Re: Strobes, studio and students

[Igor PDML-StR]

lrc Tue, 24 Apr 2018 12:10:50 -0700 wrote:

The other is a bunch of $10 yongnuo triggers. I've had bad luck with 
their "high end" speedlights, but their cheap triggers are brilliant.


Is the triggers' briliance sufficient to illuminate the subject?
;-)

Cheers,

Igor


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Re: Strobes, studio and students

[lrc]

There are a couple of low-buck solutions.  One is a dumb speedlight with  an IR 
filter over it so it doesn't affect the image.

The other is a bunch of $10 yongnuo triggers. I've had bad luck with their 
"high end" speedlights, but their cheap triggers are brilliant.

On April 22, 2018 10:46:31 AM PDT, Bruce Walker  wrote:
>Mark, what you experienced is one of the reasons I don't recommend
>folks
>try that popup flash triggering hack. The other of course is the light
>pollution from the popup flash getting into the shot and flattening the
>contrast.
>
>But you have at least two possible issues with each student's camera:
>the
>x-TTL pre-flash, and the "red eye reduction" pre-flash. Either or both
>of
>these might be enabled in any given camera.
>
>The xTTL preflash is usually enabled even if manual exposure is in use
>because of the possibility for remote flash control. I used to use that
>feature with the K20D and the K-3 as a poor man's remote trigger. No
>danger
>of the popup flash appearing in the shot because it doesn't fire when
>the
>shutter is open.
>
>But it only works with flashes that support a pre-flash -- manufacturer
>dependent timing -- and some newer Chinese strobes that can be set to
>ignore 1-n pre-flashes.
>
>
>BTW, most PCB strobes come with a really long old-school PC-Sync cable.
>That might have helped with any of the students cameras that have a
>sync
>socket.
>
>-- 
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Re: Strobes, studio and students

[Igor PDML-StR]

I had the same thoughts as what Bruce has already written, so, no reason 
to repeat. The only difference is that I believe preflash cannot be 
disabled in digital-era *-TTL. At least not with PTTL, and I don't think

it was possible with the  Nikon D300, D700.

That preflash is the essence of how D*-TTL works: it is used for measuring 
the exposure.
So, I'd expect that the only way to disable the preflash on a *-TTL flash 
is to switch it to a non-*-TTL mode. That could be  the legacy-TTL mode
or a "manual" (i.e. using the specified level of power output, or 
just full-power-and-length) flash mode.
I don't know any if any camera has that implemented either of the two for 
the pop-up flash. I doubt, but who knows, maybe...



An additional thought of what to consider:
1. You can get a cheap simple non-TTL hot-shoe flash (with a 
low trigger voltage!)  as a trigger (for each of your students' cameras)

or
2. You can probably get a *-TTL-aware slave-trigger to the lights, 
connecting it via a PC-sync cable. (I have not checked if such triggers 
exist, but I would expect they should.)

This way you don't need anything added to the students' cameras.

HTH,

Igor



Mark Roberts Mon, 23 Apr 2018 06:47:18 -0700 wrote:

Bruce Walker wrote:


Mark, what you experienced is one of the reasons I don't recommend folks
try that popup flash triggering hack. The other of course is the light
pollution from the popup flash getting into the shot and flattening the
contrast.



Understood. But when you have to have groups of 3-5 students shooting
at once and only one radio trigger, well, optical triggering it is.


But you have at least two possible issues with each student's camera: the
x-TTL pre-flash, and the "red eye reduction" pre-flash. Either or both of
these might be enabled in any given camera.


I did check to make sure red-eye reduction was turned off. I didn't
see any options for turning off X-TTL pre-flash. I may have missed it
(we had a lot of different cameras, obviously) or it may not have been
an option in the very cheap DSLRs the students had.

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Re: Strobes, studio and students

[Rob Studdert]

I've used generic Yonguo RF-602 Radio triggers in group shoots, the
spill from the adjacent strobes would end up triggering the all the
others regardless of the lengths taken to shield the sensors. I keep a
couple of sets in my kit as the Elinchrom Skyports aren't always
reliable.

On 24 April 2018 at 09:50, J.C. O'Connell  wrote:
> although I havent used it, that looks like a good one as it has both a screw
> down foot and
> ttl feed thru as well as sync.
>
>
> On Mon, 23 Apr 2018 19:13:17 -0400, John  wrote:
>
>>
>>> On 4/23/2018 09:46, Mark Roberts wrote:
>>
>>
 Sync socket? Har! Not on any of the cameras here. I'm genuinely
 surprised they all had manual exposure as an option.

