Victor:
Yes, what T Stop you're shooting at is very important. I mostly keep my lenses wide open at T1.4 and have no trouble at all.

<<If you don't have the motor on and you pan or tilt, you'll see grain, with any focal length. I NEVER shut the motor off, because of the noticeable grain in the ground glass. It's like shooting through a dirty lens.
>>

Honestly, I don't see his in shots with proper exposure, and shorter focal lengths. In fact I just finished about 2 hours of footage testing the limits of the grain with pans and tilts at different exposures, motor: on, slow and fast using 35mm 1.4, 50mm 1.2, 85mm 1.4 and I was able to shoot with no motor in a number of configurations. YMMV

Wow, really. I haven't experienced that. If you can somehow write up your results with images or video that would be cool.

I have always seen the grain in any one of my lenses with the motor off when panning or tilting. Of course "proper exposure" is in question. Though I would say the shots I've seen it in are properly exposed. Slow and fast doesn't seem to make that much of a difference. When the motor is OFF is when I see the difference.

For the record I've shot more than 50 hours of footage with my mini 35 in the last month. 2 shorts and 1 feature still in production. Some of these things you can see in the field, it is when you look at them on the computer or projected is when you really start to see them. Though I've begun to notice it in the viewfinder. Probably because my eye is tuned to it.

I'll try and do some strict comparison tests, when I have some free time. That'll be in September.

Jim,
excuse me but what do you mean here with proper exposed? Properly exposed for the limits of the device (keeping totaly open the frontal lens) or proparly exposed for what the image we want to photograph requests?

What I need is the flexibility to close down the iris till F5.6 without getting probelms with the ground-glass, rotating or not rotating. Right now I start to see the glass rotating in the center (!!!) around F 2.8 1/3.

Also can I not understand why panning or tilting could have any effects on seeing the grain. The grain is on the glass and the lenses of the mini35 are focused constantly on that plane. The only way I see could be to reduce the back-focus, something I definitly would not love to do.

Question, what model do you have? I have one of the later ones, which is revision 2002. I know they made some changes to the last years models, but I don't know what.
Istvan

Properly exposed images are somewhat subjective.

Seeing grain when panning or tilting is only an issue when the spinning glass is NOT on.

I have the 2002 model. They've made one change that I know of to this model. The motor switch is horizontal rather than vertical.

We didn't have the luxury of a real external monitor. We used a 5-inch LCD monitor. This was a big mistake, because we forgot to turn on the spinning feature during an important shot. Using the 40mm lens stopped at 2, we can still see the grain, which looks like dust on the lens. It was a panning shot, so the grain is even more obvious. However, only myself and my DP noticed this when reviewing the rush. Most people didn't notice it.

Another reason to use a real monitor is that the exposure and color are difficult to judge with the viewfinder and an LCD monitor. The color in the viewfinder was very cold, almost blueish.

Basically from testing during pre-production (with a studio monitor), we decided to ALWAYS leave the Mini 35 spinning on high (the on/off switch at the back being horizontal). There's no reason not to. Even battery drain is minimal. Spinning the Mini 35 on high always produced the sharpest images.

We kept all the lenses stopped at 2. However, we played a lot with that "iris" that works like an adjustable ND filter.


<<<-- Originally posted by stevettt :
Just two more questions:
- do you controll it on an external monitor?
- till what F-stop can you close down the 40mm lens till so start to see the spinning in the center of the frame?
-->>>

<<Jim,
excuse me but what do you mean here with proper exposed? Properly exposed for the limits of the device (keeping totaly open the frontal lens) or proparly exposed for what the image we want to photograph requests?>>

Well, I have to agree with Justin that "proper exposure is subjective". In general I mean that an under exposed image will begin to show grain much more noticeably than an over exposed one. Also, it appears that the "spinning glass" becomes more noticeable on a solid background (sky, grass, etc.) at longer focal lengths and above f/4


<<Also can I not understand why panning or tilting could have any effects on seeing the grain.>>

It's simple, in a static shot with a reasonably short depth of field, a slight bit of grain from the P&S can "dissapear" into the image. When you move the camera with a pan or tilt, the image changes but the grain pattern remains the same and because it doesn't move with the image it looks as though your looking through a dirty window as Justin commented.

<<Question, what model do you have? I have one of the later ones, which is revision 2002.>>

I believe I have the newest one in the US. THe one I orignally shot with had a different look, different motor switch and the iris wasn't as smooth. I know that the image coverage is enhanced (there was an issue with cine zooms needing to cover super 35 on older versions).

