I am making a stop motion film and am concerned about flicker. I have a Canon 1000D Ef-s- 55 kit and was hoping not to have to buy a Nikon manual lens and adapter. I am looking at buying either these or these lights and using the granite bay deflicker software. I also mean to have a practical LED light on set and have read that having mixed light sources makes it near impossible to eliminate flicker. If that is so, are there any good (and cheap) LED lights out there? I live in the UK if that makes a difference.
Don Carlson said:
On my kit lens, though, I'm not sure if you would call it auto. It's set manually, and it doesn't deviate in Dragon's settings like a slide whistle.
If you set the camera on auto though, then the camera will automatically take care of focus and exposure, right? It would be pretty rare for a kit lens to be fully manual. Wait, in fact, you have a Canon, so that lens shouldn't even have an iris that you can control physically - it can only be done by the camera electronically. In fact, if I remember right, Canon lenses don't even have an iris, exposure is only taken care of inside the camera electronically (that's why you can't use Canon lenses for stopmotion - or at least you're not SUPPOSED to be able to - unless somehow Dragonframe can magically control flicker as it's apparently doing for yours Don).
It's not a manual lens if you can't operate the iris by turing the aperture ring on the lens itself - if you have to do it through the electronics then it's an automatic lens.
Another way to put it - if it wasn't an automatic lens, then Dragonframe wouldn't be able to control it electronically.
You know, that's a great point... I have no idea, then.
If we knew how Dragonframe tries to eliminate flicker then we might be able to determine why it sometimes happens and sometimes doesn't. I know nothing about it, but my first thought is that it might create a slight delay before it snaps the shot, giving the lens more time to make sure it reaches the selected f stop. That way oily iris blades slowing down the action won't be much of a factor.
But then I have no idea if this is what it does - there may be more to it or it might be something completely different. Not enough information to figure anything out. So until we learn more this one goes under the "I don't know, guess it's just magic" category and all we can say is "sometimes it works for some people, but we have no idea why or what the important factors are".
I believe there is an offset somewhere that you can change for the delay before taking the frame in Dragon. Remember seeing that and wondering what it was for.
The Dragon people would probably be a good resource for this kind of question; I'll check their boards and ask if I can't find anything.
Don wrote: I guess I'm confused about "daylight". On a bright sunny day, the sun makes everything a yellowish orange, which is the ~3000k color temperature I quoted two posts up. That color temperature is mostly seen at sunrise or sunset.
Don, direct noon-day sun is more or less 5600K, which is quite blue. That is the direct color temperature of the sun. Outside shade is VERY blue, due to the skylight scattering and acting as fill, and can easily be 15,000K. Halogen lights are 3200K, pretty much across the board, which is considered warm.
For photographers and filmmakers, much like when we pick a "timebase" for our frame rate, we "pick" a color temperature of a shot or sequence and work around it for effect. Traditionally, film was either tungsten (3200K) or daylight (5600K) balanced. Shoot under quarz halogen movie lights with tungsten balanced film and your colors would be normal. White will look white, and there won't be any color cast to your tones. Then when you go outside to shoot, you'd load up daylight balanced film and then white will photograph as white. Photograph sunlight with tungsten film stock and your scene will be overly blue. Photograph quarz lights with daylight film and they will be overly orange.
You can, of course, mix and match and use color gels or filters to correct one to the other. For example, you're shooting indoors with tungsten lights, and there's sunlight coming through a window. You'd put orange gel filter on the window (along with neutral density to bring down the light level) and then what you see outside won't have a "blue" cast to it.
Flip this around, want to shoot outside with tungsten film? No problem, just throw a blue filter on the camera lens. For decades this was a nice tidy world with just two "time bases" for color temperature, daylight and tungsten. Movie lights came in either 3200K (quarz halogen) or 5600K (HMI lightsources)
Now, enter the confusion of video cameras and DSLR's that can "white balance". All of a sudden, you can light a scene with any wacky color temperature light source, with any odd color cast or spike and force your camera to see white as white under this lighting.
That's great! Or is it?
The problem is that now you have world of very diverse lighting instruments, from LED's to Fluros, to Halogens and HMI style sources, all with unique color temperature and color casts. Therefore, picking your "time base" becomes a nightmare. Let's say you've got some odd cheap CFL bulbs from the hardware store that are actually 4700K and have a pronounced green spike to them, and you're using those as your main lightsource. You white balance to it, no problem. All's well. But then you add your quartz halogen light ('cause it's a directional spot light with barn doors) and suddenly your scene looks weird because you're mixing color temperatures and color correction. You'd have to CC your quartz light from 3200K to 4700K with some bits of 1/4 and 1/2 blue gel, then probably do some spot color correction to even out the hue. Or you orange gel your CLF's down to 3200K and throw some magenta to "minus green".
All of this can be overcome in order to take advantage of the power-saving and cooler operating characteristics of these "green" lights, but you have to know the color-temperature and the color purity of them to properly inter-mix. In regards to color purity, with the CFL's and other LED sources, check the CRI rating. Most hardware store lamps are very bad, in the 70's and 80's. Pro cinema bulbs will be 90+.
Jim...very good summation on color temperatures! I mentioned having the Alzo 85 watt CFL bulbs. I have not used them in stop motion yet. However, I did use my video camera to make a video and used those bulbs. I have attached a frame from the video. One big advantage that I see to using the CFL bulbs is 'heat'. They are a heck of a lot cooler than halogen. The reason I mention the Alzo brand is because they are color temperature rated. The CFL's that you buy at Lowe's, Home Depot, or Wal-Mart are not rated and the color temperature of those bulbs will vary.