>>>
>>
>> Another thing ... somewhere around here I've got a little adapter that
>> fits on my hot shoe & has a PC Sync socket on it as well as a pass through
>> for the hot shoe.
>>
>> https://www.amazon.com/Vello-Universal-Hot-Shoe-Adapter/dp/B006TZ8QW4
>>
>>
>
>
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Re: Strobes, studio and students

[J.C. O'Connell]

although I havent used it, that looks like a good one as it has both a  
screw down foot and

ttl feed thru as well as sync.


On Mon, 23 Apr 2018 19:13:17 -0400, John  wrote:




On 4/23/2018 09:46, Mark Roberts wrote:



Sync socket? Har! Not on any of the cameras here. I'm genuinely
surprised they all had manual exposure as an option.





Another thing ... somewhere around here I've got a little adapter that  
fits on my hot shoe & has a PC Sync socket on it as well as a pass  
through for the hot shoe.


https://www.amazon.com/Vello-Universal-Hot-Shoe-Adapter/dp/B006TZ8QW4





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Re: Strobes, studio and students

[John]

On 4/23/2018 09:46, Mark Roberts wrote:



Sync socket? Har! Not on any of the cameras here. I'm genuinely
surprised they all had manual exposure as an option.






Another thing ... somewhere around here I've got a little adapter that fits on 
my hot shoe & has a PC Sync socket on it as well as a pass through for the hot shoe.


https://www.amazon.com/Vello-Universal-Hot-Shoe-Adapter/dp/B006TZ8QW4


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Re: Strobes, studio and students

[John]

I deal with that a lot at PPNC. They have shooting sessions at the convention 
and regional seminars. Last few years they've been switching over to systems 
with dedicated CaNikon modules and poor ol' Pentax shootin' me gets left behind.


But almost all the new studio strobes are still PocketWizard compatible, or else 
the vendor hangs a PocketWizard on them as a supplementary trigger. I went out 
and bought a second hand PocketWizard PlusII transceiver for $60 so I can play too.


That might be a semi-solution. If they're going to continue with photography, 
they're likely to need a radio trigger of their own anyway.


The first set of cheap Chinese triggers I bought would fire the first generation 
PocketWizard receivers. I think you can still find them on eBay under the 
"CowboyStudio" name. I just looked there, and a transmitter with two receivers 
was under $30.


On 4/23/2018 09:46, Mark Roberts wrote:

Bruce Walker wrote:


Mark, what you experienced is one of the reasons I don't recommend folks
try that popup flash triggering hack. The other of course is the light
pollution from the popup flash getting into the shot and flattening the
contrast.


Understood. But when you have to have groups of 3-5 students shooting
at once and only one radio trigger, well, optical triggering it is.


But you have at least two possible issues with each student's camera: the
x-TTL pre-flash, and the "red eye reduction" pre-flash. Either or both of
these might be enabled in any given camera.


I did check to make sure red-eye reduction was turned off. I didn't
see any options for turning off X-TTL pre-flash. I may have missed it
(we had a lot of different cameras, obviously) or it may not have been
an option in the very cheap DSLRs the students had.


BTW, most PCB strobes come with a really long old-school PC-Sync cable.
That might have helped with any of the students cameras that have a sync
socket.


Sync socket? Har! Not on any of the cameras here. I'm genuinely
surprised they all had manual exposure as an option.
  




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Re: Strobes, studio and students

[Gonz]

I was gonna say pre-flash, I've seen that before...