<<Meanwhile I called P+S Technik (I bought the equipment in Italy) and they said that this should not happen, that maybe for some reason my groundglass is spinning too slowly so I'll send them the equipment for a check.>>

Hey guys, one of the things I discussed recently with Mizell at ZGC was that the Germans designed the new motors with more bearing grease that some rental houses said had noticeably slowed down the motor. It was reccomended to them to open up the unit and put a drop of solvent on in order to dilute the grease and spin the glass faster. Obviously I would like to avoid this procedure. I'm a creative Jim...not a mechanic (in StarTrek Scottish).

<<This is basically what I experienced. If P+S thinks that this shouldn't be happening then I have this fault as well. I keep my lenses at T1.4 anyway. That's just what I like to do. Yes, I'm screwed up that way. I do a lot of things that DP's don't normally do... ;)>>

I do think this is probably the best rule of thumb Justin. Obviously there are some compromises that have to be made to get this quality of image with the XL and P&S vs 16mm or 35mm cost. I honestly tend to do the same in practice..that is keep everything open to 1.2/1.4 or a stop down. As you say, in this range with the motor on, you get a beautiful image and obviously a good deal of dimension with the limited dof. Where I see the real limitations so far (and I've got a long way to go with this setup) is with bigger shots, vistas etc, where there is a more uniform background.

One more thing, I just began expirementing with Heliopan circular polarizers for outdoor shots, and so far the results are nice. It gives a 2 stop or so effect while bringing more saturated color. I really need to test more and see how it compares to stopping at the relay iris in terms of grain.

One more, one more thing ;) Scott Billups considered the music video project that he shot with the P&S/XL1 setup to be the best miniDV footage he's ever seen, but also mentioned the need to use ND filters in order to get the dof of film. I'd like to talk to him and see if this was with the consideration of the grain issue. Without the time involved of a stop by stop lens by lens comparison, I would suggest that stopping down the prime lens with NDs may solve some of Istvan's issues with the need to shoot with more dof. I say this because my tests so far show that stopping the prime induces grain much more so than stopping down the relay iris with an open prime. I'll bet that ND's will give more flexibility still in terms of opening up dof without grain.

<<This is basically what I experienced. If P+S thinks that this shouldn't be happening then I have this fault as well. I keep <<Another reason to use a real monitor is that the exposure and color are difficult to judge with the viewfinder and an LCD monitor. The color in the viewfinder was very cold, almost blueish.>>

I hate to say it Victor but you've really got to spring for the B&W CRT viewfinder to round out this setup. You can see most grain in the VF while you're shooting and resolve the critical focusing inherent with the better lenses and dof. I use a 5" Nebtek on top just to give a color balance to the shot.

I actually did a quick calculation gauging how many hours are on my mini35.

~384 hours since the late July over the course of 48 shooting days.

43 of those days I was shooting straight without any off days.

I can't believe it. I'm getting tired just thinking about it.

Hi Jim,
thats a long answer...I realy like this forum!

<<< ... some compromises that have to be made to get this quality of image with the XL and P&S vs 16mm or 35mm cost. I honestly tend to do the same in practice..that is keep everything open to 1.2/1.4 or a stop down. ...>>>

I'm also agree that we have to accept and deal with compromises...and I LOVE the picures I saw till now!!! My only conceren is that I prefer for CUs longer lenses, and with F2.0 or F2.8 on a 85mm the actors can move on a 6' distance only 2 inches...which can become very frustrating.

<... I would suggest that stopping down the prime lens with NDs may solve some of Istvan's issues with the need to shoot with more dof. I say this because my tests so far show that stopping the prime induces grain much more so than stopping down the relay iris with an open prime. I'll bet that ND's will give more flexibility still in terms of opening up dof without grain...>

Maybe I'm missing something, but does the ND filter have effect on the DoF? I know the discussion on DoF is happening somewhere else, and maybe I will put there also the question as I start to become confused, so my question at this point is: if an ND6 forces me to open up the iris from F4.0 to F2.0, will I then have a DoF refered as T4.0 or T2.0??? I think that it is T2.0, so it would not help me.

I sounds very interesting what you wrote about putting some solution on the oil...I would also not do it myself, but it shows that there are improvments on the way.

Btw, I read somewhere that the new Pro35 has an excentrical spinning glass...
Thanks to everybody
Istvan

an ND filter will help you to further opening the lens and thus
shortening the DoF. So yes your DoF is smaller at T2 then it is
at T4. And you are correct to state T2.0...