Back from the 1st day of the 1st gig with the XL-H1
 

I have a question about shutter speeds, but let me explain what's going on first....

So today is the 1st day the XL-H1 is deployed on a production job.
I'm currently producing a 2-day Aerobic Workout DVD called "The Voluptuous Ladies Of America Vol.1"

Don't ask!

I normally only take-on narrative movie or music video projects, but I was anxious to do some stuff with the camera so I agreed. All the other productions with the XL-H1 don't start for another 2 weeks and beyond. Plus, this production seemed fun and the Executive Producers are wonderful people.

Anyhow....the day went well, and the XL-H1 is the master of a 3-camera Shoot. B & C cameras are a pair of Sony HVR-Z1U's. This is a total Green Screen Studio shoot recording 6 pretty ladies with nice big....ummmm...well, (cough) ummm......*where was I?* OH YEA....so all 3 cameras are @ 60i and various shutter speeds and what not. I would like to have shot 30p, but I would have needed 2 more XL-H1's and that wasn't happening as the budget I was given was only $5800 so I couldn't buy them and I couldn't find any rental houses that had them yet. I wasn't going to hastily buy another XL-H1 because I kinda think I want an HVX-200, as I wait on the shootout.

Anyhow, the lighting is perfect. I hired a good DP friend of mine JARRED HOY to take charge of the camera department. Jarred is setting the shutter speeds on the Z1U's (from as low as 1/8th up to 1/250th) for various looks and effects and stuff. The XL-H1 is set at 1/60th always, but one time he dropped the XL-H1 from 1/60th to 1/30th.

During a wardrobe change we played back some footage from all cameras to see how things were going and looking.
sidenote: The HVR-Z1U's are DAMN NICE cameras! The images are gorgeous.
Now...the XL-H1 was outstanding and produced the prettiest picture of all the cameras. It was mindblowing to look at. When we reached the XL-H1 footage that was shot at 1/30th shutter speed in 60i mode, the footage dropped the reality look instantly and became...kinda.....movie like. It was dreamy and surreal looking. One of the P.A.'s said "WOW....it looks like their dancing under water". She was right. I said it myself as well. But get this, the 60i-1/30th shutter speed footage was NOT blurrry, it was NOT slow motiony, it was NOT reality looking, it was NOT like anything I had seen before as I was looking at these ladies dance in front of a 20' tall chromakey backdrop.

So tell me....what is 1/30th shutter @ 60i doing? Is that the same as 30p kinda sorta? CF30 was my favorite setting on my Z1U, but it didn't look ANYTHING like this. I don't recall what the Z1U looks like on 1/30th shutter speed with no CF modes, but I don't think it was like this. Is 1/30th doing something special to 60i footage? 30 goes into 60 two times, so it must be something special about those two numbers. LOL

I did see the DP & AC go in and tweak the image presets (black strecth, cine gamma, etc...), man I don't know. Maybe I'm just trippin' off the amazing clarity & color created by the XL-H1. But there's gotta be something special about 1/30th & 60i, and more importanlty, how come that is not standard shutter speed setting for 60i? Why 1/60th?

- ShannonRawls.com

Well it should be like 30p 1/30th.When I think about it it should look like 1080p 'cos but the time the ccd send the 2nd field the image is still the same...wow, I never realise that before, that's cool!

Just tought of another thing!
If you can overcrack the camera to 120i with 1/60th shutter you can get 60p, 1/60th out of which you can get 30p,1/60th and that's real full res 1440x1080.
Now...how to overcrack the camera?

I wonder if maybe the DP did that to let more light in (1/30 is technically a slow shutter speed for the camera I think) that's my guess.

With most interlaced cameras, when you shoot at 1/30 sec you get field doubling (same data written to both interlaced fields). This results (theoretically) in a 50% loss of vertical resolution.

I have no idea how this works on the Canon, but reviews of the Z1 have stated that this happens. However, if you're capturing with i.Link downconvert enabled, or if you shoot in DV/DVCAM mode, this isn't an issue since 1080/2 = 540 which is still greater than the 480 lines needed for standard definition. So you should get something which looks like 30p in DV mode.

Were you looking at the footage on an HD or SD monitor? Actually, the Z1 has a menu option to output 480/30p via the component interface in HDV mode. Unfortunately it won't do that via firewire.

Does anyone know if the camera allows for 1/25th shutter speed for us PAL dudes? Does the shutter change speeds up and down in values of 1 or is it pre defined levels?

Of course it does...I mean I don't know but I pal versions of the other 2 xls so I'm guessing it's the samo thing.
...neah, there's no way they're not going to include 1/25th.

Yes Ashley, we have got 1/25 th here in our PAL world. As well as 1/16000, 8000, 4000, 2000, 1000, 500, 250, 120 (!), 50, 12, 6, 3 and CS "Clear Scan" . In CS you can select from 1/50.2 and up to 1/200.3. Not all numbers seem to be accessible but pretty many. This is to be able to syncronize to CRT screens to not get the black band across the screen.
The book points out specifically that 1/3 is only available with the HD 20x L IS lens.

Clear Scan
 

Is for your everyday need to shoot on computerscreens or TV;s and want to get rid of the upcoming black line!

That seems to be the case here. At 1/30th the two fields are identical and there is a loss of vertical resolution. On a Putora chart at 1/30th Target 6 (84 L/mm on a 1/3" target) is clear but Target 7 (111 L/mm) shows aliasing in the vertical direction. At 1/60th Target 7 is clear as is Target 8 (147.2 lines). So at 1/30th the resolution is between 84 and 111 lpmm and at 1/60th it is between 147.2 and 194 lpmm (Target 9 which is not visible). You could argue that the former case has half the resolution of the latter but you can't prove it at least not from these observations. Nonetheless it is clear that there is appreciable loss of vertical resolution.

Great I thought it would have it.. I guess the res loss really depends on what your target media is, if your shooting HD for an SD target then maybe 50i and 1/25th is the go rather then 25f? Just a thought - I'll look into it more and do some tests once I get my XL H1 *smile*