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first attempt at off-camera lighting...

PostPosted: Thu Aug 09, 2007 8:19 pm
by mattyjacobs
... and I'm lusting after a second speedlight! Or some reflector thingies.

This was literally one of the first shots I took - I set the aperture to 2.8, dialled the flash down to 1/32 or something, and fired a few shots, adjusting the shutter speed as I went, til I got a nice exposure.

Then fiddled a bit in photoshop.

help please? (she's my missus - 32 weeks pregnant, just home from 8 hours of nursing, so be kind!)

Image

PostPosted: Thu Aug 09, 2007 8:23 pm
by Thommo
really nice lighting, but i think it would suit a more serious expression.

but still i like it.


also afaik shutter speed plays VERY little role in exposure for flash unless you are trying to capture ambient light. So in this case if your exposure was off you would have to dial down the flash some more or use a smaller a

PostPosted: Thu Aug 09, 2007 8:25 pm
by mattyjacobs
yeah, I've sort of noticed that you can balance shutter speed with flash power to either black out the background, or get some nice ambient light, as well as bringing out more detail in the face/detail area. I think I'll be pretty much setting the aperture to get good focus on the details I want (too tight in the above image), and balancing flash power with shutter speed...

PostPosted: Thu Aug 09, 2007 10:13 pm
by Reschsmooth
Hey Matty

I am no expert, but here are my comments:

1. The flash looks like it was to the side of her face? The harsh shadows from her nose give this away. This can be fine, but for a flattering portrait, you may want to move the flash more to the front - say 45 degrees?
2. The wide aperture of 2.8 creates a really shallow depth of field, evidenced by her hair being out of focus. You can go for a 5.6 aperture to get more DOF and increase the flash to 1/16.
3. If you have a white hard surface (esky lid or a windscreen shield) you can place it (somehow) to her left side of face to reflect a bit to the off flash cheek. This will balance the light a bit.

Bear in mind that a flash gun will be a very small source of light and will create harsh shadows regardless of how you set it up.

Having said that, it is a great first effort. You will soon get very addicted to portrait lighting.

OT - I ordered some coffee from Hazel - hopefully it gets here tomorrow!

PostPosted: Fri Aug 10, 2007 12:13 am
by ozonejunkie
I am in no position to offer any technical advice, but there is just something about this image that I really like. I keep getting drawn back to it, and I have absolutely no idea why!

I like. :D

Tristan

PostPosted: Fri Aug 10, 2007 12:37 am
by jamesw
mattyjacobs wrote:yeah, I've sort of noticed that you can balance shutter speed with flash power to either black out the background, or get some nice ambient light, as well as bringing out more detail in the face/detail area. I think I'll be pretty much setting the aperture to get good focus on the details I want (too tight in the above image), and balancing flash power with shutter speed...


nice effort with your shot!

im not sure if you grasped what was said, so i might re-iterate, and perhaps get a bit more in depth about the flash power / shutter speed / aperature relationship.

with your flash, you are typically getting somewhere between 1/800th to 1/1000th of a second for the flash burst, while on full power. as you dial flash power down, the flash burst duration gets shorter.

what that means is that you can basically push your shutter speed to the point that it is the same as flash duration, and your exposure will not be affected. you are simply cutting the ambient light out of your image.

also keep in mind that you are realistically only going to want to sync between 1/250 to 1/1000 so you shouldnt run into problems with your shutter speed affecting the flash component of exposure.

aperature does have an effect on your exposure, obviously, as aperature is the amount of light allowed to hit the piece of film / sensor. so as you open up or stop down your aperature, you are either increasing or cutting down your flashes' power (as well as ambient light).

so if you intend to choose an aperature soley for DoF reasons, without taking into consideration the flash exposure, you are going to need to be dialing your flash power up or down to get the level of light that you want.

that is because all the shutter speed does in these situations is control ambient light...

hopefully that is a reasonably clear explanation. it took me a little while to get my head around it.

PostPosted: Fri Aug 10, 2007 1:52 am
by Thommo
jamesw wrote:
what that means is that you can basically push your shutter speed to the point that it is the same as flash duration, and your exposure will not be affected. you are simply cutting the ambient light out of your image.


In theory you can do this but due to the nature of the shutter the fastest you can sync is 1/250th to 1/500th ( i think)

PostPosted: Fri Aug 10, 2007 8:39 am
by gstark
James,

jamesw wrote:what that means is that you can basically push your shutter speed to the point that it is the same as flash duration, and your exposure will not be affected. you are simply cutting the ambient light out of your image.

also keep in mind that you are realistically only going to want to sync between 1/250 to 1/1000 so you shouldnt run into problems with your shutter speed affecting the flash component of exposure.


Is that really what you wanted to say?

While exposure might not be affected at these higher speeds, flash sync most certainly will be, and you'll most likely get dark bands from the shadows of the shutter curtains as they open too late or close too early because you're operating outside the camera's stated sync speed.


Thommo wrote:
jamesw wrote:
what that means is that you can basically push your shutter speed to the point that it is the same as flash duration, and your exposure will not be affected. you are simply cutting the ambient light out of your image.


In theory you can do this but due to the nature of the shutter the fastest you can sync is 1/250th to 1/500th ( i think)


It actually depends upon the camera and the effect that you want to see as your end result.

Most cameras today will sync between 1/15 and 1/200. Some will go to 1/250 or 1/500. The D70, with a bit of application (of gaffer tape) can sync faster.

But often, a faster sync speed is exactly what you do not want.

Matty, to balance your flash and the ambient light, try this technique ...

1: meter the ambient light conditions for the background that you're wanting to capture. Get an EV reading, and look at the equivalent shutter speed/aperture combinations.

