Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
01-04-2016, 11:33 PM - 9 Likes   #1
Pentaxian
mcgregni's Avatar

Join Date: Sep 2012
Location: Surrey, England
Posts: 2,602
Pentax & Cactus Multi-Flash Wireless HSS Demo

After all the recent talk here about Optical Slave & Delay settings I was really pleased recently to put it all together and get things working in practice. One of the main uses for the Cactus RF60 I had in mind was for use in HSS situations, in combination with my two Pentax AF-540FGZ (I & II) flashes.

Of course we all know that one of the big issues for Pentax users of HSS wireless flash is that it ties up one P-TTL HS capable flash on the camera to serve as the essential trigger. So I only had one other flash as a slave, and sometimes I'm looking for more power, or just for some more sophisticated lighting arrangement during HSS. I really didn't need more than two system dedicated flashes, and so in the interests of economy I bought the RF60 .... and combined it with a V6 transceiver for the added convenience of its remote power and zoom control.

So this is a 'mixed mode' flash configuration .... the Pentax Dedicated flashes must operate in P-TTL mode when in High Speed Sync, and of course the Cactus is a manual mode flash. Here is how the 3 flashes were used ....


1) The Cactus RF60 was placed on a lightstand and used as a 'Main' light facing the subject from the front. This flash had a Gary Fong Powersnoot attached to channel and focus the light narrowly and 'replace' lost power through the very short exposure times I'd be using ......


Name:  HSS-Teddy-2.jpg
Views: 2115
Size:  65.6 KB



2) The Pentax AF-540FGZ was placed in a softbox off to the subjects left to act as a fill-in and to control the shadows created by the frontal main light .....

Name:  HSS-Teddy-4.jpg
Views: 1393
Size:  223.6 KB


And now you can see my willing subject The only one around that morning who had nothing better to do


3) The camera (Pentax K7 with SMC F35-70mm) had the AF-540FGZII mounted on top of the V6 .... the Pentax Flash was set to Wireless HS 'Control' mode, acting as a controlling trigger only (no contributing lighting), and a Gary Fong Lightsphere was attached with the flash head pointing straight up .... (a little like this shot .... ) The only difference from this image is that I also had the V6 on the camera (under the flash) as I was using it to control the RF60s power and zoom.


Name:  GF Lightsphere K7 1.jpg
Views: 1372
Size:  156.2 KB



As the shooting position was in between the two flashes I needed to get the triggering light into the optical sensors of both slave flashes, which were 180deg opposite each other. The Lightsphere sent the signal in all directions and so I was able to trigger both flashes with no issues.


Here is the position of the Main light in relation to the subject ....


Name:  HSS-Teddy-3.jpg
Views: 1357
Size:  194.2 KB


And these two show the relative positions of the two flashes ... the shooting position was in the middle of them ....


Name:  HSS-Teddy-1.jpg
Views: 1277
Size:  155.5 KB


Name:  HSS-Teddy-5.jpg
Views: 1295
Size:  164.1 KB



The purpose of the HSS technique was to balance and control the high contrast in the scene. There was bright sunshine from the left (behind the subject) which added a nice free rim-light , but the Teddy's front and face were in shadow (he'd have been squinting terribly if I'd faced him into the sun) .... if I'd exposed for the shadow on his front then my background would have been overexposed, the sky massively. I needed to keep a fairly wide aperture because of the busy distracting background ... and, well, this is a portrait after all (and we're supposed to set wide apertures for portraits, right ?! )

So I settled on around F4.5-5.6, and an ISO of 200 for good quality. When I pointed the camera at the background and metered to get a good exposure there, the time value was around 1/500th sec. I also wanted to tone down the background as well to emphasise the subject, so I dialed the time value even shorter to between 1/800th - 1/1600th sec (the light kept changing a bit) ..... I kept it at around 1.3 - 2.0 stops below the meter-centre.


This was the result of this 'ambient' exposure without the flashes firing .....