On Sat, Apr 21, 2018 at 8:28 PM, Mark Roberts
 wrote:
> So yesterday was "studio shoot" day for some of my photography
> students (and some from another class). Needless to say, it was a
> massive amount of work. But it was still fun and educational.
>
> Since we had to work with a lot of students we split things up and had
> them shooting in groups of 3 or 4 at a time. We standardized the
> lighting setup with a couple of Alien Bees with umbrellas (the school
> doesn't have any soft boxes). I had every student set his/her camera
> to manual exposure, ISO 100, 1/125 shutter speed and f/8. And since
> the school only has one radio trigger we had everyone use their
> camera's pop-up flash to optically trigger the main strobes.
>
> This setup worked well. Except when it didn't. Some cameras just
> didn't get along with this and produced dark photos. In fact, some
> (not all) produced uniformly dark shots even after changing aperture.
> I'd have two students with budget Nikons set to identical
> configurations and one would work perfectly and the other wouldn't.
> (Unfortunately, due to the number of students coming through, I didn't
> have time to make a list of cameras that exhibited the problem and
> those that didn't.)
>
> After she shoot was all done I think I worked out what was going on: I
> believe it was caused by the pre-flash that DSLRs use to meter before
> the main flash. I don't know the details but I suspect the pre-flash
> was triggering the studio strobes before the shutter had a chance to
> open. Of course, when you're on manual exposure there's no reason for
> the camera to have a pre-flash at all, but it may be left on because
> the manufacturer didn't want to add additional code to the firmware
> (in the case of the cheapest cameras). The cameras that seemed to
> yield a uniformly dark exposure regardless of aperture may have been
> operating in manual mode as far as ambient light was concerned but
> modulating flash power independently.
>
> Anyway, we solved the problem by letting any student whose camera had
> trouble shoot for a while with the radio trigger.
>
> Whew. A lot of work. But very gratifying in the end. Glad the
> semester's almost over.
>
> --
> Mark Roberts - Photography & Multimedia
> www.robertstech.com
>
>
>
>
>
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Re: Strobes, studio and students

[Mark Roberts]

Bruce Walker wrote:

>Mark, what you experienced is one of the reasons I don't recommend folks
>try that popup flash triggering hack. The other of course is the light
>pollution from the popup flash getting into the shot and flattening the
>contrast.

Understood. But when you have to have groups of 3-5 students shooting
at once and only one radio trigger, well, optical triggering it is.

>But you have at least two possible issues with each student's camera: the
>x-TTL pre-flash, and the "red eye reduction" pre-flash. Either or both of
>these might be enabled in any given camera.

I did check to make sure red-eye reduction was turned off. I didn't
see any options for turning off X-TTL pre-flash. I may have missed it
(we had a lot of different cameras, obviously) or it may not have been
an option in the very cheap DSLRs the students had.

>BTW, most PCB strobes come with a really long old-school PC-Sync cable.
>That might have helped with any of the students cameras that have a sync
>socket.

Sync socket? Har! Not on any of the cameras here. I'm genuinely
surprised they all had manual exposure as an option.
 
-- 
Mark Roberts - Photography & Multimedia
www.robertstech.com





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Re: Strobes, studio and students

[John Sessoms]

Using another flash to trigger studio strobes might work better with a 
plain old pre-TTL flash mounted on the hot-shoe. Just look for one 
without too high a trigger voltage.


I'm partial to Vivitar 285HV myself. The older "Made in Japan" models 
are better than the later "Made in China" versions, which don't seem to 
have the same durability.



On 4/22/2018 1:46 PM, Bruce Walker wrote:

Mark, what you experienced is one of the reasons I don't recommend folks
try that popup flash triggering hack. The other of course is the light
pollution from the popup flash getting into the shot and flattening the
contrast.

But you have at least two possible issues with each student's camera: the
x-TTL pre-flash, and the "red eye reduction" pre-flash. Either or both of
these might be enabled in any given camera.

The xTTL preflash is usually enabled even if manual exposure is in use
because of the possibility for remote flash control. I used to use that
feature with the K20D and the K-3 as a poor man's remote trigger. No danger
of the popup flash appearing in the shot because it doesn't fire when the
shutter is open.

But it only works with flashes that support a pre-flash -- manufacturer
dependent timing -- and some newer Chinese strobes that can be set to
ignore 1-n pre-flashes.


BTW, most PCB strobes come with a really long old-school PC-Sync cable.
That might have helped with any of the students cameras that have a sync
socket.



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Re: Strobes, studio and students

[Bruce Walker]

Mark, what you experienced is one of the reasons I don't recommend folks
try that popup flash triggering hack. The other of course is the light
pollution from the popup flash getting into the shot and flattening the
contrast.

But you have at least two possible issues with each student's camera: the
x-TTL pre-flash, and the "red eye reduction" pre-flash. Either or both of
these might be enabled in any given camera.

The xTTL preflash is usually enabled even if manual exposure is in use
because of the possibility for remote flash control. I used to use that
feature with the K20D and the K-3 as a poor man's remote trigger. No danger
of the popup flash appearing in the shot because it doesn't fire when the
shutter is open.

