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-   Sony HVR-V1 / HDR-FX7 (https://www.dvinfo.net/forum/sony-hvr-v1-hdr-fx7/)
-   -   Stills from FX7 Video footage (https://www.dvinfo.net/forum/sony-hvr-v1-hdr-fx7/486085-stills-fx7-video-footage.html)

Troy Davis October 13th, 2010 01:33 PM

Stills from FX7 Video footage
 
Hello,

A client wants to know what size stills can be produced from HD video shot with th FX7? They had problems with the photographers images and wants to print a few from the video capture. I'm assuming
that in order to get a good quality printed image the image would be somewhat small if saved at
the default 72/96 dpi? Any ideas?

Thanks,
Troy

Seth Bloombaum October 13th, 2010 03:03 PM

That's one of the things I noticed immediately when I got my V1; a decent shot really does produce a decent image, in come cases usable for print.

The actual still will be a 1440x1080 file, with non-square pixels. As I understand it, later versions of photoshop can correctly display non-square pixels. The pixel aspect ratio (PAR) of HDV is 1.3333, meaning that for correct display, the width of the pixel is multiplied by that amount.

The square-pixel equivalent is 1920x1080. This is what any graphics program can deal with, and the correct PAR of 1.0 is what you want for jpegs, pngs, tiffs, and all those other graphics file formats.

The question is, when you pull a still off your video, is your NLE doing this correction for you? If not, the images will have to be processed so as to increase the width by a factor of 1.3333.

Once you have your 1920x1080, this is an absolute pixel size. Translating that into graphics-speak, it would be an equivalent of 20"x11.25" at 96dpi, I think. I'm not expert on the graphics side. What I'd tell a client is 1920x1080 pixels.

Denise Wall October 13th, 2010 03:13 PM

Quote:

Originally Posted by Troy Davis (Post 1578375)
Hello,

A client wants to know what size stills can be produced from HD video shot with th FX7? They had problems with the photographers images and wants to print a few from the video capture. I'm assuming
that in order to get a good quality printed image the image would be somewhat small if saved at
the default 72/96 dpi? Any ideas?

Thanks,
Troy

One thing that can make these stills work better is a high shutter speed if there's any action or a lot of movement. I've shot video at higher shutter speeds than I wanted to because I thought I might need to pull stills later. It's usually something I start out thinking about, though, not something after. Even so, you can usually go frame by frame to find the best frame for a still. They often work out not so bad in a pinch.

Troy Davis October 13th, 2010 04:53 PM

@ Seth
You are correct. I did a test and it's just what you said. This will work just fine.

@ Denise
I will keep that in mind for future reference.

Thanks,
Troy

Bruce Dempsey October 13th, 2010 06:43 PM

From the video, the image is in two fields as interlaced.
The best stills can be achieved by combining the two and there are online tutorials somewhere

Victor Wilcox October 14th, 2010 08:00 AM

Adobe Photoshop CS3 and CS4 have a deinterlace video filter which does a good job.

Denise Wall October 14th, 2010 12:03 PM

two more things
 
Be sure to check the color space of the stills you pull in a photo editing program. The native color space may be in CMYK or uncalibrated. You'll need to convert it to an RBG color space to edit and look decent in print.

If you need to up res the image for a larger print than the resolution that you get off the camera will allow, you can do it up to a certain point. Just be sure to use the "bicubic smoother" when you resize to avoid pixelation of the image in print.

John Wiley October 15th, 2010 04:09 AM

I've used FX7 frame grabs for DVD cover prints regularly with very acceptable results. I once even had some A2 posters printed with a FX7 frame grab as the main graphic (it was a portrait orientation too, meaning that 2/3 of the resolution was lost when cropping the image to fit the poster) but this was for a very stylised poster with alot of PP so I could get away with the lower res.

For web use, HD frame grabs are great. For printing, there is definitely a few boundaries but you can certainly get acceptable results up to A4 if you are careful with things like shutterspeed, deinterlacing, etc.


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