Overview We purchased the BM Studio 4K to ingest videos. The card worked great. When setting up the second rack of equipment we decide to save some money as we didn't need the 4K features and the Studio 2 looked like it would do the job as all of our captures were analogue or low end digital. The Studio 2 had some issues in our flow.
Studio 2 Issues
When testing we found that captures using the Studio 2 contained black frames "randomly" throughout the capture. The same tape captured using the Studio 4K worked fine. We used ffmpeg's blackframe option to test the files. One file had over 400 black frames and the same file had 4 using the 4K. During our testing we would replace the capture card, driver, and software in Rack#2 so that no other hardware was suspect.
I talked to Peter B for the Austrian archive and he mentioned that he recalled issues like that with the Studio 2 card.
The conclusion was that both Studio cards are designed for the broadcast field and both expect reasonably clean signals. If the signal drops below the tolerance level then the frame if made black! Obviously, Studio 2 has much lower tolerance than Studio 4K.
Solution
We bought a Blackmagic mini Analogue to SDI converter. In Rack#2 we feed the component from the TBC into the A/D convertor along with the audio. The A/D converter outputs the clean signal to the Studio 2 SDI input.