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-   -   A Theory... (https://www.dvinfo.net/forum/still-crazy/12945-theory.html)

Riley Harmon August 7th, 2003 12:42 AM

A Theory...
 
I was shopping around my local mall today just looking at technology...to my surprise I ended up looking at cameras. I picked up a Sony CyberShot 3.2 MP digital still camera, I can't remember the model number. But I noticed that the camera has video out and a lot of digital stills have video out. Then when I got home I did some research on this.

Look at this page at the text underneath the table of movies.

http://www.ncsu.edu/sciencejunction/route/usetech/digitalcamera/monitor/vidoutput.html

When checking out the Sony, the preview on the LCD looked like 30fps progressive. I'm sure you can get different effects using different shutter speeds.

But after that intro, here's my theory...
What if you took a 5MP Sony Cybershot and hooked it up to a Portable Mini-DV TVR via composite, and used the digital still camera as a VERY high quality image video camera...? I am very curious if others on this forum have tried this. If so leave your opinions. I talked to a friend who tried it and he said it looked good on a tv except for a low blurry frame rate, and focusing...BUT the Sony 5MP I'm looking at has a manual focus ring, and my friend said that the preview on the LCD also looked blurry, so possibly since the preview on the Cybershots is very good, maybe it will give a verygood video out frame rate. Post your theories or comments about this.

Frank Ladner August 7th, 2003 06:49 AM

interesting
 
That's pretty creative.
I tried the same thing a few years back. The refresh rate on that still camera (It was an Olympus. Don't remember what model) was slower than 30 fps, but it looked good for that reason.
However, like you mentioned, it would not focus manually very quickly, or adjust exposure fast enough.

I would get some resolution charts and see just how much detail is getting passed through to the TV.

If you are able, please post some AVIs for us to look at. I'd like to see some.


,Frank

Riley Harmon August 7th, 2003 12:58 PM

Works
 
I went to my local staples hooked up a sony cybershot to my dv cam and recorded it, it looked amazing, it looked like film, probably b/c of the refresh rate of the preview, just think, cramming 5 mp into 720x480, all i need to figure out now is how to turn off the display settings, so they dont show up on the recordings, other than that is awesome, highly recommended. you can also turn off the power save, and it takes AA, NO MORE CHARGING! you'd only have to charge your recorder

K. Forman August 7th, 2003 01:02 PM

The only problem I can forsee, is that the still cam wouldn't give interlaced video. This is something you would have to do in post.

Imran Zaidi August 7th, 2003 01:21 PM

But wouldn't the purpose of this be to get progressive, not interlaced video?

Vladimir Koifman August 7th, 2003 01:26 PM

To my knowledge the current generation of digicams is unable to scan 3 or 5 megapixels at 30fps. Instead they read just a fraction of their pixels to produce live preview, like every 5th pixel or such.
They even build a special fast read-out path inside CCD just to do this.
So, basically, your theory leads to reading every 5 or 10th pixel of still camera sensor. Most of the pixel are just wasted in this mode.
In good light it might look ok, but I'd expect big problems in low light, either huge noise or darkness, depending on camera. Also, in preview mode most stills cameras are smearing like crazy. Try to point them on any light source and see it. By the way, this smear is not there in their final full-resolution picture.

Gints Klimanis August 7th, 2003 01:39 PM

In another thread, I commented on the CCD scanning algorithms used by digital cameras. At similar shutter speeds, digital
cameras produce images with motion artifacts. Check out
the triple sticks of the leftmost fighter, snapped with my Canon S40. On film, this would be a smooth blur. On my vx-2000, this is also a blur.

http://home.att.net/~gints/download2.htm
Check out the picture at the bottom of the page.
Shutter speed = 1/60
Brightened in Photoshop.

Riley Harmon August 7th, 2003 07:11 PM

do you think its worth it then? i mean i can get a 5mp digital camera alot cheaper than a 3 ccd camera, and the quality i saw was pretty good...i dunno whats your opinion

Riley Harmon August 7th, 2003 07:20 PM

a weird thing i noticed while watching the playback, is that when the camera was switched to camera mode not all of the image fits the screen its slightly smaller, but when the camera is switched to movie mode(low res MPEG) it fills the entire screen

Riley Harmon August 7th, 2003 07:46 PM

the video on a tv is pretty good...the model number on the sony is dsc f717, if anyone has had any expeirence with this unit, please post your comments...i will be posting frame grabs from the video, i must warn the frame grabs dont look great at all but the actual video does look good on a tv but to send it to you guys it would have to be uncompressed, otherwise it doesnt look good.

here is a review of the camera

http://www.dcresource.com/reviews/sony/dsc_f717-review/

Vladimir Koifman August 8th, 2003 05:41 AM

<<<-- Originally posted by Gints Klimanis : In another thread, I commented on the CCD scanning algorithms used by digital cameras. At similar shutter speeds, digital
cameras produce images with motion artifacts. Check out
the triple sticks of the leftmost fighter, snapped with my Canon S40. On film, this would be a smooth blur. On my vx-2000, this is also a blur.

http://home.att.net/~gints/download2.htm
Check out the picture at the bottom of the page.
Shutter speed = 1/60
Brightened in Photoshop. -->>>

Gints, can it be because of stroboscopic effect of fluorescent light? The artifacts are more visible on the left guy's stick, who gets more light as well.

Riley Harmon August 8th, 2003 12:42 PM

I have another question, do you think that using the av in of the dv camera will decrease the quality? like do you think that there is a better way to get the av out of the still cam to the av in of the dv cam. besides RCA

Frank Ladner August 8th, 2003 01:02 PM

Riley: Composite is the only way you can go out from the still cam, right?

I haven't seen a still cam with s-video or anything else on it yet.

But, using analog inputs will lower the quality. I doubt you can really tell just by looking at it, though, since you are recording to a DV tape instead of something like vhs.

Riley Harmon August 8th, 2003 01:32 PM

both cameras have a 3.5mm jack, and the cable goes from 3.5mm to rca, is there a cable out there that goes from 3.5mm to 3.5mm that is higher quality than rca


I mean i need really high quality video that produces the color of a 3ccd image, and this cybershot does well with colors, but do you think I'd get a better image through the Panasonic GS70 thats a low price 3ccd solution, only problem is that i've heard good and bad things about it, ugghghgghhg i just need to make a desicion...

Jeff Donald August 8th, 2003 04:56 PM

You are wasting your time. The output of a digital still camera will not equal a comparably priced mini DV camera. Stop fretting and decide if you need a video camera more or a still camera more.


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