Time and Aperture with Manual Flash Set Up

I want to use a small old Canon flash, called ED, to experiment with time and aperture. I am too lazy to use a film Camera and it is NOT save to attach ED to my digital camera.
I came up with this set-up. Camera on Tripod in manual mode. Attached by remote cord is a SB-900 set to manual, 1/128 power and 200mm zoom. Having the SB-900 dialed down as much as possible and pointing away from the scene should ensure that it has no effect on the picture taken.
Another word of advice: Did you ever wonder why Pro photographers seem to be fascinated with the color black in their fashion choice? Remeber the GPP shootout? All three photographers  and all assistants wore black T-shirts.
Well, on this occasion I also wore a black t-shirt because I do not want to act as an unwanted reflector. Which might have had an influence in this set-up when the trigger flash points towards me.

ED is attached to the Chinese DP1 photocell. The SB-900 in manual mode does not emit any pre-flash, so I could have taken any photocell. I used the DP-1 to run a mini test. (No pictures)
When I set the SB-900 to manual and the DP1 to expect a pre-flash, it does not fire when I take one picture. When I take two in quick succession it does fire. When I set the DP1 to normal operation it fires reliably. No pre-flash in manual mode! This is the kind of useful information which is either not in the manual or buried somewhere so it always handy to run the tests.

Another little side remark: I took the picture of the set-up with a fairly recent point and shoot the Canon Power Shoot A2100. You can see in the first picture above that I forgot to switch off ED so it fired and nuked the SB-900 and the plant. When taking the picture from the front I thought to keep it on and make a number of pictures in succession. I thought that the recycle times of my 2009 Digi-Knips would surely be faster than ED from the year 1975. (He is older than most participants in Davids GPP workshop.) So I hoped to get one picture with ED firing and the next one without. Man was I wrong! ED kept up the recycle times right with the Powershot all pictures had ED firing. I had to switch it off to make the shot above. Way to go ED!!! (If you look at my reflection in the glass door you see that I really wore a black t-shirt.)

I used a stuffed Toy of my dog Wolfi as a model and placed it exactly 4 m away from the flash into the lawn.

Now the set-up is complete and I am ready to go.






At least that's what I thought!
Wolfi thought: "Oi! That is MY toy!"
I could convince him to lend me the toy for a good cause in the end and I will post the example pictures tomorrow.