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?

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.

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.

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

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!

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

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

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.

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?

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.

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?

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.

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

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

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/wireless_video_sender_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.

I've shot my mini35 with Cooke, Zeiss T1.2 high speed primes and never once recorded vignetting images on my XL1 or XL2.

If your going to use the mini35 for a shoot I strongly recommend working with someone who has mini35 experience or at the very least try and arrange a test shoot with the renting house. This is the only way to truly know what you are going to get and will certianly avoid any surprises on the day of your shoot.

The mini35 is a truly remarkable device but it's not without it's unique set of "nuances" if I can call them that.

Some mini35 tips:

Proably very key is setting the back focus on the mini35. Just a slight (and I mean VERY slight) twist of the back focus ring causes minute adjustments to the focusing on the mini35 screen. It is very handy to use a resolution chart and large monitor to set the initial calibration and focus of your mini35.

Set the camera for -3dB or 0dB for best image with lowest amount of noise present.

If possible AVOID shooting wide open (ie. f1.2). Although the mini35 adds approximately 2 stops of loss to the equation you will find it very difficult to follow focusing with such extreme low f-stops. Shooting with higher f-stops, say f4 on your lens gives you a little more flexibility by increasing your overall depth of field from fractions of inches to several inches.

Don't forget to turn your motor on. If possible leave it on all the time - it is better to waste batteries then to forget to turn it on. Sometimes with the pressures involved during shooting it is easy for someone to forget to turn it on.

I like to keep a can of compressed air to blow dust off both ends of the lenses before attaching to the mini35. As well as slik cloth to remove any greasy finger prints that sometimes develop from handling the lens.

Use an external monitor if possible while shooting to really see the image you are getting. Not everything can be fixed in post ; )

Have fun with it and don't forget to post your work or results on such popular forums such as dvinfo.net.

Thank for all your input and tips Dennis!

I've rented the Mini35 for two weeks, when shooting three days so I have some time for trial and errors!

When do you start shooting?

Please post some frame grabs or a website where they can be viewed.

By the way, since Switzerland is PAL signal what frame rate do you intend on shooting your film in?

Hi Dennis,

I also have a video sender, but mine is mains powered.

How did you go about converting your to run off batteries?

Thanks.

Hi all!

Thanks to you Dennis i bought a similar transmitter. Works fine, mine is powered through an electric adapter (9 volts DC) so it should be an easy task to replace with a battery!

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!

I own the Mini35, and its safe to say you lose 2stops easy, so make sure you compensate. PLEASE do yourself a favor and have at least a 23" monitor on set at ALL Times, or you may run into post problems with Mini35 accidentally off or focus problems. Trust me, you don't want that.

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.

Dennis,

Why not use Mini35 for slowmotion? I am shooting 60P HD with the new HD200/250 soon and a lot of action sequences will be slowmo 60P slowed down to 24p in post. Whats the issue as you see it, if any?

What do you think of a shutter speed like 1/120? I read in some paper from P+S Pro35, their recommendation for slower shutter speeds, as fast shutter speeds may cause artifakts. I'm planning to do an overcrank slow motion when I will need a slightly faster shutter (workflow: fast shutter in 50i, convert to 720p60 and then slow down the speed in cinema tools). What is the optimal shutterspeed for Mini35 and 25p? Is it possible to mix and match footage from the Mini35 with regular shots with stock lens?

I have seen this post sitting unanswered so here's my bit in the meantime until someone wiser comes along. I am not a practiced Mini35 user so don't pay too much heed to my following comments.

1/120 sec shutter speed may be a bit fast. The only real way to know is to shoot test footage.

I think you have a fairly good chance of succeeding with it in the camera but the conversion to 720P 60 and the other post-processing may give you some problems than any frozen groundglass grains may.

Things that I think may help you.

Try to avoid strong outdoors contrasts and shooting against the sun. Give the Mini35 plenty of light. Try to avoid broad strongly lit out of focus or plain surfaces in the image such as sky or plain painted walls. If there are any artifacts, they will be less evident if buried in a darker or textured background.

If you do get artifacts, there is a method for replicating the motion signature of film published here at dvinfo. It involves Adobe After Effects, interpreting footage, importing two copies of the same clip, selecting upper field for one and lower field for another plus some other stuff. too detailed to describe here.

Blend the two fields and maybe some of the artifacting can be made to go away.

I imagine however that this process and your post-production slow-motion method may conflict. It might be possible to render out the motion signature altered footage as interlaced, then try again from that.

Otherwise, after creating your slow-motion effect, if there is significant groundglass artifacting or frozen grains, maybe lay on a timeline four copies of the same clip, each of 25% transparency, each clip slipped back one frame relative to the one under it, so clip four is four frames behind clip one.

This has the effect of reducing the intensity of an individual grain mark by 75% but introduces more of them. It works fairly well with video gain noise.

The motion will tend to create smeary trails but the grain artifacts may become less evident. I think in After Effects, there is a process called frame blending which might amount to the same thing.

There was a method described some time back for masking out fixed artifacts of fixed groundglass relay devices. I have forgetten just where it was and who published it. A search under ALDU35 might pick it up.