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 Post subject: Newbie with questions!
PostPosted: Wed Jul 18, 2012 12:13 am 
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Evening all,

I'm Jim and I've just located this forum, and i hope you good people can be of much assistance.

I'm very new to video and visuals, my background has primarily been audio, both in term of performance and production, but recently I've begun dabbling in (very) amateur film making, and I have a few things I'd really appreciate if you could help me out with.

As I said, music was my big thing previously, so it seemed to make sense that my initial foray into visuals should be directing DIY music video for my friends band. I had a first go at this late last year, and it was totally a test the water type effort - I had one cheap camera and I set up multiple takes of the band lip-syncing to their song in their fairly small rehearsal room. I set up a four click count in for the audio so the band knew exactly where to come in, and so I could sync up the visuals with the audio. I believe I managed about 6 takes in total, the room being somewhat constrained I struggled to get one take where all four musicians were in shot, so I mixed between focusing between smaller areas and built up just about enough angles to give me something workable. I was limited to using just the poor lighting within the room itself. Naturally the results were pretty much as poor as we all expected, although there were some nice cuts here and there, it was purely a test piece and a learning experience.

So, now to project number two, a second video for the same band, and naturally we're looking at getting the finished results up to the next level. We're going for something much more ambitious, in addition to a performance part of the video there will be some additional parts done with a green screen and some intercut footage that we'll be filming further down the line, but the most challenging part, and the bit I'm going to be asking you good people for help with here is purely the performance footage. I have some queries about lights and lighting, a few on the camera setup, and some queries on the actual filming - sorry if this turns into an epic post!

1) Lights - for this shoot I knew I wanted some form of proper lighting. As you've probably gathered, I'm on a very limited budget so purchasing dedicated film/photography lights was a financial no-no, so I've followed the device I've found a few DIY film-maker sites and purchased halogen floodlights from a hardware store. These are they;

I've got two of these - http://www.machinemart.co.uk/shop/product/details/chl150-wall-mounted-150w-floodlight

And one of these - http://www.machinemart.co.uk/shop/product/details/chl500d-halogen-floodlight-500w230v

I would have gone for three 150w lights but I bought the last two in stock and wanted the third for a basic three point lighting setup. What are your thoughts on these? I know they are not ideal, but they are great price, they can be mounted onto stands very easily, they seem to give a lot of bang for the buck.

However, my main query regarding these lights is a more basic, electrical one. The lights do not come supplied with a cable to connect them to the mains, I wanted some advice regarding the specs that the instructions suggested. The instructions suggest using 13amp fuses, and three-core cable with a conductor width of 1.5mm. At first I thought I'd be clever and just cannibalise my old electrical extension cable, however it appears that it only has a conductor width of 1.25mm. Rather annoyingly I find 1.5mm cable is not common around the home, and its a little on the steep side in terms of purchase, I've not found it for less than £1.40 per metre. At this point another thing struck me - I had originally planned to have long cables (at least 5 metres for each light) thanks to the abundance of cable in my old extension lead, however, if I had to purchase 1.5mm cable then I didn't think I could afford that much of it, probably only 2 metres maximum per light. I realised that this probably would not be enough for the cables to reach the wall socket in the location we're hoping to film, so I'd be looking having to use extensions and surge protected 4 gang adaptors, etc. To my horror I realised that if my light cables had to be 1.5mm conductor width, then probably so to would my extension cables have to be, would they not?

I then decided to investigate further the need for 1.5mm conductor width. I've noted that most sources of information suggest that for up to 13amp appliances, 1.25mm cable ought to be sufficient. 1.5mm is usually used in conjunction with 15amp appliances and so seemed a bit overkill. However, I know the implications of getting this wrong could result in the cables melting and a serious electrical fire, I want to work on a shoestring budget, but I'm not a careless fool! :lol: What do you guys think. I'm hoping the lights would be safe on the thinner cable for short durations, if I were sensible about this and say switched them off to cool down between takes, could I negate the risk a little? Ultimately I think I will buy long 1.5mm cables, but this could take a while to fully cable all three lights.