Name:  HSS-Teddy-8.jpg
Views: 1267
Size:  62.7 KB


So clearly it was time to fire up the flashes .... The Cactus RF60 was set to HSS Sympathy mode, and Optical Slave mode 2 (OS2) to fire on the Main Flash. However as we've been discussing on the recent thread about this, when a P-TTL control flash is used there is an additional wireless instruction pre-flash, which the RF60 is triggered by, and so I needed to set a delay of 15ms also.

The Pentax Flash operated in wireless P-TTL mode, as a single slave as far as the P-TTL system was concerned. The P-TTL metering system would not take account of the RF60 manual flash at all, because the RF60 does not fire until the actual exposure, and so the camera does not see its effect during the pre-flash. In effect there are two side-by-side but completely independent flash exposures. I needed to test and fine tune each one in isolation before combining them. The RF60 power was controlled from the V6 on camera, and the Pentax flash was controlled by Flash Compensation on the camera also, so I never had to move to the flashes to adjust their outputs.


Here is one shot using just the main RF60 light, showing its shadow effect ....


Name:  HSS-Teddy-16.jpg
Views: 1367
Size:  144.4 KB



And here's a couple showing the full result with the fill-in flash from the softbox with the underexposed background as well ....


Name:  HSS-Teddy-11.jpg
Views: 1276
Size:  75.5 KB


Name:  HSS-Teddy-15.jpg
Views: 1243
Size:  62.0 KB

I was a happy HSS Flashing Bunny after that testing session. To get everything synced and be using two off-camera flashes (one manual and one P-TTL) was exactly what I'd been wanting to achieve, and I am sure will lead to better quality lighting effects for HSS work. Both the Pentax P-TTL wireless system and the Cactus Manual one proved their worth and made a great HSS partnership !

Now, next I just have to persuade a far better looking model to stand around in the sun for me ....

01-05-2016, 01:13 AM   #2
Pentaxian
mike.hiran's Avatar

Join Date: May 2007
Location: portland
Photos: Albums
Posts: 1,477
is the rf60 required or can 2 v6's be used (one on the main light, one on the body)? And is there any special settings on the v6 mounted on the body (besides being in transmit mode, having the right channel set, etc)?

Thanks so much for doing this - I've been meaning to get this hss stuff figured out, but haven't had the time lately.
01-05-2016, 02:07 AM   #3
Pentaxian
mcgregni's Avatar

Join Date: Sep 2012
Location: Surrey, England
Posts: 2,602
Original Poster
This is the 'optical trigger' approach, using the RF60's light sensor (the red panel on the front) ... The Pentax flash is triggered in the same manner, and that's why both flashes are angled with the bodies facing inwards to the shooting position, as they have to 'see' the light coming from the on-camera Pentax control flash.

The V6 can't provide a radio trigger signal for the RF60 because the camera doesn't generate a signal it can recognize. The V6 doesn't even 'know' that photos are being taken. However it's radio control signals can still be used to control the RF60 power and zoom settings. I used this as a convenience really .... There's no actual need to use a V6 for this HSS technique with an RF60 at all.

The V6 is set to 'TTL Pass-through' mode, allowing the special HSS specific information to be passed through the contacts to the Pentax flash on top. As far as the camera and flash are concerned, they are directly connected.

The specifics of the RF60 delays and optical slave modes are being well covered in the thread concerned with this, just a few items down on the threads list here in the flash forum.

Assuming you want the convenience of power and zoom control like I did, then if you have an RF60 you only need 1 V6 to control that. There is no point in extra V6 receivers (in receiver mode attached to a slave flash) for HSS because there is no radio triggering available ... The slave flashes are either dedicated system HSS flashes and controlled automatically from the controller trigger flash, or they are 'dumb optical slaves' like the RF60, and may or may not need specific delays programmed depending on how they react to the pattern of pre-flashes from the controller flash.


The radio controlled triggering method with both a transmitter and receiving V6's is a different technique altogether and I haven't tried it or even thought about it. ClassA devised it I believe and has been advising recently on its use to another member who was having some problems with it .... Check though the recent threads here for that information.


HSS flash is great fun I find, and even more so with two lights. Good luck with your experimenting!