2: from those, choose one that has a shutter speed within your camera's sync speed range. Say 1/125 @ f/8

3: Now set your flash to that power setting (f-stop) as indicated, or perhaps a half-stop to a stop below. For the above example, say f/5.6 - f/6.3.

4: Use that as your starting point, shoot, and then chimp your histogram, ensuring that you're not falling off one end or the other.

...

Getting back to this image, I too would like to see, first of all, a softer light source, and then, have it moved around so that it is less side-on to the subject. Put a sock on it, and hold it at about arm's length, to your left. (Do you have one of Poon's socks? )

Good starting point ... and a lovely model.

PostPosted: Fri Aug 10, 2007 10:45 am
by Hybrid
If you're trying to grasp some of these concepts, a there's a really good video to watch here: http://www.studiolighting.net/digital-p ... ter-speed/

PostPosted: Fri Aug 10, 2007 10:48 am
by Reschsmooth
Another source of product-flog based information (which isn't too bad) can be found here. It primarily/solely deals with brollies cause that's what they sell. Still reasonable information, nonetheless.

Cheers

PostPosted: Fri Aug 10, 2007 10:53 am
by jamesw
gstark wrote:James,

jamesw wrote:what that means is that you can basically push your shutter speed to the point that it is the same as flash duration, and your exposure will not be affected. you are simply cutting the ambient light out of your image.

also keep in mind that you are realistically only going to want to sync between 1/250 to 1/1000 so you shouldnt run into problems with your shutter speed affecting the flash component of exposure.


Is that really what you wanted to say?

While exposure might not be affected at these higher speeds, flash sync most certainly will be, and you'll most likely get dark bands from the shadows of the shutter curtains as they open too late or close too early because you're operating outside the camera's stated sync speed.


No it's not really what I wanted to say! I don't even know what I was thinking when writing that... I think it was more along the lines of that YOU CAN ONLY sync between 1/250 to 1/1000 (will explain in a sec) without running into issues, so you don't need to worry about your shutter choice affecting the flash power. Yes, that is what I was thinking.

But... you are right.

Any camera with a mechanical shutter cannot sync faster than its stated sync speed. OK well, technically, they can... but your going to get a dark band of frame that has no flash within it (but it still gets ambient light). This may or may not be a issue, depending on the composition of your shot.

A camera with a mechanical/elec shutter (such as D70/D50/D40) is able to be pushed further than it's stated sync, through the use of non-ttl flashes.

From personal use I have found that the D70 is not good to sync much faster than 1/1000 - 1/1250 because:
1. blooming issues can occur due to the elec shutter.
2. you are starting to get so fast that the electronics within the remote triggers cannot keep up with the sync.

Nonetheless, what I was getting at is that your chosen shutter speed will have no effect on how much flash light is apparent in your photograph. If you are wanting to balance ambient and flash, it is very much a combination of using your shutter to control ambient, and flash power levels to control yoru flash.

PostPosted: Fri Aug 10, 2007 12:13 pm
by mattyjacobs
wow, thanks for the tips guys! so much reading, so much to learn!

on shutter speed sych stuff ... the st-e2 and the 430ex have a high-speed synch option, so I can shoot up to 1/4000 and not get banding. I played with an old old old flash a while back and got banding at high shutter speeds, but haven't run into that with the canon stuff yet.

I'm also realising the need for light stands, and stuff to hold reflectors and all that ... even using the wall to bounce and balance the flash off.

so much to learn!

PostPosted: Fri Aug 10, 2007 12:18 pm
by jamesw
mattyjacobs wrote:so much to learn!


:D thats the best part about it!

PostPosted: Fri Aug 10, 2007 12:23 pm
by mattyjacobs
Reschsmooth wrote:OT - I ordered some coffee from Hazel - hopefully it gets here tomorrow!


Which blend? Let me know how it goes!

PostPosted: Fri Aug 10, 2007 1:12 pm
by gstark
mattyjacobs wrote:on shutter speed sych stuff ... the st-e2 and the 430ex have a high-speed synch option, so I can shoot up to 1/4000 and not get banding.


That could be sleight of shutter. :)

There's two different ways to acheive this. As James mentioned, if your sensor has an electronic shutter built in (like the D70) then this will be a viable option, provided you know how to turn on the electronic shutter.

The other way that this is acheived is by pulsing your flash, as your shutter curtain traverses the image plane. This method only works with flash units that know how to do this with the specific camera in question; some do, many do not.

My guess is that this is what your system is doing, so as long as you're using a paired flash unit, you're fine.

I'm also realising the need for light stands, and stuff to hold reflectors and all that ... even using the wall to bounce and balance the flash off.


The Poon light kits may be about to become your friend (the kits cost about the same as light stands + brollies from most other places, which makes the cost of the heads effectively $0), but also look at getting something like some bungee balls.

PostPosted: Fri Aug 10, 2007 1:13 pm
by Reschsmooth
mattyjacobs wrote:
Reschsmooth wrote:OT - I ordered some coffee from Hazel - hopefully it gets here tomorrow!


Which blend? Let me know how it goes!



Holy Hildegard - it arrived today, ordered Tuesday night, so am giddy like a little girl, waiting to crack it open and extract a shot (have been having average coffee at home of late).

Going even further off topic, I do love these shots of shots on Hazel's blog

PostPosted: Sun Aug 12, 2007 3:51 pm
by mattyjacobs
Nice, Holy Hildegard was good when I tried it. That was ages ago though.

Her partner shoots the photos, but it's not with a dslr ... I don't think so anyway. She showed me her camera once, can't remember what it was though.