Phocus 3.4.2 Windows - still no flash delay after 2+ years

[Alex]

I thought I'd bring this ongoing bug to attention (once again) (as it's been over a year since I last brought it up):

With the Windows build version of Phocus, the flash delay STILL does not work (whatever one dials in has no effect).
Please, for Multishot studio work it really does make a difference when the flash capacitors are on full stretch!

Alex

[Mellan Wilde]

it seems to work fine with me, if you have a problem, i guess it's better to contact customersupport@hasselblad.com, they may help.

[Alex]

it seems to work fine with me

That's great to hear; what version of Windows OS are you running it on?

Alex

Update - Or is it the mac version; it's worth knowing what &/or which so I can copy the basic setup for further bug testing elsewhere.

[Alex]

After doing some tests and discussing with Hassy HQ I discovered what and why delays would and would not occur in the way I expected them;

The duration of the variable Flash delay option in the preferences is varied itself by the duration of the subsequent exposure:
"Dialled in delay" - "duration of subsequent exposure" = "duration of delay to the start of the following exposure".

So a 5 second delay of an 1/60th sec. exposure will give you an actual delay of 4.98 seconds before the camera triggers the next exposure (big deal - no real discernible difference here).
However this also applies to a 5 second delay of a 2 second duration exposure which would result in a 3 second delay (such a scenario could occur if using a sequence of flashes to build up a high EV output value from a polarised flash unit (within a darkened studio setup)).
With a maximum of 10 seconds of programmable delay, the longest exposure one could use to obtain any practical use of such a delay would be 9 seconds, which would result in a 1 second delay to the start of the exposure.

With some of my work requiring very high EV values from relatively low power flashes, I'm often using sequences of 30x 800 joules which take more than 20 seconds to complete and hence why the delay system had no effect.

[Simon Bran]

Hi Alex,
I'm a bit confused, are you talking about the flash delay in the preference window, usually found in the top bar of the window which controls the time between exposures in a four shot sequence ? as far as i'm aware that function is there purely to allow studio flash packs to recharge at the end of each exposure during a 4 shot exposure, but if you are firing off the flash heads 30 times within 20 seconds, if you say set a exposure of 30 to 35 seconds, you should be able to fire off the 30 flashes with in that time( you say 20 seconds ish ) within each exposure of the 4 shot, so I don't see how would the delay between the exposures would help?
Simon.

[Alex]

Simon,

This query was born out of not understanding why I couldn't get any response from using the flash delay feature with whatever delay I set.
As it was something I ended up dismissing & bypassing by increasing the exposure time to beyond that of the flash sequence's requirement (as you pointed out), I pretty much forgot about it.

What brought me back to retesting it was when on a recent location shoot in a semi-blacked out artist's studio, I had instances of a bright sun making occasional appearances through gaps leaks in around the windows. With an added 7 second recovery time to the flash sequence duration, the ambient/daylight was varying the exposure values (and hence light variation warnings). This got me trying to close the lens shutter as early as possible (and use the flash delay to sort out the recovery), but with it not responding I ended up halting the shoot for an hour and redid the blacking out .

Alex

[Simon Bran]

Hi Alex, ok makes sense now, one thing you could try before  you wander off down the pub to wait for it to get dark,  is to use a small black card about the the size of a 5x4 dark slide (remember them?) and during the exposure slip it in front of the lens between flashes when the flash is recharging, works better for when you have a bit too much ambient light but it does mean you can extend the exposure with out adding more ambient light to the image, dosen't all ways work but it can get you out of a hole some times and possibly, for example, using a slightly wider aperture and fewer flashes or a longer exposure to allow more variable between the flashes.
simon

[Chris Gahran]

Alex,

I may be completely wrong about this because my gear is 2008 era multi-shot backs (CF-22MS) and I used them on Macs when I was working. Can you set your back to "Pinhole" in the camera setting? "Pinhole'" is chosen for shutter-less cameras used in a darkened studio.

Without me doing a test, the Manual (for Hasselblad CF Digital Camera Back Range) states that after selecting "Pinhole" as your camera, the Exposure Time ..."should be changed for cable-free exposure longer than 1/8 second, ensuring that it matches the shutter speed/exposure time on the camera/lens. The settings range from 1/8 second to 32 seconds (1/8 second is the default setting)."

I am thinking the shutter opens for 30 seconds, you manually do 20 pops and at 30 seconds the back will start the next exposure of the 4-shot sequence. (BTW, my backs do a dark calibration exposure then does the 4-shot sequence.)

Never tried this method because I used big high w/s strobes. If in the studio and I needed more light than the strobes could put out through Polarizing filters I might use tungsten hot lights and go to long exposure times (2-8 seconds).

Chris

[Alex]

Cheers Simon,

For the last shoot I did what you suggested and had a dark card that I could flip over the front of the lens (and then flipped back at the start of the subsequent exposure); it worked a treat with the power pack cooling fans quietly idling along.

Good idea Chris,

I got it setup, however when Phocus got wind that the back was connected to an H body it took over control of the body/lens and returned the exposure and shutter durations back into sync.

A

[Chris Gahran]

Alex,

Just did a test with my old gear. I successfully did tethered 32 second 1-shot and 4-shot captures with my CF-22MS set to "Pinhole". I believed the CF Series would be "in its own world" because they were the last Hasselblad backs made that could be attached to different cameras before the integrated H Series were produced.

I used a CF-22MS and a 555ELD camera with the lens set to "B" and the ELD body locked on Time. I could change the exposure time in Phocus.

(I stepped off the upgrade moving sidewalk years ago because I loved the 1, 4, 16 shot capability of the CF-22MS. Naturally, I am using an older version of Phocus and using Macs running an older OS but everything works well.)

So if Hasselblad makes a Digital Back that can be mounted on different camera bodies, the back may be "stand alone" like the old CF Series and will then allow using "Pinhole" as the selected camera.

Can you put your Back on a View Camera? If you can use the Back on a View Camera, can you put tape over the Back's electrical contacts to conceal that it is attached to a H Body? I have not used H Bodies but can you lock open the lens and aux curtain the way I can on an ELD? You then may be able to use "Pinhole" for making long exposures in a dark studio.

Chris