Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
04-20-2011, 12:15 PM   #1
Senior Member
bluebronco's Avatar

Join Date: Feb 2008
Location: Iowa
Photos: Gallery | Albums
Posts: 170
Manual Flash Question(s)

Hello,

I have a K20D with a Promaster EDF7500 P-TTL flash gun. The P-TTL works great.
I also recently purchased the Cactus Wireless Flash Transceiver V5 Duo. I realize that they do not support P-TTL.
I also have an older Vivitar Auto Thyristor 550FD to use as a manual flash along with the Promaster in manual mode.

The problem, I don't quite understand how to effectively change the light output on the Vivitar. The Promaster has a digital interface and is very easy to understand. Here is the back of it. I found this image online. It is the same as the one I have:



Can someone explain what each slider does and how to change flash output? When I use the Vivitar, the image is totally blown out by the flash.
I guess I am a child of the "electronic age!"

Thanks

04-20-2011, 12:49 PM   #2
Senior Member
metalmania's Avatar

Join Date: Feb 2011
Posts: 253
My Metz 36C2 is similar. The A1 and A2 is for high and low output separately. You can also use a small aperture at the same time. Just my 2 cents.
04-20-2011, 01:00 PM   #3
Pentaxian




Join Date: Feb 2009
Location: Alameda, CA
Posts: 3,194
You can't change the output of the Vivitar 550FD in manual mode. There is no ratio setting. It always fires at full power in manual.
04-20-2011, 01:05 PM   #4
Senior Member
metalmania's Avatar

Join Date: Feb 2011
Posts: 253
QuoteOriginally posted by SOldBear Quote
You can't change the output of the Vivitar 550FD in manual mode. There is no ratio setting. It always fires at full power in manual.
Guess the Metz is different then. There are 3 "A" locations with different colors on Metz with different output. Please disregard my first reply.

04-20-2011, 01:16 PM - 1 Like   #5
Pentaxian




Join Date: Feb 2009
Location: Alameda, CA
Posts: 3,194
QuoteOriginally posted by metalmania Quote
Guess the Metz is different then. There are 3 "A" locations with different colors on Metz with different output. Please disregard my first reply.
Power ratios in manual and aperture settings in auto are two different animals.

The OP asked how to set power ratio (full, 1/2, 1/4, ....) in manual mode.

The "A" settings on your Metz are aperture settings in auto mode.

You can use the A settings to trick the flash into emitting less power. But unlike with manual power ratio settings, the result is unpredictable.
04-20-2011, 01:16 PM   #6
Site Supporter
BigDave's Avatar

Join Date: Sep 2010
Location: Hudson Valley, NY
Photos: Gallery | Albums
Posts: 1,443
I have not used this flash personally, but the set-up is common to most flashes of its like.

A1 and A2 are automatic settings. The sensor on the flash will control the power output, irrespective of the camera. Just set your ISO, place the switch on one of the settings and set your aperture to the recommended f-stop. The sensor should do a good job, as long as nothing gets between the flash and the subject. Just make certain you are in the distance range for the setting (for instance in the picture, the A1 position has a range of 5-40 feet and at the ISO 200 it is set on, you need to use f2.8).

When you switch the flash to the M setting, as stated, it will fire full power all of the time. However, when in the M setting, the flash should show, in the window between feet and meters, which f-stop to use at a particular distance. It will help to have a distance scale on your lens to help calculate the exposure then. If it is being used as a fill light flash, and it is sitting in one spot/location, then you can measure the distance from the flash to the subject and use this distance to calculate exposure. These little flashes can work very nicely as a fill flash or highlight flash. Once you know where it needs to go, measure the distance and put it there everytime.

Good luck with it!
04-20-2011, 01:21 PM   #7
Senior Member
metalmania's Avatar

Join Date: Feb 2011
Posts: 253
QuoteOriginally posted by SOldBear Quote
Power ratios in manual and aperture settings in auto are two different animals.

The OP asked how to set power ratio (full, 1/2, 1/4, ....) in manual mode.

The "A" settings on your Metz are aperture settings in auto mode.

You can use the A settings to trick the flash into emitting less power. But unlike with manual power ratio settings, the result is unpredictable.
Thanks. I learned something today.
04-20-2011, 01:29 PM   #8
Senior Member
bluebronco's Avatar

Join Date: Feb 2008
Location: Iowa
Photos: Gallery | Albums
Posts: 170
Original Poster
QuoteOriginally posted by metalmania Quote
Thanks. I learned something today.
So did I!

Thanks for the info.

04-21-2011, 09:29 PM   #9
Veteran Member
sterretje's Avatar

Join Date: Dec 2008
Location: Roodepoort, South Africa
Photos: Gallery | Albums
Posts: 3,534
I assume SOldBear is right about the manual mode (I don't have the flash or the manual so I can't say). So your only way to influence the effect of the flash is by selecting aperture and ISO on the camera.
04-21-2011, 09:37 PM   #10
Site Supporter
BigDave's Avatar

Join Date: Sep 2010
Location: Hudson Valley, NY
Photos: Gallery | Albums
Posts: 1,443
Aperture, ISO and distance from the subject to the flash, don't forget that last one. If this is a secondary flash, then you have a great deal of control, assuming the room/shooting area is big enough!
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!
camera, change, flash, image, output, p-ttl, pentax help, photography, promaster, vivitar
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Manual lens question pdxbmw Pentax DSLR Discussion 9 10-18-2010 04:52 PM
Basic Pentax K-x, hot-shoe, flash, flash bracket, wireless question MrPetkus Flashes, Lighting, and Studio 5 04-27-2010 10:57 PM
Advanced high speed or manual flash question StarDust Flashes, Lighting, and Studio 3 11-28-2009 04:45 AM
Yet another manual lens question! sherib Troubleshooting and Beginner Help 4 10-28-2009 07:00 PM
Owner's Manual Question opfor Photographic Technique 5 06-19-2009 02:21 PM



All times are GMT -7. The time now is 11:06 AM. | See also: NikonForums.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