Quality of Capture card VS using Sparkcam/EOS Utility software with Canon SL3

Started by RoyZ, April 26, 2020, 12:48:55 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

RoyZ

Hello friends,

I have a question for those who might know, with the trial version of Sparkcam, I get some lag but overall I get a pretty decent video stream quality from my recently purchased Canon SL3 (250D) over USB.
The resolution through Sparkcam could be 1080p which is all I need (the camera could also output clean 4K)

The capture card I was thinking of is the BlackMagic Intensity Pro 4K.

But I was wondering what could be other disadvantages using Sparkcam or the EOS Utility software compared to a capture card as I wish to use my camera to capture and record video directly into OBS and don't want to loose so much quality.

Disadvantages I can think of:

1. USB is lower speed than a X4 PCI capture card, causing some lag and much lower FPS than the 50 or 60 fps I could get with a capture card (not sure if it's a deal breaker for me yet).

2. as it says in the specs, the "Color sampling method" of the camera could be: Uncompressed 8-bit YCbCr 4:2:2 or Uncompressed 10-bit YCbCr 4:2:2 or Uncompressed 8-bit RGB,
It sounds like "better color" to me then what I could get over USB but I don't know much about it and don't know if those specs really don't exist through USB with Sparkcam or the EOS Utility software.

On the capture card's website it says: HDMI Color Precision: 8, 10-bit (Deep Color) RGB 4:4:4 in all modes up to 1080p60, 8, 10-bit YUV 4:2:2 in all modes. so I might be able to get 10-bit 4:2:2 color with it?

3. The color spaces the the camera outputs could be: BT.709 / BT.601 / BT.2020, again not sure if those don't exist through USB. the capture card specs says:
Color Space: REC 601, REC 709. (no 2020) not sure if it matters but I have read that 2020 is the best/preferable profile and it seems this card doesn't have it. 

So I'm just thinking if I should get the capture card or not. Sorry for all the details, I wasn't sure what could be of use to you and what not..

Thank you so much for any help!

Roy.

RoyZ


Anyone? Anything? :)

I've just wanted to add I've just learned that the 2020 color profile is only good for HDR so that's not necessary.

I didn't see how I could edit my post so you could just scratch that third question off.

Luther

There's no comparison between USB vs capture card. USB will stream your liveview and it has a lot of limitations (resolution, bitrate, etc). With capture card you can get the same image (or even better) than what you would get while actually recording with the camera (no limitation of resolution or fps).
I'm currently using the USB liveview as a webcam (because of this quarentine thing), but it sucks sometimes. See detailed post here.
The cool thing with OBS-Studio is that you can make the color grading in real time. Use a Log picture style, input some 3dLUT (like ImpulZ or something) and do some fine adjustments with RGB curves. You'll get a pretty good image if you keep your ISO low enough (=<400).

RoyZ

Quote from: Luther on April 28, 2020, 04:36:48 AM
There's no comparison between USB vs capture card. USB will stream your liveview and it has a lot of limitations (resolution, bitrate, etc). With capture card you can get the same image (or even better) than what you would get while actually recording with the camera (no limitation of resolution or fps).
I'm currently using the USB liveview as a webcam (because of this quarentine thing), but it sucks sometimes. See detailed post here.
The cool thing with OBS-Studio is that you can make the color grading in real time. Use a Log picture style, input some 3dLUT (like ImpulZ or something) and do some fine adjustments with RGB curves. You'll get a pretty good image if you keep your ISO low enough (=<400).

Thank you Luther, I have seen your thread before. which also mentioned digiCamControl which I didn't know and looked for a software like it.

Funny you mention color grading, I've just watched and tried this tutorial:
https://www.youtube.com/watch?v=ogZU4fRt59I


I still don't have my final lighting setup so I don't have the final LUT file but I've learned about it and made sure it works.
I've also read that OBS takes 3D LUT files now and watched another video about how to produce 3D LUT files from DaVinci Resolve for color grading in realtime in OBS while creating the LUT file in the free version of DaVinci Resolve and it has worked great:

https://www.youtube.com/watch?v=PzFw4tjPqfE

I've learned about the difference between a 1D LUT to a 3D LUT here: https://affinityspotlight.com/article/1d-vs-3d-luts/

About the capture card VS liveview over USB.. I just needed someone else to confirm that USB is not really usable for production.
I just see the good quality of the DSLR through the liveview through USB and think.. do I need any better?
but as I'm aiming for the best quality, I might go with the capture card. still considering since its a $200 expense.

Luther

Quote from: RoyZ on April 28, 2020, 02:33:05 PM
I just needed someone else to confirm that USB is not really usable for production.
Not really. Besides the low resolution output (480p), the camera also stops the liveview ever since in a while. So it's not suitable for live streaming. The battery also drains pretty fast, because you need to keep the liveview on (I disable global draw and keep the liveview brightness as low as possible but still, the battery drains really fast).
Quote
still considering since its a $200 expense.
You can get cheaper ones, as long as it has HDMI input. There's no need to get something that expensive.