Try some motion. Often I-frames become very small. Whenever that happens, P-frames spike up close to max I-frame size.

I might leave GOP parameter at default 24.

720p60 GOP6 AQ3 showed worse result. You could try it with AQ0.

For my working set, I will stay either AQ0 or AQ1 with GOP6. AQ3 for testing set.

I like 3.62d :)

AQ0 or AQ1 seems good enough for now... until we get 3.63d (???).

You know what we are hoping for. AQ4!!!

@cbrandin Thanks for the detailed testing suggestions using a series of underexposed takes. This is similar to the procedure I used for evaluating shadow detail in the GH1 Max Latitude Patch, and it revealed things I wasn't expecting to see. For example, I started to notice the tendency for low-quality static macroblocks to appear in the bottom part of the frame in high-detail images. However, I couldn't make sense of it until I read your explanation of how the AVCHD encoder behaves when it runs out of bitrate before it reaches the end of a frame...

Have we found a "best" 66mbs setting yet?

@cbrandin thanks, in the meantime i am shooting with:

Version increment=1
Video Bitrate 24H=66000000
Video Bitrate 24L=35000000
Auto Quantizer for 1080 modes=4 - All to details
1080i50 and 1080p24 GOP Size=3
1080p24 FB1=1566720
1080p24 FB2=1968046
1080p24 Frame Limit=15728640

Unless somebody knows issues with this set up i am about to walk out the door! The only difference is i used to shoot x3 then no x, now testing 2x, wish i had more time for this stuff right now, but yea i'm real eager for the perfect 66mbs =) i'll let you know how the above goes.

Ideal for close-ups and people in motion:
in mind an ideal setting in AVCHD Intra (GOP1) before averaging 45MBit

@OSGondar There is no such thing as a best 66Mbps. It's like asking what is the best preset for Lightroom.

Eventually we'd get a "range" of generally recommended settings as we understand enough characteristics of params over the range.

@stonebat "It's like asking what is the best preset for Lightroom." You are way off on that one. By now you may know what i mean by best if you ever bothered to read through threads rather than post a new one whining that you are not about to read that much, "give me answers".

Best for me..... a 66mbs that gives enough information in the shadows to effectively give more dynamic range when i pull them in post whilst having under exposed to save as much highlight as possible. I do mostly narrative work but on occasion i am camera man / dp for documentary as well so for those situations based on having a lot more motion run and gun ill adjust for motion etc if i must but i think mainly what i mean is the most detail you can pull out of 66mbs shadows without artifacts. this the " image quality" thread right? how to handle Motion is up to the user to adjust etc but to say its like like asking for a Lightroom preset is akin to me asking you how to color correct my footage, far from it. A raw file is aquired BEFORE importing it right? right, so that's where i'm at, i dunno what the hell you think your going on about but for future reference i'm not addressing you when i post, but thanks i guess, for the useless reply. if you have nothing to contribute don't reply for the sake of sounding like a smart ass.

@cbrandin I'm going to test my settings at gop 3, 6, 12 off etc. I read to avoid 3 for now, still i want to see what the effect is since i'm already out and about and i haven't seen any real footage comparing them, i have a shoot starting Monday and i really want to shoot at 66 because it still gives a good 1hr out of 32gig whilst a nice bump in birate / detail so i really hope to get it figured it out over the weekend. ie working settings or best image in 66mbs at moment, Thanks

@stonebat its alright, it did irk me but i had a long day of editing, my least favorite gig. I just really need to get closer to the work horse 66 because i am dp'ing a shoot a little too soon for comfort. I found little patience in the moment, i'm sorry as well. In any case its indeed Friday, enjoy

IMHO low GOP (3 or 6) lowers IQ with this version of PTool.
First few seconds run fine (even with 110Mbits / GOP3) but there is said issue with the uneven cadence and I-Frames go down to 6Megabyte and below.

Here are 2 settings that work for me fine so far (for 24p, 50i, 720p50 without B-frames). All GOP 12.
I've started with the settings of "mpgxsvcd" and then tuned them step by step with regard to settings of other users posted here. I-frames are higher than 9 Megabyte in both settings and the cadence is even.

Setting B:
Video Bitrate 24H=66000000
Video Bitrate 24L=32000000
Video Bitrate FSH/SH=32000000
Video Bitrate FH/H=24000000
Auto Quantizer for 1080 modes=4 - All to details
Auto Quantizer for 720 modes=1 - Some to details
720p50 GOP Size=12
720p60 GOP Size=12
1080i50 and 1080p24 GOP Size=12
1080i60 GOP Size=12
1080p24 FB1=3133440
1080p24 FB2=3936092
1080p24 Frame Limit=31457280

Setting C:
Video Bitrate 24H=52000000
Video Bitrate 24L=32000000
Video Bitrate FSH/SH=32000000
Video Bitrate FH/H=24000000
Auto Quantizer for 1080 modes=4 - All to details
Auto Quantizer for 720 modes=1 - Some to details
720p50 GOP Size=12
1080i50 and 1080p24 GOP Size=12
1080p24 FB1=1566720
1080p24 FB2=1968046
1080p24 Frame Limit=15728640

When you look at the screenshots of streamparser attached it's pretty clear that Setting B achieves larger P and B frames in the same scene.

There is one issue, though, with the 24p MTS files from this settings... and this is a serious one.
Avid won't import the 24p files (50i and 720p50 are okay). Clip Wrap does convert them but the files are trashed with weird artefacts (again this only goes for the 24p files).
5DtoRGB and Neoscene convert the files just fine. Also VLC and EyeTV can play back the files.

@towi

also with setting C have you problem with clip wrap?