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Topic Title: Best video camera for streaming input
Topic Summary: What format does Screenflow accept from video camera
Created On: 11/24/2009 5:48 PM
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 11/24/2009 5:48 PM
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Robert73

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Joined: 11/24/2009

I'm about to buy a video camera since I don't find the quality of my iSight good enough. However, it's a jungle out there and I find it difficult to understand what possibilities there are. First of all, Screenflow accepts webcams but as I've understood a DV-cam works as well. And mpeg2 is not supported. So does that mean that I can go for any DV-camera including HDV and mini-dv?

The second question is, what's the quality when streaming directly in. Surely screenflow can't capture a full 1080p-stream, right? Is the framerate reduced? Since I'm on a macbook pro then firewire is the only option but I will be stressing my computer aside from the capturing so will it cope?

Third, I've tried to import a fullHD mpeg4 (1080p and 1080i) and that's too much. Isn't there a "prerender"-option if needed to be able to see the edits?

So with risk of sounding a little stupid, the goal resolution will probably be half of my macbook pro-screen (720*450) so am I aiming too high using HD? I'd like to use exactly 720*450 with the external video camera, but it seems like almost all of the prosumer cameras today only offer 1080 so what should I do? Buy a mini-dv-camera even though it says it writes mpeg2? haven't found anyone that is specified to write in other format.

If anyone of you are using an external video camera as input to screenflow, please reply with what model and if it works well. Guess I'm not the only one wondering.




 11/25/2009 10:39 AM
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DrJ

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I'll second this question. I'm also interested in moving to a DV or min-DV camera. I see that some stream on USB, others on FireWire. I want a sharp image, with a steady frame rate and the ability to produce good video under moderate lighting. [I'm already sweating from the lights I've got running during the podcast! I don't want to add any more.]

Anyone got any suggestions? Guidance?

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Dr. J
Podcast Host, "Lighting the Lamp"
Accordance Bible Software
 11/25/2009 12:09 PM
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cybchris

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For your target final resolution, I would go with used standard-definition DV camera that supported a 29.97 fps (or if you're in a PAL country, 25 fps) "progressive scan" mode so that you don't get interlacing artifacts. Don't be swayed by cameras that offer 24 fps progressive scan; they have to add "pulldown" (which introduces a form of interlacing) on their video output. In general, this rules out most Sony cameras; Canon cameras have supported 29.97 fps progressive scan pretty much from the beginning (I'm still using an ancient Optura from them). These are pretty much FireWire cameras.

Other comments/tips:

- ScreenFlow does not compensate for the non-square pixels used by pretty much all standard definition video cameras. I have a template project where I imported a 655x480 pixel dummy still image; I capture from the DV camera, and scale its width to match up with this solid to compensate for the non-square pixels. Then I delete still image.

- Consider seeing yourself at less than 100%. I set up a virtual stage in ScreenFlow using a cool abstract background image that had an illusionary floor and wall, scaled down my video 50% (which also sharpens it...while also obscuring some unwanted details like some lines in my face), and used reflections and drop shadows to make it appear as if it was sitting on this floor. An example is here: http://www.lynda.com/home/Disp...ourseN.aspx?lpk2=52293 (click on the Welcome post).

- To compensate for less light, put your camera into manual aperture or shutter speed mode. Longer shutter times (larger aperture settings) mean longer exposures, which means the ability to accumulate more light. Side effects: more "motion blur" if you move or wave your hands (as the shutter is open longer each frame, capturing more movement), and a deeper depth of field (which means things in front of and behind you are more in focus, for better or worse). I personally go the other way: small aperture setting, smaller depth of field (to blur out things behind me), and more light (I recently switched to "cool" lights - ones based on compact flourescents).

- You can leave auto-exposure on to compensate for varying light levels.

- I now manually white-balance the camera to get truer colors, especially under artificial or low light situations. I set a large piece of white foam core in front of the camera, go into its menu, and white balance it; much better results than my early days when I relied on the camera's auto white balance (especially given the cream - not white - walls in my room).

good luck -
Chris
 11/25/2009 6:54 PM
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CraigS

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As Chris notes, DV is good for ScreenFlow and Progressive scan avoids the interlace jaggies.
HDV cameras generally can also output DV. Firewire cameras do seem to be on the decline.
We're looking at HDMI in but that would require the user buying an additional box. I can't say yet when this will come to fruition.

