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Old Sep 26, 2008, 7:45 AM   #1
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In an earlier thread, I was asking if anyone was able to get the Pentax K100D to flash sync at faster than 1/180sec.

QUESTION: Has anyone tried to use the built-in flash as a light trigger? I mean put the built-in flash up, but GOBO (block it's light from hitting the subject) and just use the light from the built-in flash to trigger a remote flash?

I am just really curious to see if I can flash-sync at faster than 1/180sec because of the flash balancing stuff I've been reading that describes how to use the sun as fill light & your flash as key light. But all their examples say to use 1/250sec.

A friend of mine has a cheap Digit-slave (which is a cheap light triggered flash). I think I'll have to walk over and borrow it to try this out to see if I can get my K100D to flash-sync faster than 1/180sec.

NOTE: When I have the Pentax K100D set to a shutter speed faster than 1/180sec and fire, the hot-shoe doesn't trigger.


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Old Sep 26, 2008, 8:15 AM   #2
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I believe if the internal flash is used it will limit the shutter speed to 1/180. If you really want to use fill flash at a speed faster than 1/180, consider a P-TTL flash that allows high speed sync. I have the Pentax AF360 and find it sufficient for most of my needs. Plus it can be found for about $170.
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Old Sep 26, 2008, 9:11 AM   #3
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Oh, yeah.

When I have my K100D in manual mode & I pop the flash, I do notice that it sets the sync to 1/180sec. Bummer.

As for buying a Pentax flash, I just can't bring myself to do it.

I just got a Vivitar 285HV & just love how much control it gives you so simply and quickly & I only paid $80 for it. (It also matches how I am using my K100D lately, which most of the time I have in manual mode with manual focus.)

I told myself I was going to use the money I saved (buying the Vivitar vs. Pentax flash) to buy a remote wireless trigger (which I've ordered and just waiting for) and then an umbrella, bracket to hold the flash & umbrella and a light stand. (The last three items I'm waiting on until I see how reliable the $20 wireless trigger is & until I figure out what I should be getting.)

I figure that I can get all of this for the price that I would have paid for the 360 & I get to start playing with a soft off-camera flash to boot!

I'm thinking that by the time I start getting into learning how to use this stuff, instead of buying a 360 or 540, I might just buy a used Nikon D70 to play around with balancing the sun for portrait shots outdoors.

But, if Pentax were to release a software update for their K200D to let the K200D trigger a flash at faster than 1/180sec (even if they had to disable the built-in flash) it would definately catch my attention & I would once again serious consider upgrading to the K200D over my K100D or jumping ship to Nikon. Which I put on hold because I wanted to learn about controlling light.

In fact, if they did this, they would probably end up selling me a Pentax K200D. I'd start using it. Maybe end up getting really involved in balancing light and then end up deciding that I'm really committed to the Pentax platform and then it becomes a no brainer for me to get the 540 (or whatever flash they have out then. <grin>) Then they'd end up selling me a new camera + flash instead of letting me keep thinking about going to Nikon. <frown>

Are you listening Pentax? <grin>

Take care,
Glen


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Old Sep 26, 2008, 2:25 PM   #4
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Hate to tell you, but it's a *hardware* limitation.

The reason the D70 works is because it uses a totally different hardware technique.

If you really want higher shutter speed, use HSS w/ a Pentax flash. I didn't think this was worth it and follow the ways of the strobist w/ an old SB28 flash on my K10D...

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Old Sep 28, 2008, 11:16 AM   #5
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This is an edit:

I apologize for the following wordy and less than useful post. I have not used a trigger/slave flash. I use the Nikon CLS system with results I expected from it. It is quite cost prohibitive for most but for my current situation I was able to acquire what was necessary to suit my interest in strobe photography.

--------------------------------------------------------------------------------------

I am not sure with the Pentax flash system if it does or does not have the high speed flash sync mode. I am sure it does. The P&S cameras and select Nikon dSLR's have 1/500th flash sync speed due to having an electronic shutter.

I am a work in progress with the world of strobe lighting with the Nikon system. I use the FP Sync Mode for outdoor shooting and actually keep it on all the time no matter where or what I shoot. This becomes especially useful for wildlife photographers that use long lenses for obvious reasons coupled with tele extender and/ or better beamer.

