AC90: 25P footage quality

Well, extracting frames and looking at it, there's something clearly very wrong. There's a massive quality difference, and there shouldn't be.

This is a dumb question, but in the interest of thoroughness I've got to ask: Are you using PH mode for the 25p? If you were using something like HE mode I might expect this type of difference, but of course you can't choose 25p in HE mode. So I just want to verify for certain that you're using PH for the 25p, and PS for the 50p...

Here's the kind of difference I'm seeing in your footage, at 300%.
25pvs50i.jpg

Here's the kind of difference I get from my AC90, shooting 30p and 60p:
30pvs60p.jpg

Now, frankly I'm a little surprised that there's a difference in my footage at all, I would have expected it to look identical, but I can see detail a slight bit better in the 60p version than I can in the 30p. But it's really, really close. Whereas with your footage, it's night and day.

I don't know why it's so different for you, but I can assure you it shouldn't be. How are you changing between modes -- are you using a different scene file? Or are you just going into the "record setup" menu and changing from ph 1080/25p to ps 1080/50p?
 
Hey Barry,

thanks loads for looking at the .MTS files.

Wow your tests are so much closer in quality huh.

Yes I am doing nothing at all apart from switching between 50p and 25p in the Record Setup/Record Format option.

50p is PS (PS 1080/50p) and and 25p is PH (PH 1080/25p).

Do you think the unit is faulty maybe?

I also wondered why the jitteriness on panning, almost as if frames are missing? But maybe that is the same problem as the image quality problem?

I sure need to get to the bottom of it anyway!

Thanks so much for your time and for checking it out.
 
Before I could say it's faulty, we would have to see someone else with a 50Hz camera duplicate this same type of test and see what differences they see. But my inclination is to believe that there's definitely something haywire going on, and you should most definitely not see such a tremendous drop in sharpness just by switching to 25p.
 
Thanks Barry, I'll ask Panasonic to look at these tests anyways, and wondering is there anyone else out there who would be kind enough to run a similar test?

Thanks again!
 
Yes that would be great Nathan. Thanks.

Does Barry have any thoughts on the jitteriness of panning shots? Is that a separate issue do you think? It's almost as if frames are missing, so a smooth pan looks kind of jerky.

Many thanks all!

Am off on hols for a week now so may not be able to look at stuff until after 18th!

Cheers.
 
Just to kick in again... I have the PAL version, too, and by now the test looks OK. But there was a time when I had the same results as you, but after the firmware update it looks good so far. Did you update your camera? In my old german manual it actually says "25p is recorded as 50i", and that was what I saw back then.
 
Hey many thanks, no I didn't update at all yet, maybe that would fix it!

Any idea why panning looks so weird tho? Maybe that's the same problem?

Or on the 50p maybe something to do with using 1/50th shutter speed shooting at 50p and then going back down to 25fps?

Will check it out anyway, just off on hols so might take me a coupla weeks now!

Thanks again all, really appreciate it!

Mark :-))
 
The problem with panning might be due to rolling shutter, which seems to be a commom problem with CMOS sensors. How fast is your panning?

After reading all previous posts I could imagine the panning problem being part of the OIS. Are you panning on a tripod or free handed? Do you have OIS on?
If it is on, the cam is trying to stabilize your pic, and the end of a pan looks extremely unstabilized for the camera, so it tries to compensate. That might be the source of your jittery frames at the end of a pan.
But then, it's just one possibillity out of many.
 
Hi, thanks for the reply! No the OIS is always off. And always panning off a tripod, pretty slowly! I will pull some of the worst pans and post them up.

Still trying to get to the bottom of the 50p/25p problem but back from hols now and chasing up Panasonic for an answer.

I've no idea how to update firmware, is that easy to do, any links/threads on that?

In the meantime will keep shooting at 50P and converting to 25p I guess!

Many thanks!

Mark
 
Firmware update is easy. Just copy the firmware file onto your SD card, push it in and select "Firmware update". There is another thread here about the latest firmware with all kinds of links and opinions.
 
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