2) Lighting of the shoot - assuming I get the lights working, how does one set up three point lighting for a shoot like this? The band are a four piece combo and we're looking at filming in a location at least 6x10 metres. I do envisage there being some longer shots where the whole band are visible so I was thinking that the 500w and one of the 150w lights ought to be my key and fill lights at the far end of the room from the band, probably pointed more towards the side walls for a bit of diffusion, and the remaining 150w light maybe suspended on a boom near the back end of the room? My problem with this is that I expect the singer/guitarist, lead guitarist and bassist to line up together, with the drummer just behind them, so where exactly should I put my back light - shining down behind the front three musicians but in front of the drummer, or shining down behind the whole band? I think the later would be best but I'm worried about the drummer getting the brunt of the background light and getting roasted alive in the heat! Any suggestions?

3) Cameras - I've got four cameras at my disposal for this shoot, unfortunately they're of differing quality. My main camera is going to me my wifes new Fujifilm Finepix HS30 EXR - I know its not a DSLR but its a decent bridging alternative, and frnakly the best camera at my disposal at present. I would like to use this for all the important shots, and use a mix of tripod and steady cam angles. I've also got my wifes older Fujifilm Finepix S5800, a more basic bridging cam but a solid 2nd camera. I've still got my Sanyo Xacti camcorder, which was used in my previous shoot - its cheap and cheerful but its alright, and finally the singer from the band has one of those incredible cheap Vivitar cameras - this one in fact - http://www.vivitar.com/products/2/digital-video-recorders/423/dvr-925hd.

The plan is that for each take I'll be getting the most important shots with the main camera, while the other three will be dotted around on tripods getting stock footage for cutaways and filling gaps, etc.

However, all of these cameras have different resolutions, the main camera can do 1920×1080, the other Fujifilm can only do a max of 640x480 pixels, and the other two camcorders are somewhere in between. What should I do here, use each camera to the highest resolution it has - I'd have thought this might provide inconsistent quality. I know three of the cameras can do 1280 x 720, so should I just use those three at that resolution in an attempt to get a basic standard and drop the second Fujifilm altogether?

Well, I think that enough rambling for now, any guidance you can give would be really appreciated.

many thanks

Jim

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PostPosted: Wed Jul 18, 2012 7:11 am 
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Hi Jim and welcome,

Your post covers a lot of ground, so rather than attempt to answer it all I'll just give you my immediate opinions.

Others here know far more about lighting than me and will no doubt have much to say, but I wouldn't get too bogged down with 3 point lighting. My understanding is it is appropriate for lighting a simgle person, but lighting a "scene" as you will be, is somewhat different. However, it is still useful to bear it in mind as it will remind you to focus on where the main light is coming from, where the fills are coming from and separating the subject from the background.

As far as the camera is concerned, unless there is really stuff which cannot be repeated (like real-time special effects) shoot it all with the one camera. Trying to match the different colours and resolutions in post will be extremely time consuming and frustrating and is unlikely to give results you'll be happty with. Just shoot the same "scene" several times from different angles.

Finally, you are probably aware of this, but don't let the talent mime. Get them to sing out loud - miming never looks as authentic as if they are really singing.

Good luck and I hope you enjoy your new found hobby.

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Proud to be an amateur film maker - I do it for the love of it


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PostPosted: Wed Jul 18, 2012 10:47 am 
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Jim, that's a LOT of questions.

If you're out to make DVDs rather than Blu-rays then setting each camera to its highest recording resolution is the way to go. The 720 x 576 DVD will somewhat equalise all the different camcorder settings, though the auto white balance differences may be harder to take. Yes, I'd drop the 640x480 camera but then again, if it's better in low light than the Vivitar (and what camera isn't) then its footage may look ok on the DVD. All your cameras shoot native 16:9? You won't be wanting to shoot 4:3 music videos, will you?

But you've got to start somewhere, and joining this forum is a good place to be - there's a wealth of info here.

tom.


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PostPosted: Wed Jul 18, 2012 3:40 pm 
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Hello

Thanks to Tim and Tom for your initial responses, thats pretty helpful.

The main reason for using multiple cameras is time constraints, last time I managed about 6 usable takes in about 5 hours with a single camera, and it was nowhere near enough, I was hoping to cover more angles in the same amount of time.

Oh dear, more woes with cameras, it turns out that my Xacti camcorder is model vpc-cg9ex which only goes up to 640 x 480 as well.

Well, this video is still an early experiment and frankly other than appearing on You Tube and being embedded on the bands website, I've not exactly got cinematic plans for it!