The use of flash can makemarginal shots, outstanding when you can master its nuances.

Here is a link that explains it better than any other site that I have found.

http://www.rpphoto.com/howto/view.asp?articleID=1026



Mahalo,

Tom



P.S. I am sure it can be done slaved but due to the equipment and flexibility I have with what I use I don't know much about it. I am sure in time it will become necessary to know this as well. The strobist is a good website to learn from as well.

http://strobist.blogspot.com/

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Old Sep 28, 2008, 10:42 PM   #6
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Hello vIZnquest!

Thank you so much for the reply.

I went to the link (rpphoto.com) right away and read through the entire story. The bit on how the newer flashes work to get high-speed sync really shed some light on the subject for me. (pun intended). Now I understand why those flashes (ie. Pentax 540 FGZ) can sync at high speed but manual flashes can't!

And I had just found out about the Strobist website. I actually had just finished reading through the 101 series last Friday and I am waiting for my wireless trigger so that I can start working my way through the 101 series to start figuring out some of this stuff.

Do you have anymore gems / websites to send my way. I'm just in this anxious mood to really learn how to get the most out of my camera now.

Take care, yours truly,
Glen


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Old Sep 30, 2008, 2:05 AM   #7
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I've got a K10 and Sigma 530 super. It has an assisted fast sync speed, but I'm not sure if I'm using it right. With it enabled on the flash I can sync up to 1/500 and beyond but every picture looks the same, no matter what the settings are (test shots were done in the basement) in reality they should be getting darker. When I turn the flash off at 1/500 it's pitch black (with room lights on) as expected, with it on, it's a perfect exposure... but it shouldn't be. So I don't really know what's going on here.


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Old Sep 30, 2008, 5:43 AM   #8
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You can do wireless HS flash with Sigma 530 DG Super and K20D and I think K10D. Your model camera and my DS are on the list of excluded cameras! Part of the reason I got a K20D.

Cheers

bb2


Edit: so says the manual! Am finding I can only use HS flash with the flash mounted on the camera at the moment. Still trying!
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Old Sep 30, 2008, 9:59 AM   #9
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Hello fisheye4,

I'm a newbie @ high-speed sync & I don't have a high-speed sync set-up to play around and test with . . . but it sounds like your Sigma 530 is doing exactly what it should be in the dark room.

Since the room is dark, there is only really one exposure to deal with. The flash exposure. Thus, even when you change the shutter speed, the camera is only dealing with the flash exposure, which it is able to configure itself to properly expose for. [NOTE: If you are trying to get the flash to be more or less powerful, I think you have to set the power manually. Don't know how it works on your flash, but that would be what I do with mine.]

My limited understanding to high-speed sync flash is this . . . (And please some one point out if I get this wrong! I'm just going by what I have been able to read on the web.)

High-speed Sync
---------------------
Can be used for many different reasons. It can be used to have better motion stopping ability or . . . the one I'm trying to get my head around is to be able to use the flash to balance the light from the sun. In otherwords, if you can set the right shutter speed (a fast one) and the right aperture setting, your flash will seem to be more powerful than the sun, so what you try to illuminate with your flash will become brighter than what is being illuminated by the sun. (Is that right?)

You can treat an exposure as two separate exposures. a) The exposure that is caused by the ambient light (which is controlled by the aperture and shutter speed), and b) The exposure that is caused by the flash (which can be controlled by turning up or down the power of your flash, the aperture size and also distance to the subject your flash is).

Now let's introduce a scenario. Let's say that I am taking a picture on a bright sunny day. I set my exposure manually to capture the blue in the sky. I figure out that at iso 200 & 1/125sec (my flash sync speed) that I must set my aperture to f22. But when I take this picture, the foreground stuff gets put into dark shade. [NOTE: And probably some good sun glare in there as well since I was playing with hiding the sun behind one of the ferris wheel cars.] Please see the attached experiment.



I got a blue sky, but the people (even though I used my flash at full power) are just not cutting it. They are too dull.

