Camera and flash 'limitations'

[inkista]

Originally Posted by jamiedennis

Thanks, I love the link - makes it very easy to understand...

Neil van Niekerk's Tangents website overall is pretty good, especially for on-camera flash. For off-camera, there's the Strobist.

[Zee Anna!]

I shoot with a Sony a700 and my max sync speed is 1/250. That bar that you're seeing in your images is your "curtain" meaning the shutter is closing too quickly to catch the light. To lower your shutter down below your sync speed you need to increase your aperture.

Try setting your iso to 100, and your shutter to it's max sync speed (1/250) then adjust your aperture as needed to get the desired image. You'll see more of a difference by changing your aperture.

[wulf]

Did you try any shots with the same set up but a lower shutter speed? Flash gives a very intense and fast burst of light and so changes the normal exposure rules. Typically you work out exposure based on the ISO level (light sensitivity), aperture (size of the hole for light to pass through) and shutter speed (amount of time to gather light). With the flash, the light is only on for a tiny fraction of a second so shutter speed is irrelevant as long as the shutter is open at the time the flash goes off. If you need to change exposure, you can still adjust ISO and aperture; the other variable is the intensity of the light, altered by changing the power of the flash unit and how near the subject it is positioned.

Wulf

ps. I have moved this to the lighting section - SYS is for when all you want to do is share your shots, not talk about the details of the technique involved

[jamiedennis]

Originally Posted by Zee Anna!

I shoot with a Sony a700 and my max sync speed is 1/250. That bar that you're seeing in your images is your "curtain" meaning the shutter is closing too quickly to catch the light. To lower your shutter down below your sync speed you need to increase your aperture.

Try setting your iso to 100, and your shutter to it's max sync speed (1/250) then adjust your aperture as needed to get the desired image. You'll see more of a difference by changing your aperture.

I will give this a shot... Thanks.

[jamiedennis]

Originally Posted by wulf

Did you try any shots with the same set up but a lower shutter speed? Flash gives a very intense and fast burst of light and so changes the normal exposure rules. Typically you work out exposure based on the ISO level (light sensitivity), aperture (size of the hole for light to pass through) and shutter speed (amount of time to gather light). With the flash, the light is only on for a tiny fraction of a second so shutter speed is irrelevant as long as the shutter is open at the time the flash goes off. If you need to change exposure, you can still adjust ISO and aperture; the other variable is the intensity of the light, altered by changing the power of the flash unit and how near the subject it is positioned.

Wulf

ps. I have moved this to the lighting section - SYS is for when all you want to do is share your shots, not talk about the details of the technique involved

I havent tried any shots with the "reverse" process yet... Ive been swamped with work. I will try this out either tomorrow (Thursday) or Friday, depending on how my work goes.

If I dont have time on either day, it will have to be next week some time - being the end of the month means Im super busy (Im a superintendent of a 96 unit building so I have a lot of back to backs to deal with.) When I get it sorted out I will post a few images of my outcome.

Thanks for help, I really appreciate it.

[ccting]

Originally Posted by scootermcq

Sure... you exceeded max sync speed for the camera. I don't know for that unit specifically, but it is probably limited to 1/200 or 1/250

Basically, the black line is the shutter closing cutting off the light from the strobe.

My D5100 does not allow me to go beyoung 1/200s even with external speedlight :_____(.
No flash channel commander.

[jamiedennis]

Sooo I managed to get the shot I wanted!!! Im thrilled with the results!

These are exactly how I shot them - I havent had time to process them... Hoping to fiddle with them tonight.

What does every one think so far???

Also, thanks to every ones suggestions for how to achieve this shot - I love them!!!

[ccting]

Originally Posted by jamiedennis

Sooo I managed to get the shot I wanted!!! Im thrilled with the results!

These are exactly how I shot them - I havent had time to process them... Hoping to fiddle with them tonight.

What does every one think so far???

Also, thanks to every ones suggestions for how to achieve this shot - I love them!!!

Dear Jamiedennis,
I am new to lighting so let me guess

a) kicker or rim light for both pics??
b) The background direct flash is the effect that we wish to get (i guess).
c) My question: How about the other lighting? hair light using direct flash, fill light using diffuse reflection or transmission, key light to add 3D effect, direct transmission for background light for pleasing grow..
d) i see reflection from hair at 2nd pic that causing flare..perhaps adjusting the light source or your hair?

I really don't know as i just started learning lighting "conceptually".

[jamiedennis]

Originally Posted by ccting

Dear Jamiedennis,
I am new to lighting so let me guess

a) kicker or rim light for both pics??
b) The background direct flash is the effect that we wish to get (i guess).
c) My question: How about the other lighting? hair light using direct flash, fill light using diffuse reflection or transmission, key light to add 3D effect, direct transmission for background light for pleasing grow..
d) i see reflection from hair at 2nd pic that causing flare..perhaps adjusting the light source or your hair?

I really don't know as i just started learning lighting "conceptually".

ok;
A. single light for both images, a 250W strobe W 75W "modeling bulb' inside it to give a faint idea of what I will capture. I put the light about 3 feet away from the model, at approx 45 degrees to the model and my self (think of a 45 pipe fitting - Im one end, the model is the middle, and the light is the end) and had the light aimed pretty much straight at the models face with just a sliver of light shining through to give the effect.

B. the effect I was after was a thin line of light around the models frame and everything else in darkness.

C. My uncle is a professional photographer and has been giving me 'theories' to try... He said to focus solely on 1 light source photos for a while and work on Chiaroscuro (Light on dark, on light on dark, etc)... I did another shot from this same day and it is a Chiaroscuro shot, but I dont know of the model will allow me to post it - shes partially wrapped in a feather boa and her back is exposed (shes very shy and a mom, I will talk to her about that image and see what she says about it... if I can post it, I will...)

So to answer your question - I havent focused on learning how to use those set ups yet, but I think once my uncle gets back from his trip he will give me a new 'theory' lesson and have me try something else. hahaha

D. The flare up was partially intentional - in some images, I like seeing sun dogs, solar flare, etc and I thought this would be a cool time to try achieving that in-studio. The effect worked pretty good - I just dont understand how I got the light to spiral (Im thinking it has something to do with the blades of my lens... I know the more blades you have, the smoother the 'bokeh' effect. And seeing as how this lens is a REALLY old lens, I think it might be the cause of the spiral)

Cool questions though - sorry I cant answer them better... Im also working towards learning the studio lighting aspect of photography.