why do stills from the HVX look SO bad?

F

filmguy123

Veteran
Shooting progressive HD (720p30p), which is 960x720. Now I know that's much less resolution than even a cheap 5 megapixel digital snapshot camera....

however, the image is progressive (so no interlacing), the lens is much better and I would think the image produced would be much better, it certainly looks better when played back as video...

And I'm not talking about blowing up the 920x720 picture, just leaving it at native size viewing it... it looks terrible.

Why?

I am importing via FCP, and using quicktime conversion to export as a still image file (.jpg) - I am guessing the problem may lie somwhere here, but I am not sure. Is this inevitable once compressed to DV? Or is there a better way to extract a still image?

Thanks!
 
This makes perfect sense..

The color resolution in video (generally) is a lot lower than thos 5 mp stills you're refering to, so is the size. Video is much more allowing for this than stills. Have you done some calculus on the bandwith needed to push them still jpegs through your timeline?

Gunleik
 
progressive is NOT 960x720. Scaling the image down to 960 is what it degrading your image.
Here is a 720 24pN HVX still from raylight avi footage saved as a psd still from AE. The only compression in this image is from saving it as a JPEG to post it. This is the first time I ever used the camera.
lsdplay001pn7.jpg


Are you sure you are using an HVX? Does it say Sony or Canon on the side?
 
You're not going to get a coffee table book images out of any video camera, but the HVX resolves nicely for stills at equal or lower resolutions.

1204719564.jpg


ND6, Open at Z99 (55mm) straight from Vegas timeline, cropped / resize in Photoshop, no correction

1204719780.jpg


Same settings under cloudy sky.

e
 
GUnleik - are you referring to the colorspace of video being 4:1:1 or 4:2:2 for HD on the HVX?


Arson and Erik Olson - those look much better than the results I got. Although, I did mention that I wonder if my problem has to do with the way I've exported in FCP, and both of you mentioned "from vegas" or "raylight AVI" - I am not in Windows, I and I don't have any of those apps.

Is the way I am doing things in FCP affecting this? What might I do differently?
 
Arson said:
progressive is NOT 960x720. Scaling the image down to 960 is what it degrading your image.
Click to expand...

Well... Progressive doesn't really say ANYTHING about rez...

The HVX records to a format - DVCPRO HD. DVCPRO HD scales 1080 anamorphicly to 1440 x1080 (PAL) or 1280x1080 NTSC and 720 to 960x720

So that's for what is recorded on the HVX pixel-wise.

Yes, I was referring to DVCPRO HD being 4:2:2 and not 4:4:4 (or 4:1:1/4:2:0 for that matter :) ), which means that you do have full "codec defined rez" in luma, and less rez in chroma. Have a look here:
http://www.adamwilt.com/pix-sampling.html

There is a really nice little article by Barry somewhere here.

The HVX is doing some nice little up- and down scaling tricks of itself, that I for the record don't see as bad at all in most circumstances...

I guess scaling in software might be part of your issue, and it's possible that raylight does a better job of scaling than FCP, I don't know, but my main point is that:
Nope. The HVX is not a still cam... It rather a nice little video cam.
Also if you've been doing a bit of colorcorrections and effects, you may easily throw away a bit of rez. Try setting your render prefs to High Prcission YUV for final output, and see if that helps. (FCP defaults to 8-bit for speed, which is mostly good)

Try this.
Open the file in QT (instead of FCP) and copy a frame (apple-c) For this to function, you need to show the video @ 1:1 scale on your screen.

Make a new photoshop document. Paste.
A/B that with your FCP exported frame.
Sometimes this works better, sometimes it doesn't...

Also how your still image "looks", depends quite a bit on how it was exposed, motion, shutter-speed, 35mm adapter, lighting, treatment in post etc. as the three above images above vividly illustrate.

IF you do heavy CC and "other treatments" to an image to get a good still, you could also try to render out to a better codec than DVCPRO HD - given that you have set the sequence to "high precission YUV"

But in short: The HVX is a lovely little video-cam, and you CAN pull stills from it. They'd better be not to blown up for web use, and half the 300 dpi size (IMO) or less for print.

Which means (sorta) you MAY get a usable 8x4,5 cm printable image out of a 1080 HVX image, given that all factors play your way. More often I'd suggest you took that little 5mp cam with you to get that still....

Gunleik
 
I think I know what he's talking about. I've experienced crappy image grabs off my FCP timeline. Sometimes when I would export via quicktime conversion to a still file, it would export at half resolution and be all pixelated and look simply awful. It wouldn't happen all the time. I never figured out what the cause of it was.
 
I've had the same problem when trying to export from FCP to stills. If you don't need a lot of individual frames, then opening up in Quicktime and copy/paste works great.

For example: http://www.leftfootmedia.com/mypics/Bark.png

If anyone does know of a better way to export from either FCP or AE and get individual frames like one would expect, I'd love to know. I'm sure I will have this need again soon. When I export my projects from Lightwave I do individual frames not avi or mov files.

Ho...
 
I use my hvx for stills every now and then. This is a 720 24p frame shot. Edius is great for exporting still images. This pick is uncompressed at around 2.6mb

Citation.bmp


This one is highly compressed jpg at 82k...