Last edited by mcgregni; 01-05-2016 at 02:19 AM.
01-05-2016, 03:33 AM   #4
Senior Member




Join Date: Jan 2013
Photos: Gallery | Albums
Posts: 164
Thanks for the experience report! I'm still running with a number of V5's and its interesting to get hands on reports on what can you do with the newer version. I'm probably not going to use the Cactus flash, as I've got enough many of the speedlights already, but the possibilities of a gradual upgrade path is certainly interesting.

01-05-2016, 12:41 PM   #5
Pentaxian
mcgregni's Avatar

Join Date: Sep 2012
Location: Surrey, England
Posts: 2,602
Original Poster
Glad you found it interesting . There's been a lot of talk recently about HSS work with the Cactus manual flash that I thought it would be good to see something in practice, even fairly simple like this .... It would have been better though I I'd got some hot glamour model in a bikini , I realise that! The bear came cheaply though ....

I am just really pleased that the Cactus option has proven robust and combines well with the Pentax automatic system. It's certainly cheaper than getting another dedicated system flash, and it's added more versatility to my off-camera possibilities generally, so thoroughly good value. The system can expanded in two ways ... Another Cactus flash which would give independent manual control from the V6 (one flash on group A, one on B), or I could get another V6 and use it with one Pentax flash for when I didn't need P-TTL. .
01-06-2016, 05:21 AM   #6
Pentaxian




Join Date: Nov 2008
Location: Melbourne, Australia
Photos: Gallery | Albums
Posts: 578
Thanks McGreg. Nice seeing real life examples. Yeah, a shoot with a real person would be nice.

Also a comparative shoot staying at 1/180 and using an ND filter (so not relying on HSS) would be great for newbies who are worried about of lack of HSS capability.

Howie Be
01-06-2016, 07:40 AM   #7
Pentaxian
mcgregni's Avatar

Join Date: Sep 2012
Location: Surrey, England
Posts: 2,602
Original Poster
Technically its the alternative approach, sure. I suppose in theory, assuming the exposure balance ends up being the same, the end results should look the same between an HSS or ND filter approach .... ?

I know the filter technique has supposed power advantage, in that it's using the 'power sweet spot' at the maximum sync speed, so allowing the best relationship between lowest available light and flash power. Whereas HSS has the power disadvantage that it's fighting against the shorter exposure times, and exponentially as those get shorter. (I was able to fight back against this effect though and replace lost power with my powersnoot and 2nd flash, so I never felt any power loss .... In fact, so effective was the Powersnoot that I never used the RF60 at a higher power than 1/8th, and most shots were at 1/16th power ... Hardly a struggle).

My main reservation with a filtered approach would be about exposure balancing flexibility. For the range of shots in varying lighting I shot, I was working within a 3 stop below centre range (1/500th to 1/2000th secs). A 2 or 3 stop ND might work but I'd be worried about hitting the brightness buffers all the time if stuck at 1/180th. And I was shooting at F5.6! Most high quality portraits of this type would ideally be shot at between 85-200mm, and at an aperture of F4.0. So that would be even more of a limitation.

I am sure an ND filter could provide the contrast control needed in not too bright conditions that were fairly static, but I feel the extra control and flexibity over ambient exposure that the HSS technique allows (you can get down to 1/8000) with some Pentax cameras) is very valuable.

But I promise, if I can get a super fit model to pose for my next shoot, I will definitely try and persuade her to hang longer while I try out some filters as well !
01-06-2016, 02:55 PM - 1 Like   #8
Pentaxian




Join Date: Dec 2010
Location: Ontario
Photos: Gallery
Posts: 3,332
Thanks for the demo.

You probably already know, but the guide numbers for HSS at the various shutter speeds are in the back of the manual if you wanted to compare HSS vs ND filters.

QuoteOriginally posted by mcgregni Quote
.... It would have been better though I I'd got some hot glamour model in a bikini , I realise that! The bear came cheaply though ....
No reason the teddy couldn't wear a bikini. Or make it a lingerie shoot and put the teddy in a teddy.

