Strange RZ Pro II hotshoe issue

[z0624]

Tried to research this but couldn't come up with anything definitive.  I have an RZ Pro II with an adapter and a Leaf Aptus 22.  I have the sync cable to the back and everything works normally.  When shooting in the studio, I put a pocketwizard in the hotshoe.  I've noticed the exposures are roughly 1.5 stops underexposed.  This is consistent at any of the shutter speeds. 

If I run a sync cable from the pc socket of the aptus to the pack, the exposures are dead on.  So I was thinking it was a delay with the pocketwizards, but I then put a pc to miniplug and used the pocketwizard as a wireless relay to the packs and the exposure was dead on.  So it sounds like there's something funky with the hotshoe. 

Someone mentioned changing the "contact time" of the Multimax which defaults at .8 so I've gone up and down from that setting and after a few tenths in either direction, the underexposure starts to increase.

So to sum it up, I've read about people that have no problem using the hotshoe and others where they get no triggering from the hotshoe.  I think I'm the only that gets an underexposure issue.  I also tried with all three RZ lenses I have and it's pretty much the exact same issue.

I figured I'd post it here since there are plenty of knowledgeable people here.

[HarperPhotos]

Hello,

Interesting. I have a Mamiya RZ ProIID and non D and a Leaf Aptus75 which I sync with the cable between the lens and the back.

I use the basic Pocket Wizard and the new Pocket Wizard MiniTT1-Nikon transmitter on the hot shoe without any issues.

Sorry but I don’t have a clue to what is happening with you system.

Cheers

Simon

[z0624]

Hi Simon,
I know.  It's the strangest thing.  I can take the back off and put it on the H series Hasselblads with pocketwizards and take shots with exposure dead-on.   I used 2 different flash meters to confirm the flash output. Leaf histogram is with .1 of the exposure that the flash meter reads.  I can go from 1/400 down to where the ambient light starts influencing the shot and the exposures are still consistent.  

But when I use the pocketwizard in the hotshot, histogram is pretty consistently 1.5 to 1.8 underexposed.  

I found the workaround going off the PC socket of the back but the hotshoe is so much cleaner and one less cord.

The only thing I can think of his some timing delay and I'm getting enough of the flash to make the exposure albeit 1.5 stops under.  I guess I can see if it's -1.5 when I'm increasing the power.   The tests shots were made at f2.8 at ISO 50.  

[marcel b]

I have the same issue with my rz and use an adapter instead of the hotshoe. don't know why, but it doesn't sync fast enough with the hotshoe. never had anything like this, when shooting film.

[yaya]

Just suggesting the obvious but have you tried:

Cleaning/ tightening the hotshoe

Swapping the PW units

Another body

[z0624]

I have the same issue with my rz and use an adapter instead of the hotshoe. don't know why, but it doesn't sync fast enough with the hotshoe. never had anything like this, when shooting film.

Really?  That's crazy.  I don't feel quite as badly now that I know I'm not the ONLY one. 

So do you sync your strobes off of the pc port on the digital back since the lens port is used for the sync cable to back?

[z0624]

Just suggesting the obvious but have you tried:

Cleaning/ tightening the hotshoe

Swapping the PW units

Another body

Hi Yair,
I tried cleaning the hotshoe but I don't think I can tighten it on the RZII.

I tried another Multimax and a PlusII.  I also tried 2 different Profoto PW packs and substituted another Multimax for the internal PW receivers.

I may try another body if I come across a cheap one.  My RZII is near mint but these can be found pretty inexpensively.

The other 2 links I found which may sort of be similar to what I'm experiencing aside from Marcel are:

http://www.talkphotography.co.uk/forums/archive/index.php/t-316181.html
http://www.apug.org/forums/forum51/86572-rz67-proii-flash-syncing-lens-x-sync-connection.html

I just thinks its bizarre in that I can actually compensate for it by bumping up the power on the strobes or by scrapping the use of the hotshoe.  I'm just one of those people that like to know why it's happening, though.

