Slow Motion with Mini35

Dennis Hingsberg · December 17th, 2006, 04:37 PM

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.

Jonas Nystrom · December 17th, 2006, 04:53 PM

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!

Dennis Hingsberg · December 17th, 2006, 06:12 PM

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?

Antony Meadley · December 29th, 2006, 06:37 AM

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.

Jonas Nystrom · December 29th, 2006, 08:03 AM

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!

Brian Duke · December 30th, 2006, 06:05 PM

Quote:

Originally Posted by 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!

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.

Brian Duke · December 30th, 2006, 06:10 PM

Quote:

Originally Posted by Dennis Hingsberg

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?

Jonas Nystrom · January 20th, 2007, 10:55 AM

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?

Bob Hart · January 23rd, 2007, 10:15 AM

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.

December 17th, 2006, 04:37 PM	#16
Dennis Hingsberg Trustee Join Date: Oct 2003 Location: Toronto, Canada Posts: 1,055	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. __________________ Blog: www.hingsberg.com Ultimate Exposure Guides for FS5/F7S/F5/F55

December 17th, 2006, 04:53 PM	#17
Jonas Nystrom Major Player Join Date: Jan 2006 Location: Göteborg, Sweden Posts: 306	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! __________________ Jonas Nyström, DoP :: HOT SHOT® SWEDEN :: www.hotshot.nu :: RED #1567, RED 18-50mm T3 :: XL A1, Letus Extreme :: XL H1, 20X & 6X lens (for sale) :: www.vimeo.com/nystrom

December 17th, 2006, 06:12 PM	#18
Dennis Hingsberg Trustee Join Date: Oct 2003 Location: Toronto, Canada Posts: 1,055	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? __________________ Blog: www.hingsberg.com Ultimate Exposure Guides for FS5/F7S/F5/F55

December 29th, 2006, 06:37 AM	#19
Antony Meadley New Boot Join Date: May 2005 Posts: 14	Video Sender 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.

December 29th, 2006, 08:03 AM	#20
Jonas Nystrom Major Player Join Date: Jan 2006 Location: Göteborg, Sweden Posts: 306	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! __________________ Jonas Nyström, DoP :: HOT SHOT® SWEDEN :: www.hotshot.nu :: RED #1567, RED 18-50mm T3 :: XL A1, Letus Extreme :: XL H1, 20X & 6X lens (for sale) :: www.vimeo.com/nystrom

January 20th, 2007, 10:55 AM	#23
Jonas Nystrom Major Player Join Date: Jan 2006 Location: Göteborg, Sweden Posts: 306	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? __________________ Jonas Nyström, DoP :: HOT SHOT® SWEDEN :: www.hotshot.nu :: RED #1567, RED 18-50mm T3 :: XL A1, Letus Extreme :: XL H1, 20X & 6X lens (for sale) :: www.vimeo.com/nystrom

January 23rd, 2007, 10:15 AM	#24
Bob Hart Inner Circle Join Date: Dec 2003 Location: PERTH. W.A. AUSTRALIA. Posts: 4,477	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.