01-07-2016, 04:59 AM   #9
Pentaxian
Class A's Avatar

Join Date: Aug 2008
Location: Wellington, New Zealand
Posts: 10,620
QuoteOriginally posted by mcgregni Quote
After all the recent talk here about Optical Slave & Delay settings I was really pleased recently to put it all together and get things working in practice.
Wow, very comprehensive description!

QuoteOriginally posted by mcgregni Quote
Of course we all know that one of the big issues for Pentax users of HSS wireless flash is that it ties up one P-TTL HS capable flash on the camera to serve as the essential trigger.
The only ways to avoid tying up one P-TTL HSS capaple flash as the essential triggers I know are
  1. using Acon triggers for Pentax. I cannot comment on them personally, but others appeared to have used them successfully.
  2. my "HSS with manual gear only"-trick.

QuoteOriginally posted by mcgregni Quote
Both the Pentax P-TTL wireless system and the Cactus Manual one proved their worth and made a great HSS partnership !
Glad it is working out for you so nicely!

QuoteOriginally posted by mcgregni Quote
It would have been better though I I'd got some hot glamour model in a bikini , I realise that!
We will be patient till you have organise the hot glamour model. If you can't organise a bikini as well, don't worry, we won't complain. Just don't forget the NSFW tag.

Last edited by Class A; 01-07-2016 at 05:20 AM.
01-07-2016, 05:12 AM   #10
Pentaxian
Class A's Avatar

Join Date: Aug 2008
Location: Wellington, New Zealand
Posts: 10,620
QuoteOriginally posted by vagrant10 Quote
is the rf60 required or can 2 v6's be used (one on the main light, one on the body)?
You don't need an RF60 strictly speaking, as there are ways to use just V6 units and other flashes (see below).

The advantage of the RF60 is that it has the ability to issue a true HSS burst (i.e., a very quick series of pulses that approach continuous lighting for a short duration).

With other flashes, you'd have to use the so-called "HyperSync" approach, i.e., fire them at full power so that their flash pulse is long enough (~1/125s) to illuminate the full frame while it is being exposed (which always takes a minimum of 1/180s, even if the true shutter speed is higher).

The HyperSync technique has the advantage that it works with any flash and the disadvantages that it requires full power shots and creates a graduated exposure (whereas a true HSS burst will give you an even illumination from top to bottom).

QuoteOriginally posted by mcgregni Quote
The V6 can't provide a radio trigger signal for the RF60 because the camera doesn't generate a signal it can recognize.
That is only true, if you don't make use of the capability of an V6 in Tx mode to be optically triggered by an on-camera flash.

An optically triggered V6, can use radio signals to fire off-camera RF60s or off-camera V6 units with compatible flashes attached.

QuoteOriginally posted by mcgregni Quote
There is no point in extra V6 receivers (in receiver mode attached to a slave flash) for HSS because there is no radio triggering available ...
One could use extra off-camera radio triggers as optical slaves to trigger attached flashes. I wouldn't recommend that, though, because the optical sensor is optimised for flash calibration and hence not nearly as sensitive as a regular optical slave.

However, extra V6 receives can be put to good use by either triggering them via an optically triggered V6 (that is so close to the on-camera HSS flash that it has no trouble detecting the latter), or by using my "HSS with manual gear only"-trick.
01-07-2016, 10:17 AM   #11
Pentaxian
mcgregni's Avatar

Join Date: Sep 2012
Location: Surrey, England
Posts: 2,602
Original Poster
QuoteOriginally posted by BrianR Quote
Thanks for the demo.

You probably already know, but the guide numbers for HSS at the various shutter speeds are in the back of the manual if you wanted to compare HSS vs ND filters.
Good point, thanks ... I guess the tables will give comparisons and an idea on power output. There would be a 2-3 stop loss when using the ND filter , but the power loss from higher than X-Sync speeds maybe causes even more? I take a look at some examples and post the figures ....
QuoteOriginally posted by BrianR Quote
No reason the teddy couldn't wear a bikini. Or make it a lingerie shoot and put the teddy in a teddy.
Sounds like I need to organise an HSS Teddy Bear Parade


QuoteOriginally posted by Class A Quote
Wow, very comprehensive description! ...... Glad it is working out for you so nicely!