[marcel b]

I sync the radio trigger to the back, and, to be honest, I never asked why, I just accepted it and used a hotshoeadapter with sync cabel to the back ever since ;-)

[MarkoRepse]

I have the same setup and get this too (but with skyports). Its "normal". Have you tried shooting in ambient/constant light only? Because with this setup you will get underexposure at ambient light at speeds of 1/400 and 1/250, it really depends on the lens. 1/125 and slower seems to be fine with my setup. I'm guessing the same problem occurs when you shoot with flash, basically the flash shoots too early relative to the back which then clips the light. Syncing with the back obviously fixes this. This whole underexposure thing is in fact known by Leaf. I contacted their tech support and they confirmed its normal. Read:


It seems that your equipment is OK.

What you are seeing is a "Large Format" limitation in Digital Photography. When you use a shutter speed of 1/250, the actual shutter speed is about 1/350 and when you use 1/400 it’s about 1/550.

The reason behind this is that the back start to expose about 100 millisecond after the sync signal.

Unfortunately there is nothing we can do about it. The workaround is to compensate with aperture.

Regards,
Meir


What is even stranger is that some people (Simon, and others) don't have this issue. Changing the body won't help. The RZ IID with the electronic plate and no cables should work properly, but the Aptus22 backs have other issues with that... Its really unfortunate, the RZ is great but this whole tech mess is a headache. However if you only shoot with flash indoors it shouldn't be a problem.
Marko

[z0624]

I sync the radio trigger to the back, and, to be honest, I never asked why, I just accepted it and used a hotshoeadapter with sync cabel to the back ever since ;-)

Hi Marcel,
So you use something like this with the sync cord going to the back?

http://www.bhphotovideo.com/c/product/89982-REG/Hama_HA_6952_Hot_Shoe_Adapter_2.html

I'm thinking I'll get something similar but clamp the pocketwizard out of the way...maybe to the tripod leg.

Regards,
Ricardo

[marcel b]

yes ricardo, that's it, I use the hensel triggers and never had any issues again.

but I also never noticed things like double flash sync on slow speeds, like mentioned in the links above - this looks more to me like a malfunction of the sync socket on the lense

[z0624]

Just to update those that contributed to the thread.

I now have the pocketwizard along with the small sync cord that comes with it, connected to the PC socket of the back as the x-sync of the lens has the Leaf sync cable connected to it. 

Wireless flash sync is right on the money at all sync speeds with the exception of 1/400 and as referenced by Markos post.  I might be getting a little underexposure one click slower but by 1/250, the histogram is pretty much spot on with my 758DR.

My hotshoe definitely is triggering twice, once at the instant the shutter is triggered and apparently once as it finishes it's exposure.  I wasn't able to tell if it's something tied to the rear curtain or mirror flopping but there's definitely 2 trigger points setting whatever (flash or PW) is connected to the hotshoe.  This occurs regardless of which of the 3 lenses I have.  Assuming this must be the body and that of a few others I've read about such as Marcel's but there are those that don't exhibit this problem.

Thanks to all on LL.

[Sheldon N]

Late to the party, but I'll echo that my RZ67 Pro II and Aptus 22 work the same way. I have to use a sync cable from the back to the wireless flash trigger in order to get proper flash exposures.

[AlDoori]

i do not experience that problem.
i have a leaf aptus 22 connected via synch cord to RZ pro, proII or pro IID and sync to a broncolor flash system with  different broncolor IR triggers mounted on the hot shoe.
a quick test shows that exposure is constant at speeds from 1/3o to 1/4oo sec.

[z0624]

i do not experience that problem.
i have a leaf aptus 22 connected via synch cord to RZ pro, proII or pro IID and sync to a broncolor flash system with  different broncolor IR triggers mounted on the hot shoe.
a quick test shows that exposure is constant at speeds from 1/3o to 1/4oo sec.

I didn't try IR triggering...just my PW Plus II and Multimax.  If you have any PW or RF triggers in general, I'd be curious to know if it happens.  Otherwise, there are those that don't experience what me, Marcel, Marko and Sheldon experience.