Anyway, aspect ratio, I'd hazard a guess that only the main camera and possibly the maligned Vivitar camera are the only ones to shoot natively in 16.9. I've seen some very basic and often confusing tutorials about manually changing the aspect ratio in the editing software, from what I can gather they involve still saving the final video in 4:3 but cropping the top and bottom of the footage to add the black bars giving a widescreen look.Not sure how one does this with any sort of precision, presumably you guys would say this is a another reason to purely use the main camera on its own. For You Tube efforts, is the aspect ratio that important?

Finally, anyone got any ideas regarding the light electrical cables?

Jim

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PostPosted: Fri Jul 20, 2012 4:40 pm 
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JIm,

I am assuming you have measured your old extension lead cable correctly (the measurements are the diameters of the conductors and not the conductors plus the red and black plastic insulation around them.

This being the case then we can first use Ohms law to work out the current flow for your 150 and 500 Watt lamps.
I = W/V, so 150 W/220 V = 0.68 Amps for the 150 Watt lamps, and 500 W/220 V = 2.27 Amps for the 500Watt lamp.

Now we need to convert your 'metric' conductor diameter of 1.25mm into a wire guage size. I will use AWG (American Wire Guage), as this will allow us to check against the NWPA table of Maximum Overcurrent for Wire Guages.
1.25mm (0.049") = 16 AWG. (And 1.5mm (0.059") = 15 AWG).
The table shows us that 16 AWG has a maximum recommended current draw of 10 Amps. (And 15 AWG is good for 13 Amps).

So we can conclude that your old (1.25mm Conductor) cable will be well within the max current draw limit, when feeding both the 150 Watt and the 500 Watt lamps. Indeed, you could also use it to feed all three lamps at the same time, as the combined current draw would only be 3.63 Amps.

Hope this helps,

Kind regards,
Fred.

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PostPosted: Fri Jul 20, 2012 7:48 pm 
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Thank you Fred D,

Glad to have it confirmed. I'd also been posting on a dedicated electrical forum and they have just produced a similar answer, although not as detailed an explanation.

Many thanks, I shall begin hacking up my old extension cable forthwith!

Jim

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PostPosted: Sat Jul 21, 2012 1:05 am 
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This is my third try at posting this message in three days. I asked a friend who is an expert in electrics and electronics for advice:
Here is is reply.

OK. Firstly it is not conductor width but cross sectional area in sq mm. A 150 W lamp takes 0.625 Amp and a 500W lamp 2.08 Amps while running. However the start up current is very much higher and only drops to the above figures when the filament is up to temperature. Thus a fuse rating larger than the above figures has to be used in order to prevent nuisance blowing at switch-on.

Whatever fuse is used, the cable rating must equal or exceed it. A 13 A fuse needs a minimum of 1.0 sq mm cable (rated 14A). However, the mechanical protection of the cable is important too so I would go for the standard 1.5 sq mm. If low tempretures are expected, then arctic cable remains flexible down to -20 C.

Because of the temperature inside the lamp, the individual wires inside the lamp must have fibreglass high temp sleeving in the recommended colours slipped over them.

TLC sell 1.5 sq mm (code CA1.5F3) for £0.90/m or £28.50 for 50m (£0.57/m) +VAT. The arctic (code CA 1.5 ART3) is £0.88/m or £31 for 50m +VAT

Electrical safety should never be compromised by using electrically undersize or mechanically weak cable, it is too dangerous and you could be liable for enormous damages if anyone is injured by your faulty design or work.

The last point is one to keep very much in mind.

And thanks Fred D for pointing out I had put it in the wrong forum last night. (It's the drugs!) I have removed it from the wrong place now. - Dopey Dave


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PostPosted: Sat Jul 21, 2012 11:13 am 
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Just to add, as conductor 'cross sectional area' has been brought up, and to avoid any confusion :

The cross sectional area of a 1.25mm diameter conductor can be calculated using the formula 'Pi X r squared'
Thus : 3.142 X 0.625sqd = 1.227 sq mm.

As you can see, this figure is well above the 1.0 sq mm / 14 Amp 'standard' suggested by Daves
'expert' friend.

Kind regards,
Fred D (retired Electrical engineer)

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PostPosted: Sat Jul 21, 2012 11:32 am 
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Hi Fred and Dave

Thanks for your replies, can I paraphrase a bit here as there is a lot to take in...