Great explanation there, Jim!
Keith- The CFL's I get at the grocery store are color-temperature rated. It's kind of curious why others aren't. I only go for the ones that are clearly labeled.
As far as CFL's being cooler- that's the reason! On Blue Alien Summer I had really soft puppets and it was a problem (mainly in the faces). But it's been a few years, and there are techniques I've learned to deal with even the softest clay. One way is spot-freezing it with compressed air held upside down, and another is to make the head actually removable using the cap from a ball point pen an some plumber's putty for registration so that you can carefully cut or peel off the entire mouth area, ball it up in your fingers, and re-sculpt the lip flaps with the same clay or another ball of the same amount. This will help to keep your puppet proportions "on model". Just make sure that if the inner mouth area is black, to have it extend all the way down to the chin if you intend to move the mouth down for comical effect.
Here's a test from yesterday using CFL's and displacement modeling on a replaceable head. The flicker at the beginning is a bumped light which still needs to be tacked down. I had reached for a ball of clay too close to the light's cord...A rookie mistake!
Sorry Don, I replied having not read the 2nd and 3rd pages of posts, still not used to the new forum, so my response may have sounded a little lost in limbo.
I just did a quick Google to find "acceptable" CFL's... always buy units that have both the color temperature AND the CRI listed for them... these are good, and available in both 3200K and 5600K
(Though I'd bet some money that they're NOT exactly 3200 or 5600 but fairly close)
A couple other notes;
-First, CFL's are inherently soft lights and can't cast pin-sharp shadows or "throw" light a long ways... there is still need for that in lighting. Not all films happen in the shade of a building, or on over-cast days! LED tech holds promise for units that can deliver this sort of light, but the halogen fresnel units with barn doors are still the best bang for buck.
-Your color temperature pre-sets on digital cameras ASSUMES that the CRI is perfect, and of course, it's not in practice perfect. There is a difference between manually white-balancing and simply choosing a pre-set. An example: you choose the "tungsten" pre-set and use a correct quartz halogen fresnel light, but it's attached to 100' of power cord and the light is actually putting out 3000K... your image will be a bit warm/orange. But manually white-balance (or auto white balance but we don't auto anything in stop/mo!) and it will appear correct.. the manual white balance will account for the color shift.
-Finally, the perceived visual difference between a couple hundred degrees of color temperature is great on the low end, but less so on the higher end. Example, 2900K (standard light bulb) is very orange compared to a proper 3200K movie light. But that same 300K difference would be less detectable up in the 5600-6000K range.
I agree that CFL's can not do strong, harsh and direct lighting. That's the only disadvantage I've found in using them. But for some reason (possibly mental illness) I like to have my lights close to the set. Actually, the real reason is that there's not a lot of room outside the set for lights. There's a light, and then the wall angles out from a 3 feet recess, and then the bed. Total working space is about 8 feet x 8 feet by 4 feet, and moving the light stands from the set blocks access to where I store backgrounds and stage platforms. Because the stage has a ceiling, it also gets in the way of the light if I move them any farther than 2 feet from the puppets. If I had a bigger room, I would probably go with halogen fresnels and hang them on a grid and place them so far from the set that they couldn't soften the clay.
What are you guys using for spot lights?
I'm using halogen PAR 20's (just the bulb) in combination with an aluminum bell fixture on a cheap hardware clamp light. Curious what happens when you use a narrower bell, does the light get brigher and more focused?
I have yet to take the bell thing off and just use the light bulb, so I'm not sure if the intense spot effect I'm getting is from the light itself or the housing it's in- but it's much brighter than my PAR 30 disco pin spot, which used to overpower all of my other lighting.
It turns out that I could use one halogen without getting the clay too soft, and I also found ways to deal with soft clay so the hot lights are not as much of an issue. In fact, I can actually reshape a puppet's face faster if the clay is somewhat warm.
I don't think the housing makes much difference to the actual beam itself, though a longer narrower snoot would eliminate much of the spill light, and of course barn doors could be used to shape the beam better. But with the PAR lights the main shaping of the beam is done by the parabolic aluminized reflector (that's where the name comes from - it's an acronym) - so the lamp (the 'bulb') is the entire unit really. You can buy them in spot (narrow), medium, or flood (wide) beam and in various wattages for different illumination levels. You can find a good selection through the Premiere Lighting website. Here's their page featuring PAR can lighting units and bulbs: http://www.premier-lighting.com/shop/pars.html
The ones I'm talking about are listed under the sections PAR 20 & 16 and just above it, where it says PAR cans (I don't buy my larger PARs from Premiere though, I have a cheaper source through Musician's Friend). Those are the basic inexpensive ones - the rest of them on that page are specialty units with fancy electronic features made for use in discos and stage shows that we don't need. The 16s and 20s make nice small spotlights, while the 46, 56 and 64 will cover half or more of your table.
I can't find the site anymore where I (finally) found barn doors for the PAR 16s, but here's another site I just turned up that actually looks identical but with a different name/logo: http://www.musson.com/par-16-barndoor-four-leaf.html
And for really tight spots I use the Solux Framing Art Light. Here's some info on my blog about that: http://darkmattr.blogspot.com/search/label/framing%20projector