Motion blur, frame rate and shutter speed

[MikesMovies]

Hi guys

A little advice please.

I recently made this movie https://www.youtube.com/watch?v=HcXfsY2uA5Y&t=34s

While overall I am pleased with it and the Chrom key was really nice to work with for once lol (blue and green used)

I know the camera (Canon GTx mk2) was close to the action but there seems to be a lot of blur as the trains pass by.

Camera settings were 25fps Pal, shutter 1/100th and between F9 and 11 depending on needs. ISO was 2500.

Can anyone suggest how i could improve this please? would using a faster shutter or 50fps help?

Regards to all, Mike

[Scubbie]

The blur motion you are seeing in the video I would classify as "natural". Depending on your camera, it may be possible to increase or decrease the shutter speed to change the blur effect. I typically shoot at 50fps or 60fps on two of my cameras. This means that I don't see any blur on some subject where blur is desirable. On these two I do not have the option to reduce to 25fps when shooting HD.

What I'm not seeing it an artificial angle caused by the motion of the trains. That for me is a good thing and something which there is an add-on that you can buy to correct if it was there.

I like the idea that you've put together there. I would suggest that you look at a couple of technical things...

1. Ensure that the camera is level. It may help to use a spirit bubble if the camera doesn't have this. Although a couple of my cameras have a digital spirit level I bought a bubble one as it can be easier to see in some cases
2. If possible you might benefit if you can shoot using a remote control app. I can't find the Canon GTx mk2 listed, but I did find the Canon GT7 MkII. In the user manual, it mentions an app you can use with your mobile phone (or tablet). This may reduce the times where you've apparently moved the camera up or down a little between shots
3. Some model railway enthusiasts have made their stock look a little dirty. Perhaps as you're putting the camera so close you may find this a good idea, but get advice from someone who's done it before if possible
4. Consider the background images a little more. You're focusing sharply on the rail stock, but the background is in focus too or the relative size is out of proportion. I would consider going out shooting some "stock footage" and manually setting the focus to about where the railway stock will appear. I'm guessing that you used still photos, where a video could be more challenging but more 'realistic'.

There is always a danger when you increase the ISO that the footage will appear grainy. The footage you've shown here doesn't appear to have that.

What you've done is a little different and a vast improvement on some of the earlier results. Good luck!

[MikesMovies]

Thanks so much Scubbie

The camera was placed on the model railway on a rubber mat.

I have tried to understand this up and down movement I see and really don't understand it as I simpy start the camera filming, run the trains then stop it filming???

That's an interesting thought re the background. Maybe I should have it a little out of focus, I am trying a video background this evening, I think the scale is wrong to be honest but it looks quite good.
Won't be up for some hours due to slow upload speed here.

Thanks for the encouragement I'll try and put it into practice!

[Scubbie]

I know just how hard it can be to spot the slightest movement when you are wanting to record lots of video in the same spot. There can be a few ways around this.

The first would be to have a different shot between two recorded in the same place, thus avoiding the obvious movement showing when you play it all back.

Another would be to get a very sturdy tripod to mount the camera on, but that may mess up your ability to record the video at such a close angle. If you have a suitable zoom which can be manually set, then this might work well without resting the camera on the scenery. If the zoom resets when the camera goes off, like many electronically controlled do, then this might not work well. My camcorder would do this when it is running on battery power as the sleep mode kicks in. If I plug it in, the camera will stay on.

Getting the background scale and focusing is going to take a little work, but it shouldn't be too difficult. If you were to find somewhere with a similar look and backdrop to what you are recording (doesn't need to be a railway, a road will do), you could record that, see how the background looks and aim to replicate that. Remember when you replicate the background to ensure that there isn't any traffic too close to the camera, for example. Any lights, shadows, smoke, etc., could look a little odd when you've covered it over with the trains.

Also, consider things such as light and clouds. If you have a patchy cloud day, then the light will change as the clouds cover and uncover the sun. With the sun in mind and the way that you are lighting the rail stock, I would keep the sun behind you when recording the background video.

[MikesMovies]

Thanks again, the back scenes was filmed from a train so I was hoping it would look ok lol.

Yes the camera sits in the middle of the model looking out to the edge, but I might try the tripod and zoom.