Thanks, I hope it was interesting, and thanks to you for persuading me that the Cactus equipment was the way to go. I admit that for some time now I have been somewhat overwhelmed by the numerous threads we have with many descriptions of different 'workarounds' and techniques needed to get HSS without just buying more Dedicated System flashes.

I'm the sort of person who tends to think about it all first, and read the manuals, before putting it into practice, (now you know why I ask so many questions ), and it was very enjoyable to see it all come together and just work in a real situation without any messing around or experimentation.

I would say that, (as far as Cactus gear is concerned) my particular configuration and technique demonstrated here with the manual system working side by side with a P-TTL wireless system, is a fairly natural use of the equipment. The HSS Sympathy mode on the RF60 is key really, and as you said certainly provides the advantage over 'hyper-sync' approaches. And I was very pleased to find that even in direct bright sunshine, at 1/2000th sec, ISO 200, f5.6, I was only needing around 1/16th - 1/8th power from the Cactus unit as a result of using the Powersnoot device. So there is plenty of spare capacity for even more challenging HSS conditions.

My main concern about this approach was always the fact that it is sticking with the optical triggering technique, which is the Achilles Heel of HSS work outdoors in bright light. I played safe by working quite closely to the subject, and placing the lights so the sensors could both be facing the camera position, and I was really happy that the triggering was no problem at all, almost a 100% hit rate. This was aided of course by the Lightsphere diffuser and head angled up spreading the control flash around equally. Of course, there will eventually come limits to this reliability as distances increase or the 'line-of-sight' is compromised. But it was great to find a method of reliably triggering two slave flashes on two opposite sides from the camera in bright sun!.


QuoteOriginally posted by Class A Quote
We will be patient till you have organise the hot glamour model. If you can't organise a bikini as well, don't worry, we won't complain. Just don't forget the NSFW tag.
Hmmm, well I wouldn't want anyone to miss out on any HSS technique updates just because they're at work , so perhaps I should just stick with using soft toys .... !

Last edited by mcgregni; 01-07-2016 at 10:27 AM.
01-10-2016, 07:40 AM   #12
Site Supporter
Site Supporter
bobbotron's Avatar

Join Date: Jan 2015
Location: Ottawa, ON
Photos: Gallery
Posts: 2,639
Great write up mcgregni! Thanks for posting!
01-10-2016, 01:25 PM   #13
Pentaxian
mcgregni's Avatar

Join Date: Sep 2012
Location: Surrey, England
Posts: 2,602
Original Poster
Thanks! I'm glad you found it interesting. Those delay settings I reported on over at your thread worked a treat first time.
04-17-2016, 09:04 AM   #14
Loyal Site Supporter
Loyal Site Supporter
Mikesul's Avatar

Join Date: Sep 2009
Location: Phoenix, AZ
Posts: 6,295
This should be a sticky.
04-18-2016, 06:05 AM   #15
Pentaxian
mcgregni's Avatar

Join Date: Sep 2012
Location: Surrey, England
Posts: 2,602
Original Poster
Won't argue with that .... Do we need to start a petition? ... I'm glad you found the demo interesting. But could the forthcoming V6 upgrade consign optical HSS triggering with Cactus to history?
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
cactus, camera, flash, flashes, hss, light, lighting, mode, p-ttl, pentax, photo studio, strobist
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Cactus optical triggering w/ P-TTL HSS flash - settings bobbotron Flashes, Lighting, and Studio 32 12-31-2015 12:05 PM
Yongnuo YN560-TX Wireless Flash Controller vs Cactus Blacknight659 Flashes, Lighting, and Studio 65 12-18-2015 05:46 PM
Cactus v60 & rf60 v.s. PTTL-HSS - HELP! Please. amoringello Flashes, Lighting, and Studio 11 05-04-2015 07:56 AM
For Sale - Sold: Pentax AF 540FGZ Wireless P-TTL flash DEMO mint in box arm_jstp Sold Items 2 05-18-2012 09:09 PM



All times are GMT -7. The time now is 12:34 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top