Now here's the thing. In order to get the sky to be blue, I had to set my aperture to f22. Now, that's really small. And with my flash's guide number = 120, if I take the Guide Number 120 and divide by the aperture (f22), I get 120 divided by 22 which then says I have to be about 5 feet away in order for my flash to register.

Now, I can't make my flash any more powerful (unless I move it closer to the subject) than full power. So the easiest thing to change would be the aperture size. What if I were able to set the aperture size to f8? Then if I do my calculation, Guide Number 120 divided by f8 = 120 / f8 = my flash becomes effective to 15ft? (Am I still on the right track guys?)

So I dial in f8, but low and behold, when I take that the shot at 1/125sec, the sky is over exposed and turns completely white.

Now, I think. Well. I've increased the light coming through the lens by three stops. (Going from aperture = f22 to aperture = f 8. So, of course the sky is going to be overexposed. I need to reduce the light coming through and I can't change my aperture now that I've opened it up to let my flash be more effective. The other thing I can change is the shutter speed. So in order to re-balance for the sky, I move it from 1/125sec to 1/1000sec. (Three stops less light.) (Am I still getting this right guys?)

So, I've added three stops of light by opening up the aperture to f8, but I go and take away those three stops by increasing the shutter speed to 1/1000sec. So in theory, my sky should turn out a similar exposure. But with the flash seemingly more powerful.

But here's the catch with my manual flash. I go to take the picture and . . . my flash doesn't go off. I can't high-speed sync with my manual flash (Vivitar 285HV). In order to actually have your flash go off at 1/1000sec, you need a flash that is designed to work with your camera at high-speed (Like the Pentax 540 FGZ), also, it sounds like your Sigma 530 DG is doing that for you as well!

So, I don't have a flash to test this out, but with my understanding of how you can use high-speed sync flash to balance with the sun, I would think the above settings would have worked.

If you take this further, you can actually underexpose the ambient light and make it less powerful than your flash unit. Then . . . your flash becomes the "key light" that you use for modelling your subject matter & the sun becomes a fill light. In the scenario above, I would guess that you could set the shutter speed to 1/2000sec or 1/4000sec but keep your aperture at f8. Then the sky would darken, and your flash would seem to illuminate the foreground and ferris wheel more. What's happening is that by changing the aperture and shutter speed, you can change how powerful your flash seems compared to the sun. NOTE: But then again, the above composition would be a poor choice to do this, since it would just make the shot look like it was taken on a poor day.

If anyone else can point out whether I am understanding this correct would greatly be appreciated. As I said . . . I don't have a high-speed sync flash to play around with this to see if I am understanding this correctly.

NOTE: I went back and re-read the manual for the Pentax 540 FGZ to see what they say about high-speed sync and they really don't say much in the manual about why you would want to use it or how you use it. Then again, that is the same way with camera manuals in general.

Take care,
Glen

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Old Sep 30, 2008, 1:29 PM   #10
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Hi Glen,

That was a great post, but I am no where near the level to be able to digest that. My understanding of high speed sync was related to this article on strobist

http://strobist.blogspot.com/2008/01...high-sync.html

I took my k200 and Sigma 530 super set to high speed sync out for a test run in the backyard. My understanding is that the hps is used to turn daylight into darkness, or to be able to use it as soft fill. The only way I can use it as soft fill is when I set it to manual at 1/64 and alter the camera settings apropriatly. Since the hsp setting on the sigma/pentax combo is really just a "dummy" version, it won't work like the nikon d70 would.

Here are my tests, I was able to get to 1/4000, f stop was around 9 and iso 200. With the flash off, it was pitch black. With it on, you could start to slightly see some table leg. I then slowed the shutter, 1/2000, 1/1000, 1/750 etc and here are the results.

http://farm4.static.flickr.com/3187/...b856f2e9_b.jpg

http://farm4.static.flickr.com/3256/...22dc0559_b.jpg

http://farm4.static.flickr.com/3209/...56e16ce5_b.jpg

http://farm4.static.flickr.com/3258/...2139c45c_b.jpg

http://farm4.static.flickr.com/3225/...923ee37c_b.jpg

sorry the subject is so boring, my model was on break :-)
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