If you want to get fancy with lighting you can create a key/fill light situation to avoid that flat look (often seen in live news and talk shows). Using a lamp with positionable light can help so you can move the lights without moving the whole lamp. My lamp has 5 bendable arms. Also sometimes manual white balance can look too "natural" and some people like to push to the warm side. You can use a "warm card" (it's a light blue card which shifts the video slightly to the red side) or otherwise shift the color temperature a bit if your camera can do that.

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CraigS
Telestream Desktop Forum Moderator
 11/26/2009 6:19 AM
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Robert73

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Joined: 11/24/2009

Thx for the great replies.

Despite your suggestions, I think I'm gonna go for a modern 1080p camera anyway. I've borrowed a Panasonic HDC-SD100 and tried. Sure, it's more work importing it separately but it has other advantages such as future-proof if I do want to go for HD-tutorials later on (and for other purposes then screencasts). Right now my biggest problem is that Screenflow crashes often when importing full hd-material. Haven't tried so much but it seems that 1080p in HDAVC-codec and .avi-container works and converted to 720p even better. By the way, yes, I'm in a PAL-area so this camera records in true 1080p with 25 fps.

A following question is the output format. When I tried 50% of my macbook pro-screen it got a little too small to be able to read well so I'm thinking that maybe it's better to go for a bigger format and instead drop the framerate. This video will be streamed only and I'd like 1 Mbit-users to be able to see it. Maybe I'll go up to 2Mbit if it's needed but then I'll probably make 2 versions, one small and one big not to exclude anyone. This leads to the question: what framerate can a 25fps movie be downscaled to with good results? 12,5 I guess but is that supported by for example Flash and other media players? And that leads to the last question...

How to publish?
There are varous streaming options out there but I'm a little lost here too. The coolest would be if the user can scale the movie themselves (as VLC) but I haven't seen that feature anywhere on the web yet. That would solve the problem with going for a too big resolution like 1440 * 900 that surely will not be viewable by all users. Suppose that is not possible it at least would be great to have a videoplayer that you can "jump" forward in. Many of the flash-streamers it seems that you can only jump forward if that frame is already downloaded. The video player from Longtail (http://www.longtailvideo.com/) seems to be ok but maybe there are better options. Any suggestions?
 11/26/2009 5:11 PM
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DrJ

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Thanks, cybchris and CraigS, for the replies. Very helpful indeed. I'll second Craig's suggestion about the three-way lighting. Viewers have said it makes a big improvement in the view-ability of my podcasts. [And I thought the goal of lighting was to ELIMINATE the shadows!].

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Dr. J
Podcast Host, "Lighting the Lamp"
Accordance Bible Software
 11/27/2009 2:59 PM
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CraigS

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Robert73 when you say you have problems importing HD is this files or an attempt to live record? Certain files types can certainly be at issue. They should be Quicktime compatible. GOP based codecs are more difficult for the CPU to decode too. Large files also take up more memory (RAM) so these are all factors to consider when using HD.

Trying to find the best export settings for web viewing can be tricky. Sometimes you have to make the size smaller to keep quality at the target data rate. Dropping the frame rates can help with the quality at a given frame size and data rate. You may notice less than smooth motion. Sometimes the only way to keep it readable is to do zoom ins in ScreenFlow. Wide to generally let the viewer know where to go and then close to see the text.

As for large sizes, YouTube can now handle 1080 (1920x1090) and the user can select it (HD) and then go full screen. Vimeo does this with 1280x720 and doesn't have the 10 minute duration limit. Generally any navigation requires the section to be buffered to move forward (or back). That's how progressive download works. Only if you use a live streaming server can one move ahead to a point not yet buffered. You'd have to look into a CDN or setting up your own server with lots of bandwidth. Streaming server fees tend to be a lot higher than progressive download.

Good lighting often involves the creative use of shadows. Eliminating them looks flat. Watch how interviews look on the news magazine shows like 60 Minutes or 20/20. If you're looking for a small desktop soft light kit (softens shadows) the Lowel Ego lights work for that. You can make one yourself though. You need something to diffuse the light basically.

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CraigS
Telestream Desktop Forum Moderator

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