Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
12-05-2019, 08:17 AM   #1
Junior Member




Join Date: Jan 2012
Location: Outlook, Sask.
Photos: Albums
Posts: 46
M and K lens with cactus trigger

Hi
I have K3 as well as some old K and M lenses. I'm trying to use my Cactus V6ii triggers to fire my flash with these lenses. I know the pTTL mode doesn't work, but I thought if I set the cactus trigger to manual on my camera I should be able to adjust my flash level. This doesn't seem to work the flash will fire, but only on the highest power. Am I missing a setting somewhere. If I put my speedlight directly on the flash and set it to manual I can adjust the level, I'm not sure what the difference is.
Thank you
Evan

12-05-2019, 08:51 AM   #2
Otis Memorial Pentaxian
Loyal Site Supporter
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 35,589
It will help if you share the brand and model of the speedlight as well as what is being used as the receiver to trigger the flash.


Steve
12-05-2019, 09:06 AM   #3
Junior Member




Join Date: Jan 2012
Location: Outlook, Sask.
Photos: Albums
Posts: 46
Original Poster
Hi
Steve, I using the Cactus V6ii, both as triggers and receivers. My flash is a Metz 52-AF1.
12-05-2019, 09:24 AM   #4
Otis Memorial Pentaxian
Loyal Site Supporter
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 35,589
QuoteOriginally posted by sjovolde Quote
My flash is a Metz 52-AF1.
OK...so the flash is P-TTL compatible and not a speedlight per se.


Steve

12-05-2019, 09:54 AM   #5
Loyal Site Supporter
Loyal Site Supporter
pschlute's Avatar

Join Date: Mar 2007
Location: Surrey, UK
Photos: Gallery
Posts: 3,894
QuoteOriginally posted by sjovolde Quote
I have K3 as well as some old K and M lenses. I'm trying to use my Cactus V6ii triggers to fire my flash with these lenses


I think it is due to the fact that even in manual flash mode the cactus triggers still rely on the Pentax P-TTL protocol to work. The camera "thinks" there is a flash unit on the hotshoe (the cactus transceiver) eg... you press the shutter button .... camera wants to fire a preflash/measure the preflash/decide on an output/tell the flash to fire that output. What the Cactus unit on the camera does is read the instruction to fire the main flash, but instead of the Pentax calculated amount, it sends the Manually set amount 1/1 - 1/128 to the receiver unit. With the cactus V6II and a modern lens this process definitely occurs. Anyone who has tried to use a flash meter will attest to that (flash meter registers on the pre-flash not the main one).

Now if you add a M or K series lens into the mix... because the camera cannot know the FL or focus distance, or aperture, P-TTL will not work. I think this is the problem you are seeing. Please correct me if I am wrong.

Answer is to set the power output on the flash directly in Manual Flash mode. The cactus units will then operate as simple dumb triggers
12-05-2019, 10:00 AM   #6
Junior Member




Join Date: Jan 2012
Location: Outlook, Sask.
Photos: Albums
Posts: 46
Original Poster
Peter
Thank you for the explanation on how the system works. I didn't realize that the cactus system still relies on the P-TTL protocol to work. That explains why a few other things I have observed with system. In general for what I do it works well.
12-05-2019, 12:07 PM   #7
Loyal Site Supporter
Loyal Site Supporter
pschlute's Avatar

Join Date: Mar 2007
Location: Surrey, UK
Photos: Gallery
Posts: 3,894
There are a number of Cactus users on this forum who know the system better than me, so hopefully they will correct me if i am wrong here.
12-06-2019, 05:07 AM   #8
Pentaxian
Class A's Avatar

Join Date: Aug 2008
Location: Wellington, New Zealand
Posts: 10,623
What @pschlute wrote is correct.

However, it shouldn't be necessary to resort to "dumb triggering".

It should be possible to still retain remote power level control by configuring the V6II to work as a "single pin trigger".

Try setting the camera flash system on the V6II trigger (the one that is mounted to the camera) to "OTHER" instead of "Pentax" or "Auto".
This should remove the option to use P-TTL features but bring back the option of remote power-level control when working with a manual lens.

12-06-2019, 10:07 AM   #9
Junior Member




Join Date: Jan 2012
Location: Outlook, Sask.
Photos: Albums
Posts: 46
Original Poster
Thanks Class A
I'll give that a try today if I get a chance. I'm still trying to understand a few more features of these cactus triggers, such as how to get rear sync to work as well as the delay and multi flash modes.

Evan
12-25-2019, 05:57 PM   #10
Pentaxian
Aaron28's Avatar

Join Date: Jan 2015
Location: Huntsville, Al
Posts: 4,302
this is with the cactus v6 so the v6ii maybe slightly different although I would do the same thing.....using a m42 lens on a k-50...set the TX unit to manual.....mounted a af360fgz on RX unit that is set to manual...set up flash in auto mode setting f/x.x and xxx iso to what is on camera (should work just as well if using a manual setting on flash 1/4, 1/8, etc)…..basically the cactus units are now simple triggers i am not concerned with me controlling the flash power but relying on the auto mode of the flash...the following is 3 frames using said set-up as it is an experiment to use the cactus v6 for use with some leaf shutter TLR and rangefinders with pc sync ports and check the reliability of using the flash in auto mode with film....seems I can trust a good exposure on film using the auto mode....not quite what yer asking about but I see them as ordinary triggers in this fashion using any non 'a' lens



as far as delay for 2nd curtain I set the delay time on the TX to correspond to shutter time that is set and in test shots that seems to work......i.e. 1/5 on camera.....0.2sec on TX delay time

Last edited by Aaron28; 12-25-2019 at 07:11 PM.
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, fire, flash, lens with cactus, lenses, level, lighting, photo studio, strobist
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: Pentax AF540FGZ,Sigma EF530DG Super,Cactus RF60 flashes,Cactus V6II and V6 triggers G and T Sold Items 3 11-05-2018 10:41 PM
HSS with Flashpoint Evolv AD200 and Godox R2 Trigger and Cactus v6 ii combo help sureshgvv Flashes, Lighting, and Studio 8 08-15-2018 02:50 AM
K-1, Cactus V6 ii, and Cactus RF60X--- no TTL even after firmware upgrade? funkythiru Flashes, Lighting, and Studio 47 07-10-2018 08:32 AM
For Sale - Sold: Pentax K1+50mm 2.8 macro+cactus flash and cactus trigger. wdh1974 Sold Items 7 03-11-2017 08:55 PM



All times are GMT -7. The time now is 06:02 AM. | 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