I am an HMC150 newbie and have a number of basic questions that I am hoping more experienced users can answer.
The HMC150 Brochure says the camera has a "high-resolution native progressive 1080/60p scan" and warns that "the camera does not record this signal but uses it as a basis for all captures." I gather the camera actually does not do a 1080p scan but instead generates it from a 540p scan (since the imaging chips are 960 x 540). Ignoring that issue for now, I assume the camera starts out with the "equivalent" of a 1920 x 1080 progressive scan which can be performed roughly 60, 30, or 24 times per second.
1. What is actually output for 1080/60i? The first field of the interlace output presumably contains the odd numbered lines from the first frame of the 60 progressive frames. What about the second field of the interlace output? Does it use the even numbered lines from the second of the 60 progressive frames thereby introducing the ugly interlace artifacts of traditional NTSC? Or does it improve on NTSC by using the even numbered lines from the first of the 60 frames? That would imply using nothing from the second frame. That, in turn, implies that the HMC150 discards half of the 60 frames which means, in a sense, discarding half of the light. Is that true?
2. How are the "slow shutter speeds" implemented? In 1080/60i mode, what does a speed of 1/15th of a second mean? Does the output drop to 15 frames produced by summing the light from 4 progressive frames? Are the frames repeated in order to maintain the 60 fields? Or, are 60 fields generated with the exposure as some kind of moving average of 4 frames?
3. I assume that the camera actually slows its scan to 24 in order to output 1080/24p rather than doing some kind of conversion from the 1080/60p progressive scan. Is that correct? If not, how is the conversion done?
4. The SD Memory Capacity chart on page 32 of the Operating Instructions manual indicates that you get roughly the same recording time (file size) when shooting in PH (highest quality) mode whether you select 1080 lines or 720 lines. That seems slightly surprising. I would have guessed the 1080/60i files would be bigger than 720/24p files. The LCD display is consistent with the manual. The indicator for time remaining on the SD card (at the top left of the screen) does not change when you switch among the PH formats. Can someone explain this surprising behavior?
Thanks for any insight you can provide.
The HMC150 Brochure says the camera has a "high-resolution native progressive 1080/60p scan" and warns that "the camera does not record this signal but uses it as a basis for all captures." I gather the camera actually does not do a 1080p scan but instead generates it from a 540p scan (since the imaging chips are 960 x 540). Ignoring that issue for now, I assume the camera starts out with the "equivalent" of a 1920 x 1080 progressive scan which can be performed roughly 60, 30, or 24 times per second.
1. What is actually output for 1080/60i? The first field of the interlace output presumably contains the odd numbered lines from the first frame of the 60 progressive frames. What about the second field of the interlace output? Does it use the even numbered lines from the second of the 60 progressive frames thereby introducing the ugly interlace artifacts of traditional NTSC? Or does it improve on NTSC by using the even numbered lines from the first of the 60 frames? That would imply using nothing from the second frame. That, in turn, implies that the HMC150 discards half of the 60 frames which means, in a sense, discarding half of the light. Is that true?
2. How are the "slow shutter speeds" implemented? In 1080/60i mode, what does a speed of 1/15th of a second mean? Does the output drop to 15 frames produced by summing the light from 4 progressive frames? Are the frames repeated in order to maintain the 60 fields? Or, are 60 fields generated with the exposure as some kind of moving average of 4 frames?
3. I assume that the camera actually slows its scan to 24 in order to output 1080/24p rather than doing some kind of conversion from the 1080/60p progressive scan. Is that correct? If not, how is the conversion done?
4. The SD Memory Capacity chart on page 32 of the Operating Instructions manual indicates that you get roughly the same recording time (file size) when shooting in PH (highest quality) mode whether you select 1080 lines or 720 lines. That seems slightly surprising. I would have guessed the 1080/60i files would be bigger than 720/24p files. The LCD display is consistent with the manual. The indicator for time remaining on the SD card (at the top left of the screen) does not change when you switch among the PH formats. Can someone explain this surprising behavior?
Thanks for any insight you can provide.