Slow Motion with Mini35

[Jonas Nystrom]

I'm doing a job with a rented Mini35 and my XL H1. I want to do some slow motions - is it possible? The risk to recognice some grain should be greater, or? What presets should I have and what should I have in mind?

[Dan Keaton]

I would start with the following:

Use 1080i60 or 1080i50 (I do not know what is available on your XL H1.

Then use a shutter speed of 1/120th (if in 1080i60) or 1/100th (if in 1080i50).

I have created slow motion using Vegas Velocity Envelope at 1% or normal speed and it worked amazingly well. Technically, I should use 1.66% but 1% was the slowest available, and the next was 2%.

My original footage was taken at 1080i60 with a shutter speed of 1/60th. I later learned from this site that 1/120th or 1/100th should yield better results.

I do not know how this will work with your Mini35, but I think it will be worth a test.

[Bob Hart]

If the XLH1 can do what the others can, I think the Mini35 will be able to cope with it. You may need to start by running the groundglass at maximum then maybe ramp it down a lttle while watching a monitor to see if any artifacts which may turn up can be made less evident.

You might need to make sure the lens on front is closer to wide-open, to ensure there is plenty of light on the groundglass to wash out any artifacts and try to avoid situations which combine high contrast and strong light coming from in front of the camera like shooting against a three o'clock sun.

On a home-made adaptor with a Sony FX1, I have shot 1/100 sec through carelessness and not noticed any problem except for the more evident judder (loss of motion blur). The Mini35 I have had a chance to play with, seems to be more forgiving than my own gadget.

If luck and skill does not prevail, there is another desperate measure you can try which will have a slight softening effect on you images which you might have to add grain to in post to create the illusion of sharpness.

That desperate measure is to set the relay focus slightly off sharpness. If you use 60% zebras while setting relay focus accvording to the P+S method, then set the relay iris so that the zebra lines show partially across an image of sky close to horizon where there is a variation of intensity, you will observe that the zebra pattern covers a widest area when the relay is sharpest. With practice, you can use this effect to minutely de-sharpen the relayed image to slightly reduce visible groundglass texture. This is to adjust the relay to slightly reduce the area of the zebra patch so that any little random flickering spots on the zebra patch edges disappear.

I am not an industry professional so do not bet your career on my suggestions.

[Jonas Nystrom]

OK I try. Thanks for your input! Best /J

[Jonas Nystrom]

Another Question; does the Mini35 need lot's of light? For the moment in Sweden, it is a kind of massive darkness, and I trying to see how much light I will need. I'm looking for a short DOF of course!

[Djee Smit]

they say you lose about 1 stop light using the adapter, so you probably have to compensate that with some extra lighting.

[Bob Hart]

The following table on the P+S Technik Pro35, came to me via a convoluted route.

The original attribution for the table is to Clairmont Camera in Hollywood and Peter Gray, a DP wrote the web article, which I have a mutilated copy of.


CINE LENS STOP LIGHT LOSS LIGHTING LEVEL

T1.9 -1&2/3 STOPS needs T3.5
T2.0 -1&2/3 STOPS needs T3.6
T2.8 -1&1/3 STOPS needs T4.5
T4.0 -1 STOP needs T5.6
T5.6 -2/3 STOP needs T7.2
T8.0 -1/3 STOP needs T9.0
T11 -1/3 STOP needs T12.7
T16 NONE same T16
T22 NONE same T22

[Dennis Hingsberg]

Shooting with the mini35 is like shooting 60ASA where sun light is your friend, and moon light is your enemy. For night scenes you need light or your image will be very black.

For your slow motion clip consider not using the mini35 for that scene unless you really need the DOF of course. Then you may not have much choice.

If I needed a great slo-mo clip using the min35 I'd be inclinded to use something like the Twixster plug-in for AE to create "missing" frame fields. I might then use another plug-in to insert grain to the "new" fields so that even the grain effect is animated at 60i again. (ie. instead of being animated at 30fps).

Hope this helps.

[Jonas Nystrom]

Thanks again all, for your input! How to count focal length compared with 1/3 chip camera? Is the Mini35 equalent with a 1/3 chip?

[Bob Hart]

How to count focal length compared with 1/3 chip camera? Is the Mini35 equalent with a 1/3 chip?


My rough and ready method.


For 35mm motion picture frame

Lens Focal Length in mm divided by 24mm (22mm for Mini35). = ???


For 1/3"CCD ( 8mm )

Lens Focal Length in mm divided by 8mm = ????


Example.

Movie - 50mm divided by 24mm = 2 approximately.

Videocam - 8mm multiplied by 2 = 16mm

So approximate equivalence is roughly :-

For field of view of 50mm movie lens, the video camera uses 16mm lens or zoom setting.

I failed math from year five onwards so don't bet your life on these numbers or the method.

[Jonas Nystrom]

Thank you all, again.

I've been in contact with two "rent house". One of highly recomend a Cooke zoom starting @ 3. The other house say they don't recomend zooms to the mini35. They say you should use high speeds primes - What do you say guys?

[Dennis Hingsberg]

Jonas - They probably don't recommend zooms because likely the zooms they rent are not fast and they know under some shooting situations slow lenses with the mini35 will not produce satisfactory results for renters.

However a T3 zoom will be MORE than adequate for outdoor daylight shots, in fact expect to use additional Neutral Density filters to lower incoming light. You'll need to block at least a few additional stops.

Unfortunately for indoor shooting, T3 may very well be too slow. I've worked with the mini35 indoors using T1.2 lenses for indoor night scenes and lighting it was extremely challenging to say the least. In some cases you must increase the gain of the Canon from 0dB to +6dB or higher and doing this will add some noise to your image. You can sometimes clean this a little in post but still it is noise that is better to avoid if possible.

[Jonas Nystrom]

OK, I red somewhere that you could receive vignetting with wide high speed primes. Do you heard or experienced?

[Jonas Nystrom]

(little) of topic - Dennis which Wireless Video sender do you use (saw at your site)

[Dennis Hingsberg]

Jonas,

I use a very cheap 2.4GHz video transmitter/receiver system which I've modified to run off external batteries. Believe it or not, it works REALLY well for $50. I'm of course using it to transmit SD though not HD.

Check it out: http://www.x10.com/promotions/wirele...der_vk80a.html

However the one I bought at the time included a modulated RF output on the receiver which made it easier to hook up to almost any TV or monitor.