But it only works with flashes that support a pre-flash -- manufacturer
dependent timing -- and some newer Chinese strobes that can be set to
ignore 1-n pre-flashes.


BTW, most PCB strobes come with a really long old-school PC-Sync cable.
That might have helped with any of the students cameras that have a sync
socket.

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Re: Strobes, studio and students

[mike wilson]

> On 22 April 2018 at 02:28 Mark Roberts  wrote:
> 
> 
> So yesterday was "studio shoot" day for some of my photography
> students (and some from another class). Needless to say, it was a
> massive amount of work. But it was still fun and educational. 
> 
> Since we had to work with a lot of students we split things up and had
> them shooting in groups of 3 or 4 at a time. We standardized the
> lighting setup with a couple of Alien Bees with umbrellas (the school
> doesn't have any soft boxes). I had every student set his/her camera
> to manual exposure, ISO 100, 1/125 shutter speed and f/8. And since
> the school only has one radio trigger we had everyone use their
> camera's pop-up flash to optically trigger the main strobes.
> 
> This setup worked well. Except when it didn't. Some cameras just
> didn't get along with this and produced dark photos. In fact, some
> (not all) produced uniformly dark shots even after changing aperture.
> I'd have two students with budget Nikons set to identical
> configurations and one would work perfectly and the other wouldn't.
> (Unfortunately, due to the number of students coming through, I didn't
> have time to make a list of cameras that exhibited the problem and
> those that didn't.)
> 
> After she shoot was all done I think I worked out what was going on: I
> believe it was caused by the pre-flash that DSLRs use to meter before
> the main flash. I don't know the details but I suspect the pre-flash
> was triggering the studio strobes before the shutter had a chance to
> open. Of course, when you're on manual exposure there's no reason for
> the camera to have a pre-flash at all, but it may be left on because
> the manufacturer didn't want to add additional code to the firmware
> (in the case of the cheapest cameras). The cameras that seemed to
> yield a uniformly dark exposure regardless of aperture may have been
> operating in manual mode as far as ambient light was concerned but
> modulating flash power independently.
> 
> Anyway, we solved the problem by letting any student whose camera had
> trouble shoot for a while with the radio trigger. 
> 
> Whew. A lot of work. But very gratifying in the end. Glad the
> semester's almost over.

Interesting phenomenon.  If that had been me, with my present cohort, half of 
the studio gear would have been broken.  They are getting worse as the year 
progresses.  I can't wait for it to be over.

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Strobes, studio and students

[Mark Roberts]

So yesterday was "studio shoot" day for some of my photography
students (and some from another class). Needless to say, it was a
massive amount of work. But it was still fun and educational. 

Since we had to work with a lot of students we split things up and had
them shooting in groups of 3 or 4 at a time. We standardized the
lighting setup with a couple of Alien Bees with umbrellas (the school
doesn't have any soft boxes). I had every student set his/her camera
to manual exposure, ISO 100, 1/125 shutter speed and f/8. And since
the school only has one radio trigger we had everyone use their
camera's pop-up flash to optically trigger the main strobes.

This setup worked well. Except when it didn't. Some cameras just
didn't get along with this and produced dark photos. In fact, some
(not all) produced uniformly dark shots even after changing aperture.
I'd have two students with budget Nikons set to identical
configurations and one would work perfectly and the other wouldn't.
(Unfortunately, due to the number of students coming through, I didn't
have time to make a list of cameras that exhibited the problem and
those that didn't.)

After she shoot was all done I think I worked out what was going on: I
believe it was caused by the pre-flash that DSLRs use to meter before
the main flash. I don't know the details but I suspect the pre-flash
was triggering the studio strobes before the shutter had a chance to
open. Of course, when you're on manual exposure there's no reason for
the camera to have a pre-flash at all, but it may be left on because
the manufacturer didn't want to add additional code to the firmware
(in the case of the cheapest cameras). The cameras that seemed to
yield a uniformly dark exposure regardless of aperture may have been
operating in manual mode as far as ambient light was concerned but
modulating flash power independently.

Anyway, we solved the problem by letting any student whose camera had
trouble shoot for a while with the radio trigger. 

Whew. A lot of work. But very gratifying in the end. Glad the
semester's almost over.
 
-- 
Mark Roberts - Photography & Multimedia
www.robertstech.com





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