Fred seems to suggest that the old 1.25 cable should be fine, but Dave's mate suggests that 1.5 is probably better. As the cable will be used indoors at room temperature, I think I'm alright there with my 1.25 cable.

Fuse - although most evidence suggests 3 amps ought to be fine, the instructions with the lamps suggest using 13amps and Dave's friend backs this up suggesting that the initial startup current will be higher, so 13amps should ensure that the fuses don't blow while the lights are reaching optimum temperature.

Dave's friend states, 'Because of the temperature inside the lamp, the individual wires inside the lamp must have fibreglass high temp sleeving in the recommended colours slipped over them.'

What is fibreglass high temp sleeving, its a new one on me. I googled it, but I'm if I'm looking at the right stuff. Are you talking about somehow fitting this to the 3 wires inside the cable or over the cable itself? :?

thanks

Jim

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PostPosted: Sat Jul 21, 2012 2:45 pm 
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Yes, things get complicated quickly in this area.

1.25 cable will work but be gentle with it. The concern is not so much the current carrying capacity of that cable but its physical strength. Don't let the band play tug-o-war with it! Seriously: always try to place cables where they are not subjected to stress or physical damage. That includes making sure no one will trip over them which may hurt the cable a little but will hurt the faller a lot more.

13amp fuse recommended.

The sleeving is only needed within the lamp housings themselves. It is likely that the lamps come with an electrical lead already fitted which you will be plugging into your extension wire. If that is so, then the sleeves should already be fitted inside them. So relax.

(The sleeves are heat-protection and usually within a lamp-housing the cable is opened up so that the three wires inside - positive, negative and earth - can be routed to the proper terminals. It is over those three wires that you need three sleeves.)

On the practical side of things: in a music video you can get away with some murkiness. People think it is atmospheric and resembles the lighting in a lot of small clubs. Ideally try to do one take of the whole number with the lead singer/soloist as well lit as you can get them. If one camera shoots that close-up and another shoots it from a different angle and wide enough to include the whole band ... you will have those as safety shots to cut to whenever you need them.

If time permits doing the same thing with each band member in turn is tactful, but you can often get away with showing the rhythm section as a group and the backing singers/musicians as a group.

Then try some shots with "interesting" lighting - such as all from one side or all behind the band ... anything to look dramatic and artie.

Remember the great fall-back is to do some shots at another time with one or two band members outside jumping walls, driving motor-bikes, helping little old ladies across the road ... depending on the nature of the songs. You can cut those in to the "stage" shots like little flashbacks.

Have fun, Dave


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PostPosted: Sun Jul 29, 2012 9:21 pm 
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Many thanks to Dave and Fred for your vital, and possibly life saving advice! I have now purchased the correct spec cable (Dave - good call on TLC as a supplier - would you believe they actually have an outlet about 10 minutes walk from where I live, bonus!) I have now tested my 150W lights and will be testing the 500W light shortly.

Now I'm actually up and running with my project I thought I'd start a blog to document how it goes. I guess its partly to record what happens kind of like a journal, but also I'm hoping it'll act as a beginners guide to other people considering having a go at amateur filmmaking - hopefully pointing out the various perils and pitfalls (probably as I fall headlong into them!) and also a bit of an inspiration to get them out there trying it themselves.

Anyway, if you want to have a look at how I'm getting on, its available here;

http://mysticjim.blogspot.co.uk/

Obviously, if you know anyone who might benefit from it, please feel free to send them my way!

Well, hopefully I'll be posting on here next with a completed video to show you, although I'm sure its more likely that I'll be back asking for advice on how to deal with my next technical crisis first, but I will get there in the end!

cheers and many thanks for all your help

Jim

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PostPosted: Thu Aug 09, 2012 10:34 am 
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Nice blog jim ...keep up the good work

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PostPosted: Sun Aug 12, 2012 7:57 pm 
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Hi John

Thanks for checking out the blog, hopefully - by this time next week I will have some actual filming done to report back on, then things will start in earnest.

In the meantime, though, I've also got a podcast running in conjunction with the blog, this is much more the general movie review and discussion, although I will mention some of the filming exploits I get to up as well.

You're very welcome to check it out.

Many thanks

Jim

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