[Ariis]

Hi,

I'm new to Pentax video shooting, and film making in general. I'm looking for good camera settings to have a decent video quality. Yes, I know that Pentax is not the right choice at the moment for film making, however that's what I have in hands now (and I didn't thought about making film when I bought it), so the image will be very soft but at least I hope to get something usable, and I can see here thanks to you (and the Pentax "Uncle Jack" little movie) that the gear is still capable of telling stories.

My question is about the Tv setting. I'm filming in M mode, and follow what I've figured out on Youtube about the best Tv settings, which is "double the frame rate". First, I'd like to film in 24 or 25 fps to be more cinematic, and I can't find the correct Tv value: no 1/48 and no 1/50 th of a second ! At least, my K-5 have 1/50th of a second ...but no manual mode (or no way to set the Tv value ; if you know how, I'm interested). Why did Ricoh removed the 1/50 value ?

So, when shooting at 25 fps, I have the expected movement blur, but also some kind of strobe effect that annoys me a lot, that I don't see on Youtube with other brand. So is it just me, or do you have this perception too ? Can we do something about that ?

[stevebrot]

I assume your questions are about the K-3? I am no video expert, but I can at least get things started:

• You should be able to set 1/50s in video M mode. Confirm that your exposure increments are set to 1/3 stop (menu/custom/c1/1).
• I don't know about strobe effect. Can you post an example?

[jatrax]

I know nothing whatsoever about video. However, if you are missing the 1/50th shutter speed check your setting for "EV Steps" in the menu. If set for 1/2 EV steps you do not get 1/50th. It is under C>1 menu.

[Ariis]

Hey, thank you for the 1/50s issue, you were right, it's available with 1/3 EV steps .

For the strobe issue, I'll make some video tomorrow, I can't send my test of the day. Thanks for this quick reply.

[richandfleur]

Where in the world are you?
Are you filming indoors? Under what type of lights?

[Steve.Ledger]

'Lorraine' is in France.
And yes, I believe also he may be referring to flickering caused by fluro's. Easy fixed by changing the shutter speed to 1/60 (if 1/50 is giving him flickering)

[kadajawi]

France is using 50 Hz though...

[Steve.Ledger]

France is using 50 Hz though...

Well, I don't think we're 100% sure what he's talking about just yet or even what actual frame rate he shot with.
But it's worth noting and putting it out there.

[richandfleur]

Well, I don't think we're 100% sure what he's talking about just yet or even what actual frame rate he shot with.
But it's worth noting and putting it out there.

This.


Still waiting on example or more info, eg does this issue occur when shooting indoors under artificial light, or TV's going or computer monitors etc...


Worth mentioning.

[kadajawi]

My bet is on stuttering motion... and if that is the case 1/50 should fix it, or even go to 1/25...

[Steve.Ledger]

Strobe is a verb which means to flash intermittently. This would not be consistent with stuttering motion but would be with a shutter speed out-of-sync with local electricity frequencies.
Perhaps the OP would be so kind as to follow up on what was the sole title of his thread?

[madhurvyas]

I think strobe effect is sudden change in expouser or light, like a studio strobe. Are you keeping iso to auto or manual? keep all settings in manual.

[Ariis]

Hi, sorry for the late reply, the weather very poor these days. Example shots are done, I'll post within the next hour. And my original post was about outdoor shooting under natural light, when panning with a very contrasty scene, but I also saw something strange under LED light that may be related (or not).

---------- Post added 17-08-15 at 14:18 ----------

Here are the examples:
IMGP1351-24fps_30 - panning speed 1
IMGP1352-24fps_30 - panning speed 2
IMGP1353-24fps_40 - panning speed 1
IMGP1354-24fps_40 - panning speed 2
IMGP1355-24fps_50 - panning speed 1
IMGP1356-24fps_50 - panning speed 2
IMGP1357-24fps_60 - panning speed 1
IMGP1358-24fps_60 - panning speed 2

I'd like to hear from you about which are irrelevant combination, but all of them shows a quite strong "flickering" (putting the word under quotes, as I don't know of a better word) when panning and find it quite disturbing. My question is : Is that really what we can get out of a 24fps film regarding "flickering" ? After some more search, I'm afraid that the answer is yes. But in the 2 following examples simulating a strong shake, it's doesn't hurt me at all. Is this related to the amount of contrast?

IMGP1374-24fps_50 - looks good even @ 24fps
IMGP1375-30fps_60 - looks good too

And yes, I'm from France, power supply @50Hz. I'm not an electrician at all, but considering that one Hz (one phase) has 1 low and 1 high, isn't the light flickering @100Hz in reality ? Anyway, forget about the LED light case, I've made my test again but under natural light and don't see artifact, so it was related to the power supply frequency. Disturbing but normal.

---------- Post added 17-08-15 at 14:36 ----------

For the record, here is what I get under natural light :


... and under LED light :


As we can see, the blur is very smooth under natural light while we can see 4 occurrence of the same letter in a single frame under LED light @ 50Hz.

[Ariis]

I assume your questions are about the K-3?

Yes, I forgot to mention that. I'm using a K-3.

[kadajawi]

I can't watch videos now, but as for the LED light... the problem is that some LEDs regulate the brightness by turning on/off very fast. Tends to happen with LED backlit TVs and monitors, and some LED light bulbs (the cheap ones I have in the living room right now flicker visibly... ). Not quite sure why a light bulb would try to reduce the brightness, especially since there's no way to increase it.