HPX250: HPX250 synchro scan in progressive mode

[Gary Senda]

I'm going to sell my HPX171 and my Canon 7d to buy an HPX250. I have tried this camera for a whole day and I like it (excepts for the weight). I have noticed that with this camera synchro scan/shutter off in progressive mode is 1/25" (1/30" in 60Hz countries), that is 360°. This is completely different from all the other Panasonic camera I owned (DVX100, HVX200, HPX171 etc) and sincerely I don't understand why this choice: 1/25 give me too much motion blur and I can control strobing well with 180° shutter.

Someone know if is it possible to set the camera to have always 180° when shutter is off in progressive mode?

Thank you in advance for the answer

Regards

Gary

 

[brynsank]

All depends on which mode you are shooting in. Shutter off will by nature expose the sensor for the duration of the frame - so 24fps = 1/24, 25fps = 1/25, 50fps = 1/50, etc. Anything other than that cannot be considered "shutter off," and to achieve a different effect you will need to turn the shutter "on." That's how I understand it anyway. I believe this is the case because the "native" modes (24pn, 25pn, 30pn) available on the HPX250 (when recording AVC-I) do not employ a pulldown to conform them to the 50/60 standards as DVCPROHD does. So on the HVX, when you were shooting 25fps it was conforming to 720/50p or 1080/50i, so the "shutter off" was giving you an exposure of 1/50. You thought this was 180deg because you were shooting 25fps, but in fact it was not.

Someone please correct me if I'm wrong

 

[Gary Senda]

I have thought the same thing, but I have also an AF100, that record native 25p and the shutter off is 180°. This is the first time I see a Panasonic camera with shutter off at 360° in progressive mode

Regards

Gary

 

[Garion]

Brynsbank is correct, on the 250 and 370 shutter off is the same framerate as the film mode setting. 1080 25p is 25fps (shutter off but a little bleary), shutter on is 50fps (180deg sharper). on the 370 and i assume the 250, in the menus you can set the camera to display in degrees. When i did that on my 371 i could keep 180 deg shutter whenever i change mode 720- 1080 and never worry about mucking it up.

I believe on some of the other Panasonic cameras it is the other way round but the 250 follows the 370 ( as its really the same cam).

 

[Barry_Green]

The 250 and 370 act the same as the bigger broadcast cameras, shutter off = no shutter (or 360 degrees). Gary is right that all the other Panasonic handheld cameras all have shutter off = default shutter (usually 1/50th).

 

[evero]

The 250 and 370 act the same as the bigger broadcast cameras, shutter off = no shutter (or 360 degrees). Gary is right that all the other Panasonic AG-series cameras all have shutter off = default shutter (usually 1/50th).

wow, that's useful to know! I wrongly assumed shutter off equaled to 180 degree on the hpx250! so this means I have to set my shutter manually to 1/50 when shooting 1080 25pn to get the motion blur I usually want... (or did I miss something else here?)

and one more thing: If I understand correctly the same thing apply to 720 (50p). At least it seemes so when looking at the exposure on the LCD. BUT when I want to film in 720P, and keep a 180 degree shutter (want a little faster shutter because of planning to make 50% slow mo), it doesnt seem to be possible to choose 1/100 shutter. From 1/80 the next step is 1/120. This is problematic when dealing with european 50hz electricity/lights. Any idea why 1/100 is not an option??

thanks for all your insight. this forum is great!

 

[timbook2]

@evero : Its tricky and it took me a while to grok how to set almost 1/100 shutter but here is how it works: touch the dial select button til shutter comes and adjust you will see in 50i mode it will go 1/25 and 1/12.5 then 1/50.0. pick this and hit the dial sel button again multiple times and all of a sudden a third function appears: syncro scan.
In 25p lowering the shutter speed will get you one more setting 1/6.25 and then 1/50.0
if you pick this shutter speed you are in syncro scan! hitting the dial sel button you now have this 3rd option and can adjust either by speed or by angle (in menue/scene file)
If you now choose syncro scan you can set the shutter speed to 1/99.9 or 1/100.1 with the wheel ... no idea why it doesnt go to 1/100.0 but thats the closest you get and it works. Its futzy and complicated and irritated me at the beginning but once you got it its there.....

 

[Faust]

I believe this is the case because the "native" modes (24pn, 25pn, 30pn) available on the HPX250 (when recording AVC-I) do not employ a pulldown to conform them to the 50/60 standards as DVCPROHD does. So on the HVX, when you were shooting 25fps it was conforming to 720/50p or 1080/50i, so the "shutter off" was giving you an exposure of 1/50. You thought this was 180deg because you were shooting 25fps, but in fact it was not.

Someone please correct me if I'm wrong

I'll try ,
exposure time has nothing to do with pulldown methods, electronic shuttering happens at the top of the video chain while recording formats appear at a later stage.

Even the shoulder mounted AG-Hpx500 with no AVC-I (just like the AG-Hvx200) employs 2:2 pulldown to embed DVCProHD 25P in 50p or 50i streams, but setting SHUTTER "OFF" means you'll get the full exposure time of 1/25th of a second.
Or, in any case, a 360-degrees shutter angle.

 

[Barry_Green]

"shutter off" performs differently between the HVX (and DVX and HPX170) and the HPX250/300/370/500. On the HVX and HPX170, "shutter off" means use the default shutter speed, which is 1/50 in 24/25/30p progressive modes and 50i/50p, or 1/60 in 60i/60p.

On the HPX250 and the shoulder-mount cameras, "shutter off" means don't use any shutter at all, so it gives you 1/24 in 24p, 1/25 in 25p, 1/30 in 30p, 1/50 in 50i/50p, and 1/60 in 60i/60p. So it's the same as a 360-degree shutter.