Go Back   Steve's Digicams Forums > Digital SLR and Interchangeable Lens Cameras > Pentax / Samsung dSLR, K Mount Mirrorless

Reply
 
Thread Tools Search this Thread
Old Jun 23, 2008, 8:22 AM   #1
Junior Member
 
Join Date: Jul 2006
Posts: 29
Default

Hi, I havn't posted for quite a while but I have a couple of questions that I hope someone can help me out with.

I have an Pentax *istDL2 DSLR and want to run an external flash. I also have, from my old Canon 35mm SLR kit, a Vivitar 3700 flash unit with a Canon dedicated module. What I would like to know is whether I can use the Vivitar unit in manual mode on my Pentax camera even though it's got the Canon dedicated module attached.

The two pins on the flash's hotshoe that comunicated with the Canon camera do not make contact with any pins on the Pentax camera, so only the centre trigger pin will make any contact on the Pentax's hotshoe. Does this mean that the flash will work in manual mode or will it not work at all because it is trying to comunicate with the camera unseccessfully through the other two pins.


Also, regarding the trigger voltage. I have measured the trigger voltage on the Vivitar flash to be 9.1v. Is this safe to use on the *istDL2 or is it a bit risky. Obviously, I'd rather err on the side of caution.


Many thanks for any help offered.

Regards

Russell
RussellS is offline   Reply With Quote
Sponsored Links
Old Jun 23, 2008, 8:53 AM   #2
Administrator
 
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378
Default

I've seen some users report that Pentax told them 30 volts on some of the earlier Pentax models and 25 volts for the newer K series dSLR models. But, I haven't seen anything official from Pentax. So, you may want to send them a note and ask. I doubt a flash with a trigger voltage under 10 volts is going to cause a problem.

You'd probably need to use it as a manual flash, setting the camera and flash to match for aperture and ISO speed. Most older flash models are not going to be able to communicate properly with modern digital cameras (understanding the communications needed for the metering preflash, etc.), even if you swapped out the foot for a newer one designed for Pentax.

Some dedicated flashes won't work right at all (always fire at full power, or don't fire at all) when used with digital. But, if it's got manual settings (or Auto ranges where you set the Aperture and ISO speed to match the camera), then you could probably use it that way using manual exposure on the camera (most will fire when the center pin and outside shoe are shorted, which the camera is probably doing when taking a photo).

JimC is offline   Reply With Quote
Old Jun 23, 2008, 8:54 AM   #3
Junior Member
 
Join Date: Jul 2006
Posts: 29
Default

Sorry everyone, I've just realised that I've posted in the wrong forum.

I shall repost in the Pentax DSLR forum.



Consider this thread closed.
RussellS is offline   Reply With Quote
Old Jun 23, 2008, 8:55 AM   #4
Administrator
 
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378
Default

I moved it for you.

JimC is offline   Reply With Quote
Old Jun 23, 2008, 11:47 AM   #5
Senior Member
 
jachol's Avatar
 
Join Date: Aug 2006
Location: NW. England
Posts: 1,201
Default

Hi Russell,

This is a useful reference site when looking at third party flashes ... Jack.

http://www.botzilla.com/photo/strobeVolts.html
jachol is offline   Reply With Quote
Old Jun 23, 2008, 2:55 PM   #6
Junior Member
 
Join Date: Jul 2006
Posts: 29
Default

jachol wrote:
Quote:
Hi Russell,

This is a useful reference site when looking at third party flashes ... Jack.

http://www.botzilla.com/photo/strobeVolts.html
Thanks for the reply,

I've already checked out that site and my trigger voltage measurements are the same as reported there in that the Vivitar has a trigger voltage of 9.1v

What it doesn't say though, and what I was after info about, was whether 9.1v is likely to do any damage to my *istDL2 camera.

Is there any official word from Pentax as to what the maximum safe trigger voltage is?


Regards

Russell


PS. Thanks Jim for moving the post for me.
RussellS is offline   Reply With Quote
Old Jun 24, 2008, 4:12 AM   #7
Senior Member
 
jachol's Avatar
 
Join Date: Aug 2006
Location: NW. England
Posts: 1,201
Default

RussellS wrote:
Quote:
jachol wrote:
Quote:
Hi Russell,

This is a useful reference site when looking at third party flashes ... Jack.

http://www.botzilla.com/photo/strobeVolts.html
Thanks for the reply,

I've already checked out that site and my trigger voltage measurements are the same as reported there in that the Vivitar has a trigger voltage of 9.1v

What it doesn't say though, and what I was after info about, was whether 9.1v is likely to do any damage to my *istDL2 camera.

