to add a lens for a wider visual field. Like this one, for example. Any other recommendations or tips?
Also, what exactly does 0.7x magnification mean? Does it mean: If now I see 1m of the wall [from a certain distance] with that lens I'll see 1.7m of the wall?

I agree even for 4:3. Consumer camcorders are cheap because the optics are tiny. The optics are tiny because consumers don't like large camcorders. Tiny optics have limited zoom range at the wide end. Hence the price of tiny optics is you need to stand back 3-6 meters to see heads and feet. The wide adapter allows you to move closer (highly recommended) but at the cost of resolution and optical distortion. Pros use those big lenses for a reason. The other issue with small optics is limited light gathering. This means high noise in low light.

[ermi]

Thanks, guys!

About that Vegas error... yeah, it looks like I have to use an even number, odd numbers give me errors.

About this one:

So for 16:9 it should be 720x405. However, if I use that resolution I get black bars at the top and bottom. I have to use 720x394* to get rid of the black bars. Why is it so?

It makes sense if you divide 576 by 1.4568 (PAL DV widescreen pixel aspect ratio) = 395.387..... just doesn't make sense as a precise 16:9.

For the wide angle lens, you don't have to stick with your camcorder brand. Buy a cheap one (unless you are really serious about quality, etc.)

I use one of these:
http://www.amazon.com/SIMA-SLS-05-Wide-Angle-Conversion/dp/B00009K076
Works nicely for the videos I've shot

Yeah I'd rather buy a cheap one, actually. But does that one have some converters to fit different sizes of cameras? (I have 30mm.)
Oh and, noobish question, does 0.5x zoom give a wider view than a 0.7x?

[2Bdecided]

Users report jerky playback in progressive mode. This implies 12.5 fps single field in progressive mode.
http://www.amazon.co.uk/review/product/B0002K78NK/ref=dp_top_cm_cr_acr_txt/202-7575142...owViewpoints=1

A single field would give 25fps with resolution similar to 720x(576/2) - no one is doing 12.5fps any more (except in low light to increase the gain).

People report 25fps as stuttery because if you wave the camera around like normal people do, it is stuttery (or blury, if the shutter speed is lower). You have to seriously change your shooting technique to make it work.

Sensors are circular.

?! Not in any camera I've taken to pieces!

The Sony models still can't handle progressive at normal frame rates. The Canon HDV20/30 was the first that could handle 1440x1080p/23.976 in the US model. This is difficult to use because of 24F (telecined) transfer. I'm not sure how the "PAL" model works but I'd expect 25P sent as 25i interlace.

Yes, so you don't have to do anything to it. You can tell your NLE it's 25p if necessary.

I agree even for 4:3. Consumer camcorders are cheap because the optics are tiny. The optics are tiny because consumers don't like large camcorders. Tiny optics have limited zoom range at the wide end. Hence the price of tiny optics is you need to stand back 3-6 meters to see heads and feet.

To be fair, many digital still cameras have even smaller optics, and deliver a much wider angle - some dramatically so.

On camcorders, cropping the 4x3 sensor to 16x9 is a factor is losing heads and feat at what you'd think would be "normal" shooting distances - the 4x3 mode is fine, the 16x9 isn't. (Even the HV20 does that, but it has sensor resolution to spare so it's not a problem in terms of picture sharpness, but is painful in terms of always being too close to the subject indoors!)

Cheers,
David.

[ropdoh]

Yes, 0.5x wide angle has a wider angle than a 0.7x

This is how I think of it:
Think of it as the opposite to Zoom
using a 0.5x wide angle is the same as going from 2x zoom to 1x zoom
using a 0.7x wide angle is the same as going from 1.42x zoom to 1x zoom

That lens (SIMA SLS-05) I pointed to you on Amazon has about 6 adapter rings for various thread sizes. I go t mine a couple of years back, at circuit city I believe, I don't know how readily available they are these days

[edDV]

Users report jerky playback in progressive mode. This implies 12.5 fps single field in progressive mode.
http://www.amazon.co.uk/review/product/B0002K78NK/ref=dp_top_cm_cr_acr_txt/202-7575142...owViewpoints=1

A single field would give 25fps with resolution similar to 720x(576/2) - no one is doing 12.5fps any more (except in low light to increase the gain).

People report 25fps as stuttery because if you wave the camera around like normal people do, it is stuttery (or blury, if the shutter speed is lower). You have to seriously change your shooting technique to make it work.

The Panasonic AG-DVX100 is the lowest SD cam able to do true 24P progressive. If the newer line of Sony consumer camcorders could do true 25P it would be referenced somewhere in Google. I think they are sampling and upscaling a field which results in half vertical resolution and half motion increments vs. normal 720x576i DV.