Out of interest here is my next try, https://youtu.be/-ZDa0OACdBA I note that the scale is off lol but it still looks pleasing

[aljimenez]

Shutter is too fast for 25fps. Use 1/25 or 1/50 to get best motion.

[MikesMovies]

Oh now that is an interesting comment, I'll certainly try it, would be most helpful on DOF issues as well.
How does this work out?

[Scubbie]

With the back drop things certainly look a lot more realistic. The view towards Gosport's town centre worked better with the light that the first view towards HMS Dolphin.

I did notice that a few times the camera for the background got knocked. I suspect it was the effets of the wind. This is where you can cheat and get away with things. Use the Mercalli Boris add-on FX and stabilise the footage. It'll blur the background footage a little, but that is perfectly fine as your focus point should be on the railway.

Edit: Also keep the transitions in sync. i.e. change both the foreground and background at the same time. It might be better to use a straight cut rather than cross-fade in some cases.

[MikesMovies]

Many thanks, do you know I totally forgot about Mercalli, rushed work stream
Yes, I am thinking the transitions don't help, added the one you see as the level of the camera changed for an as yet unknown reason and I was trying to smooth the jump.
You know the area then?

Many thanks

Mike

[Scubbie]

Many thanks, do you know I totally forgot about Mercalli, rushed work stream

That's alright. If you were to look at some of my early videos you'd rightly say that they were rubbish (or use stronger words). I'm still trying to improve things. There's a lot to learn.

Yes, I am thinking the transitions don't help, added the one you see as the level of the camera changed for an as yet unknown reason and I was trying to smooth the jump.

The result should be easy to spot in the time line as the transitions are happening at different times.

You know the area then?

You might say that

https://youtu.be/-GXiby_KA4I

[MikesMovies]

OH my word! that is stunning, have commented on the video.

Thanks for all the suggestions.

[Scubbie]

No problem. There is other local footage on my channel too .

To answer your question about the power, I was able to plug the GoPro in to the mains to keep it running over the given time period. One case I have allows me to plug in a lead and keep the GoPro protected from the elements at the same time.

I actually started recording on Wednesday afternoon. The memory card filled up early Monday morning. There was some other footage on the card which I'd recorded on Wednesday so I could get a little more if I was to do something like this on another day. The original intention was to pick up the camera on Thursday evening, but events conspired against me . It works though.

If I were to do something like this another time I may consider changing the frame rate. For this project I set the GoPro to record at one image every 2 seconds and sped it up x10 for the final video. The GoPro has options for 0.5, 1, 2, 5, 10, 30 & 60 second intervals.

I'm not keen on the fisheye effect with the GoPro. Underwater fisheye lenses allow you to benefit in other ways that you don't appreciate on land. Yes I could have corrected the fisheye with VS 2018 but it would mean that the images would have lost their quality and I would have to render it at a lower resolution.

[MikesMovies]

Shutter is too fast for 25fps. Use 1/25 or 1/50 to get best motion.

Filmed at 50fps is it better?

I personally see more blur????

https://youtu.be/A9ZJ-FGC2rI

[Scubbie]

The blur looked Ok IMHO.

You may wish to check your manual focus. Also changing the camera position doesn't help as the background is from the same perspective. This can affect how much of the scenery you pick up though, so be careful if you focus on one track and need to change it for another. Setting the aperture right and focusing on the mid-point between the two should resolve this potential issue.

Ok, perhaps I'm looking at it from a final product point of view.

It could help to cut to a completely different view, rather than stay on a similar track scene. Perhaps you could jump to a junction box or another piece of scenery? Alternatively a different shot of Portsmouth harbour, but be careful not to cross the line that you are showing and also to ensure that you don't include the area where your original footage was recorded. One idea would be to include some footage from outside the harbour, looking in. Perhaps shot near Clarence Pier? It would need to be filmed with similar weather conditions and with the sun in a similar position to work well. Also, consider any shipping movements. The easiest answer would be to not have any outside the harbour as people would wonder where they came from or where they are going.

I almost got caught when I recorded the first video with the Hovercraft that is on my channel. The intention had been to record from both angles and cut the resulting footage to make it appear as one arrival and departure. When I got home I realised that I had recorded the two different craft and that I needed to rethink the whole process.

[aljimenez]

Probably the best you can get at 25fps. To improve motion smoothness need 50fps and use 1/100 shutter