Is there any official word from Pentax as to what the maximum safe trigger voltage is?


Regards

Russell


PS. Thanks Jim for moving the post for me.
Hi Russell,

I think most people on this board accept the 30 volt figure, though there is some uncertainty as to where this figure came from, I have seen it said that it was a Pentax source. I just checked my own Pentax AF400 FTZ but it doesn't help much trigger volts on that is 3.5. If it gives you more confidence I can tell you that when I first got my K100D I shot several pics with an old thyristor flash Jessops 240 ABZ, until I found that was triggering at 275 volts, the camera survived that episode, so I'd be quite happy to use one that triggers around 9.0 volts. ... Jack
jachol is offline   Reply With Quote
Old Jun 24, 2008, 6:13 AM   #8
Junior Member
 
Join Date: Jul 2006
Posts: 29
Default

Hi Jack,

Thanks for the information. I have sent an email to Pentax in the hope of getting some clarification, but whether I get a response or not I'll have to wait and see.

Having done a bit of searching, it appears that the ISO standard for trigger voltage is a max of 24v. However, Canon still say a MAXIMUM of only 6v on the Powershot & EOS cameras (although AFAIK even that is not officially written down anywhere).

It's all very confusing. I don't know why the maximum SAFE triggering voltage is not specified in the technical specifications section of the camera user guide.


Anyway, thanks once again for the reply,

Russell
RussellS is offline   Reply With Quote
Old Jun 24, 2008, 7:06 AM   #9
Senior Member
 
jachol's Avatar
 
Join Date: Aug 2006
Location: NW. England
Posts: 1,201
Default

RussellS wrote:
Quote:
Hi Jack,

Thanks for the information. I have sent an email to Pentax in the hope of getting some clarification, but whether I get a response or not I'll have to wait and see.

Having done a bit of searching, it appears that the ISO standard for trigger voltage is a max of 24v. However, Canon still say a MAXIMUM of only 6v on the Powershot & EOS cameras (although AFAIK even that is not officially written down anywhere).

It's all very confusing. I don't know why the maximum SAFE triggering voltage is not specified in the technical specifications section of the camera user guide.


Anyway, thanks once again for the reply,

Russell
Russell,

If you do get info out of Pentax, please post anything you get, I'm sure the folks here

would welcome that sort of input.

Perhaps I'm being cynical, maybe they expect you to buy the flash currently designed

for present day cameras, and that is why the safe trigger voltage isn't published.

Actually the model of flash I have, mentioned earlier would be ideal for you, as it is a

TTL model, I'm sure Pentax changed to P-TTl after the ist models. They do come up

occasionally on Ebay, at not to bad a price. I was fortunate to get the cord and

adaptorin the deal for off camera use in thedeal, which aren't cheap items. ... Jack.
jachol is offline   Reply With Quote
Old Jun 24, 2008, 10:15 AM   #10
Junior Member
 
Join Date: Jul 2006
Posts: 29
Default

Well, I've taken the plunge and tried my Vivitar 3700 flash on the *istDL2 and it works fine. Obviously, I've got to set the shutter speed and aperture on the camera manualy, but that's fine. I've had this Vivitar flash for years and have always been very pleased with it's performance which is why I wanted to continue using it having gone digital.


On a side issue, I have now had an official response back from Pentax regarding the safe trigger voltage as quoted below.

Quote:
Dear Sir/Madam,

Thank you for your enquiry.

The maximum voltage that the camera can handle is 30v.

I hope that your question has been answered to your satisfaction. Should you have further questions regarding this matter, please do not hesitate to contact us again.

When replying, please make sure this email is included.

With kind regards,


Jim Reinders
Pentax Digital Camera Support Team



Your Email:

I have a Pentax *istDL2 digital SLR and would like to use a manual non-dedicated flash unit on the hotshoe. What I would like to know is what is the maximum safe flash trigger voltage that will not damage the camera.

Many thanks

Russell Spearing
I shall post a seperate thread in this forum with this information for all to see.


Regards

Russell
RussellS is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 6:02 AM.