Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
11-23-2009, 08:05 AM   #1
Forum Member

Join Date: Dec 2008
Location: Fishtown, Philly PA
Photos: Albums
Posts: 55
k100d Rear Sync set up

Hi all,

finally got a chance to practice shooting with my metz af 58-1 mecablitz and my k100d this weekend.

I was trying to do the dark nightclub type exposures with the camera and I do not think I had the rear-sync trigger set properly.

Basically, I was shooting at .5 to 1 second, 200iso, f4-5.6, camera in manual mode, flash off camera with whale tail and dedicated ttl cord attached, flash set to M mode with rear sync option, 1/4 to 1/16 power.

I got some cool shots, but I think the flash was firing when the shutter opened rather than closed--and my blurs (I think) occur AFTER the subject is illuminated by the flash, not before.

So, my question is: is there a setting in the k100d that I have to turn on to get rear sync or is the camera always sending this signal and the flash just uses it if you have that mode selected on the flash?

For all I know, I have this working, but it sure seemed to me that the flash was triggering when the shutter opened rather than as it closed--and I think the pictures I have and how they are blurred show this to be the case...



Last edited by steveeboy; 11-23-2009 at 08:10 AM. Reason: adding photo
11-23-2009, 08:12 AM   #2
Forum Member

Join Date: Dec 2008
Location: Fishtown, Philly PA
Photos: Albums
Posts: 55
Original Poster
This shot indicates what I mean with the blur and such...

11-23-2009, 08:41 AM   #3
Veteran Member

Join Date: Jan 2008
Location: Ste-Anne des Plaines, Qc., Canada
Posts: 2,014
Just a small problem: no pictures.
11-23-2009, 04:58 PM   #4
Arpe's Avatar

Join Date: Sep 2006
Location: New Zealand
Photos: Gallery | Albums
Posts: 4,372
Did you set rear curtain on the camera or on the flash?

And no picture showing.

11-24-2009, 06:52 AM   #5
Forum Member

Join Date: Dec 2008
Location: Fishtown, Philly PA
Photos: Albums
Posts: 55
Original Poster
I cannot seem to get the image posted,

I had the flash set to rear sync, but I do not think I had the k100d right.

my additional research indicates that the metz defaults to regular sync if you don't have the set up in the camera right.

When I had the 1 sec shutter the flash was definitely firing when I depress the shutter not after the shutter had been opened and was closing.

I found some info that indicated if you have the k100d on manual and a pentax flash the camera will automatically switch to p-ttl when you push shutter down.

Just asking if anybody knows what settings the k100d should be on to get the rear sync to work with the metz af 58-- or in general.
11-25-2009, 08:01 AM   #6
Forum Member

Join Date: Dec 2008
Location: Fishtown, Philly PA
Photos: Albums
Posts: 55
Original Poster
k100d rear sync PROBLEM SOLVED

alright, played around some more last night and here's the deal...

the metz must be set to p-ttl for the rear sync to work.

also, the k100d cannot tell the flash when to fire the rear sync unless you first set it to a pre-set auto mode like portrait.

If you have the camera set to manual, the auto flash mode is not selectable so the camera doesn't seem to send the proper signal to the flash and the flash just fires at the first shutter rather than the trailing curtain signal--even if you have the af58 set to rear sync, if it does not get the proper signal it defaults to front curtain sync and fires when the shutter opens.

So, you have to set a mode on the k100d that allows the selection of auto flash--if you have the camera in M you will see that auto flash is grayed out and not selectable. When you first set it to a mode that allows auto and THEN switch to manual mode, it seems that the camera then will start talking to the flash via the dedicated ttl cord.

AFTER you get them talking, you can switch the k100d into whatever mode you want -m, tv, av, etc, and it will fire the flash on the rear sync as long as you leave the flash set to p-ttl and rear sync on...

so, to get it to work I did the following:

Flash--p-ttl, rear sync on
camera--set to portrait auto mode, flash on auto.
wait a sec and they start talking to each other.
switch camera to desired mode-in this case M.

I was doing this to get the nightclub pictures where you use a slow shutter to catch the ambient light and then fire the flash on the rear curtain to light the subject and get the blur/trails leading to the properly lit subject.

so, camera set manual .5-1sec exposure, f4 or so, flash on rear sync p-ttl.

You cannot adjust the power with the metz as you would in manual mode--1,1/2,1/4,1/8th power etc., but you can adjust via EV stops to get the same sort of adjustability and dial in the exposure.

One other thing, when I first got the set up working the flash was firing a pre-flash when you depressed the shutter to take a meter reading and then firing on the rear sync trigger for the real exposure.

However, I also realized as I was messing with this that I was not getting a focus assist beam from the flash unit and fixed that by setting the camera focus mode to AF.S rather than AF.C.

When I changed that setting, the focus beam started working AND the camera no longer fired the pre-flash when I depressed the shutter.

I am not sure if that the change with the focus beam setting changed that or if it was some other communication, but I now had a camera and flash that was properly set up to take the sort of night club shots you see on sites like and elsewhere without that pre-flash( which might be an issue if people saw it, assumed the photo was taken, and moved during the long shutter exposure and then got caught by the rear sync flash .5-1 second later)

once more on the set up:

sigma 28mm 1.8 ex dg
metz af 58 meca blitz
camera on manual .5-1sec, f4, ISO 200
dedicated p-ttl cord
gary fong whale tail diffuser

the key is to have the flash rear sync on and set to p-ttl (on the metz), set the camera to a pre-set scene selection that allows auto flash (such as portrait mode), get the camera and flash talking, and THEN set the camera to manual and shoot as normal.

Adjust the flash power with the EV compensation on the flash to get it how you want.

I have not messed around much with the camera to see if you can control the flash settings and such with the camera controls, that will be next.

I haven't used the sigma 28 much and had actually thought about selling it, but I must say that it seems perfect for this type of situation and seems to focus faster/better than my pnetax da 14mm 2.8 in the dark. Also, the 14mm is REALLY wide and you have to get too close to get properly framed images of people. The Sigma seems just right.

see if these links work...

the front sync set up example looks like this:

the properly working rear sync example looks like this:

Last edited by steveeboy; 11-25-2009 at 08:03 AM. Reason: fix photo links

  • 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!
camera, flash, k100d, k100d rear sync, mode, shutter, sync, tripod
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
Rear sync trishytee Pentax Camera and Field Accessories 9 03-29-2010 01:41 PM
Can the Sigma EF530 DG Super be set to rear curtain sync? ismaelg Pentax Camera and Field Accessories 1 11-26-2009 07:53 AM
option for rear curtain sync on k100d with on-board flash??? eclipsed450 Troubleshooting and Beginner Help 2 03-04-2009 10:16 AM
Rear curtain sync trishytee Pentax Camera and Field Accessories 5 02-23-2009 07:28 AM
rear sync trishytee Pentax Camera and Field Accessories 10 02-08-2009 12:22 PM

All times are GMT -7. The time now is 11:13 PM. | See also:, 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?
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]