Citation1.jpg
 
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1280x720 is the pixel resolution for 720 footage.
If you keep insisting that you are correct to use 960x720 you are doomed to turn anything you shoot into absolute crap. You might as well be scaling it down to 720x480 and then complain that it doesn't look good.

Filmguy. I use Raylight to convert HVX MXF footage into AVI. Ive had the HVX since before Premiere supported MXFs. Raylight is a codec and converter that can be found here: http://www.dvfilm.com/raylight/index.htm The author (Marcus I believe) posts on DVXUser.


NOTE: if you have brought your progessive footage into an interlaced timeline and export a still you will be exporting an interlaced frame that is every second line of your image. You need to make sure your progressive footage is in a progressive timeline, or your NLE will be interpreting each frame into 2 fields and only exporting one of them.
 
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filmguy123 said:
Shooting progressive HD (720p30p), which is 960x720. Now I know that's much less resolution than even a cheap 5 megapixel digital snapshot camera....

however, the image is progressive (so no interlacing), the lens is much better and I would think the image produced would be much better, it certainly looks better when played back as video...

And I'm not talking about blowing up the 920x720 picture, just leaving it at native size viewing it... it looks terrible.

Why?

I am importing via FCP, and using quicktime conversion to export as a still image file (.jpg) - I am guessing the problem may lie somwhere here, but I am not sure. Is this inevitable once compressed to DV? Or is there a better way to extract a still image?

Thanks!
Click to expand...
Not sure if it is the compression because I compressed a 2.6+mb hvx still that looks ok then compressed the crap out of it for a 82k jpg img.

Before you spend to much time on this I'd like you to read an article in HDVideoPRO Magazine (with James Cameron on front) February Issue.... Article is "Pixels Ain't Square Dude" and that title will explain why...Great article!!!!

If you can't find it let me know I'll scan it and email it to you :)

Thanks ::)
Chip
 
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Feel free to PM me with your footage you want still shots from and I'll walk you through on the phone how I do it, and then we will post our results to benefit the board.

ChipG

Send me a PM anytime :)
 
Follow up with an arcticle in December HDVideoPRO "Is That Video Uncompressed?" Very interesting... If you want to read it I can also scan it and email it to you. :)

PM me anytime
 
Arson said:
1280x720 is the pixel resolution for 720 footage.
If you keep insisting that you are correct to use 960x720 you are doomed to turn anything you shoot into absolute crap. You might as well be scaling it down to 720x480 and then complain that it doesn't look good.
Click to expand...


The camera only records from 3x 960 x 540 CCD, pixelshifts that to 1920 x 1080 internaly (according to Panny/Barry) and scales that down to a format that only records 720 as 960 x 720. Then the NLE stretches the video to cover 1280 x 720, so there happens indeed quite a lot of pixel wizardry from the originally captured 3x 960x540 imaage to the final delivered anamorphic 960 x720 image. This is totally independent of which NLE you're using.

I don't say this is bad, in most cases it's an excellent solution and for the price, when the cam was released - it was unbeatable.

Gunleik
 
gunleik said:
The camera only records from 3x 960 x 540 CCD, pixelshifts that to 1920 x 1080 internaly (according to Panny/Barry) and scales that down to a format that only records 720 as 960 x 720. Then the NLE stretches the video to cover 1280 x 720, so there happens indeed quite a lot of pixel wizardry from the originally captured 3x 960x540 imaage to the final delivered anamorphic 960 x720 image.
Click to expand...

You seem to be implying that the original image in the camera is 960 x 540. The original image in the camera's sensor block is 1920 x 1080. The image is not "pixelshifted"; the chips are offset so the image is spread out over a 1920 x 1080 array.
 
I have good results with hvx stills and I use FCP.

Normally I do the following:

Import the P2 files from the cards into FCP. Now they are .mov files located in your scratch disk. Settings are, DVC PRO HD codec, 960x720, 16:9 pixel ratio.
If you dont need any color correction, open the file (something like 1234UI.mov) in quicktime pro, select the frame, put it on actual size, and copy the image (cmd+c).
Then you can cmd+v in your favorite photo editing software or even in a mail message.
Usually what degrades the color is exporting from dv files or not having your quicktime in actual size, it really copies the picture in the size you have on display.
 
KMR said:
You seem to be implying that the original image in the camera is 960 x 540. The original image in the camera's sensor block is 1920 x 1080. The image is not "pixelshifted"; the chips are offset so the image is spread out over a 1920 x 1080 array.
Click to expand...

The 960x540 chips are offset etc.

Exactly what I'm saying, other words, though :)

And I'm not implaying anythning other than that the native rez pr channel is 960 x540. And that's fine. But if that isn't pixel shifting, then what is?

I don't mind, though. We have 5 of them here and knew this when we bought them...
Happy as can be, actually - for most uses. So don't take this as bashing.

Gunleik
 
I export stills out of the FCP timeline using quicktime conversion. Just make sure you go into the options menu and select everything as the highest. I usually use PNG's or TIFF's.
 
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