I agree even for 4:3. Consumer camcorders are cheap because the optics are tiny. The optics are tiny because consumers don't like large camcorders. Tiny optics have limited zoom range at the wide end. Hence the price of tiny optics is you need to stand back 3-6 meters to see heads and feet.

To be fair, many digital still cameras have even smaller optics, and deliver a much wider angle - some dramatically so.

On camcorders, cropping the 4x3 sensor to 16x9 is a factor is losing heads and feat at what you'd think would be "normal" shooting distances - the 4x3 mode is fine, the 16x9 isn't. (Even the HV20 does that, but it has sensor resolution to spare so it's not a problem in terms of picture sharpness, but is painful in terms of always being too close to the subject indoors!).

The difference with digital cameras is optical zoom range (1-3x typ). Digital cameras with 8x or 10x zoom have lenses of similar size to camcorders. Zoom lenses that are wider at the lower magnification tend to be larger in physical size.
http://www.imaging-resource.com/WB/WB.HTM?view=dp_long

The sensor cropping issue differs for low end cams (left) and "prosumer models" (right). Consumer models often crop to 16:9 within the 4:3 area. This reduces both vertical resolution and the effective wide zoom range. "Prosumer" models sample a 16:9 area by adding pixels left and right without cropping the vertical.

[2Bdecided]

The Panasonic AG-DVX100 is the lowest SD cam able to do true 24P progressive. If the newer line of Sony consumer camcorders could do true 25P it would be referenced somewhere in Google. I think they are sampling and upscaling a field which results in half vertical resolution and half motion increments vs. normal 720x576i DV.

That's exactly what I said - and it gives you 25 (expanded) half-res images per second rather than 50 half res images per second - not 12.5.

The difference with digital cameras is optical zoom range (1-3x typ). Digital cameras with 8x or 10x zoom have lenses of similar size to camcorders. Zoom lenses that are wider at the lower magnification tend to be larger in physical size.
http://www.imaging-resource.com/WB/WB.HTM?view=dp_long

Thank you for explaining that.

Cheers,
David.

[ermi]

I bought a cheap lens, which includes both a 0.45x wide and a macro lens (this one). I took out the macro lens from that ring, so as to get all the width of the 0.45x. On the cam screen it looked ok, sometimes an edge would peek out at the corner, but still useable. But when I captured the video to the PC the edges were way more noticeable (see here).

Now what I'd like to know is: Is this a limitation of the camera itself, aka you just can't shoot this this wide at all OR would it still be possible to shoot 0.45x wide with a different lens?

The lens also distorts on the sides. A limitation of the lens or inevitable at this size?

[edDV]

Better to buy the wide adapter from the camcorder manufacturer to get the best optical match. A good wide adapter will be a large piece of glass. The wider the adapter, the more barrel distortion (i.e. curved edges and lost corners).
http://en.wikipedia.org/wiki/Image_distortion

To get good wide angle performance, you would need a larger pro camcorder. The lenses for typical studio cameras cost more than $5000 and are huge.

[ermi]

The widest lens from Sony was a 0.6x, which is not much, so I went for this 0.45x, which is way cheaper as well.
If I use it with the macro lens on then it's ok, no lost corners and minimum distortion... but obviously it has less magnification then.. maybe around 0.6x.

A good wide adapter will be a large piece of glass. The wider the adapter, the more barrel distortion (i.e. curved edges and lost corners).

Huh? Which one is it then? I don't want barrel distortion.
Or did you mean 'the wider the adapter' in relation to the built in camcorder lens?

Anyway, I'm not expecting much from this little camcorder, but I'm just curious if there are some technical limits for the viewing width or could everything be possible with a great adapter lens.

[edDV]

The widest lens from Sony was a 0.6x, which is not much, so I went for this 0.45x, which is way cheaper as well.
If I use it with the macro lens on then it's ok, no lost corners and minimum distortion... but obviously it has less magnification then.. maybe around 0.6x.

A good wide adapter will be a large piece of glass. The wider the adapter, the more barrel distortion (i.e. curved edges and lost corners).

Huh? Which one is it then? I don't want barrel distortion.
Or did you mean 'the wider the adapter' in relation to the built in camcorder lens?

Anyway, I'm not expecting much from this little camcorder, but I'm just curious if there are some technical limits for the viewing width or could everything be possible with a great adapter lens.

You get more barrel distortion with a wider adapter. The factory accessory magnification indicates the probable optimal.

Fish eye lenses take it further and always have curved sides that approach a circle.