5D Sync Speed

Yes. The magnet goes in the "N" hole. The light comes on in the 4th position of the mode switch, just before the "test" position. No light when the switch is in the 3rd position. The light goes off just before the strobe fires as it should.

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Do you have all five pins in your bulkhead connectors? If so, I'll need to get connectors with all five pins to gain function of my strobes as you're experiencing. I only have four pins.

I think if the peak of the strobe light is delayed, as some of the older Ikelites seems to be (warm up time?), the effective xsync may be reduced. I've never had a problem using the 300D at 1/320 with the Inon strobes, but I've seen tests where a DS-125 will leave a small black line at that speed.

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The peak starts almost right at the beginning of the burn down curve (fading voltage). I think the start-up delay or warm up time is marginal compared to the entire flash duration @full power.

From my understanding older strobes are not able to emit fast and short preflashes due to their slow control circuits. I think that is the reason why Ikelite has upgraded some internal electronics (IGBT circuit) for preflash operation. But the tube hasn’t been modified in terms of warm up speed from what I’ve read.

5D and 10D are both rated with 1/200s x-sync. Interestingly the 5D seems to be a bit more critical. The curtain starts to show up slightly with 1/200s already. I can't see a difference between DS125 and Z220, just between the cameras and their shutter x-sync speeds. I don't have an old strobe here but DS125 is definitely fast enough from the results below.

Both strobes fired @full power and f32.

Julian

Interesting. We seem to get slightly different results for the 5D. Here's my test shot with the Z220 at 1/250 again

Seems like a fairly significant difference between two samples of the same camera model.

It's not surprising the full frame 5D has slower xsync. The shutter curtains have to travel 1.6 times the distance.

That’s really interesting Herb. While dpreview people check cameras for AF problems, we should check several camera copies in the store for x-sync quality and pickup the best one, hehe.

Honestly, I didn’t expect such variations between different 5D copies.

Yes, the full frame shutter has to travel a longer way. But we can crop the image afterwards anyway if we want to simulate a cropped sensor with faster x sync speed

Julian

I ran same test with curtain just slightly beginning to show at 1/200:

1/160

1/200

1/250

Herb,

Are you using all five pins in your strobe connections?

Herb,

Are you using all five pins in your strobe connections?

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No. I have the 4 pin Aquatica connector just like the one you're using.

I just took some more test shots. Used a couple of lenses 100mm and 15mm FE; tried a range of aperture, and strobe power setting. My 1/250 looks like your 1/200. I would not hesitate to use 1/250.