Opinions On First Test Shot Using External Flash

[David Mitchell]

Hi all,

I have just decided to try out my basic external flash and my D3100 with the 35mm f1.8G lens with my house mate as a test subject. Due to the lack of TTL metering on the flash I have set the camera to manual and have worked out where I want the exposure.

Here is the first test image processed in LR, ISO 100, 1/100s, 35mm f1.8@f1.8, flash was set to 1/128, handheld.

Flash was offset to the left - its a fixed head but was being shot through a white umbrella.

Any comments on this or how I should do things better? These is my first ever shoot with an external flash but I am quite happy with the results so far!

 

[Pete Askew]

What an interesting pose!

The lighting is quite atmospheric and not too strong. I might have tried to bounce a bit back into the shadows a bit though.

 

[Dan Cattermole]

Good effort David.

I agree with Pete with the shadows.
Could we see the original version?

 

[David Mitchell]

Thanks guys, the flash is not TTL so I had to guess the exposure, its just a test example and its shot wide open on a 35mm lens - I did use the LR lens corrector (for any distortions this lens has). I did also try out the same thing with the 18-55 kit lens, worked ok but due to the smaller aperture it wasn't as easy - need to tripod mount perhaps, although I did have the ISO fixed at ISO 100, could bump this up a bit.

I need to work out what I should be using - also what focal length I should go with, I shot at 55mm with the 18-55 lens and it seems to be pretty good so I might be tempted to get a 50mm f1.8 lens as well, I can't really afford the 85mm lens though I guess I could look at getting a zoom although I do have limited space - this was shot in my living room lol

The shot was taken with just 1 flash, no other light in the room, I guess this might have thrown my exposure slightly as there wasn't any ambient light to add to, it was all done with a single flash.

When the O flash arrives I will have a go with that, although my D3100 doesn't like non Nikon flashes so I might actually have to mount the O flash upside down on a stand and shoot through it with a remote on the camera!

I do like the idea of a constant light source though eg with a ring light as this would make exposures much easier to do!

 

[Dan Cattermole]

So, no original version then?

Using external flashes I'd certainly be tempted to use a lower aperture f7.1 / f/8 and to maximise your flash output/ISO slightly to compensate. That way you'd achieve the most out of your lens in terms of image quality. Albeit depending on what result your after from your image too.
A 1.8 doesn't necessarily have to be used at 1.8 just because it is a 1.8, and certainly when you have the ability to fill the subject with a flashlight and have amble amount of movement to bump the aperture down slightly.

That's not to say that it's not aloud, because I'm a sucker for it... Especially when there's nice amount of bokeh in the background I'd really like to make stand out... But it'd have to be used in the right circumstances.

Slick Character by DanCatt, on Flickr

But when you have a white backdrop/wall in the background, you'll be safe to knock a few stops down easily and get more from your image.

I wouldn't be too concerned about lens distortion to be honest, that's the least of my worries about this lens. Barrel distortion is only around 1.7% which is hardly noticeable and something I never adjust. If I were you, I would concentrate more on the fundamental workings of a flashgun first before you over complicate things adjusting barrel distortion.

Good luck, any chance of that original?

 

[David Mitchell]

Lightroom can automatically correct for it anyway as it knows what lens you shot on so you just enable the lens correction, quite clever really

Hmm I am getting some contradicting information, one the one hand it is suggested to get a fast lens and shoot wide open to get a shallow depth of field, whereas others are saying that it doesn't matter and to shoot at f8 or so.

I also need some help as to what lens I should go with, my 35mm seems good (52.5mm equivalent as its a crop sensor), I am tempted to get a 50mm f1.8g which would work out at a 75mm equivalent. I will have limited space wherever I am shooting. I am tempted to get something like the 18-105mm f3.5/5.6 lens as it would allow me to shoot slightly longer when needed although the aperture is much smaller. That's the issue I have, do I go with a fast prime or a slower zoom lens?

 

[Pete Askew]

I would go with the fast prime and learn to see with that lens. Use the aperture to get the effect you are after. Often when using flash you will need to either stop down or pop a ND filter on as you will have too much light. If you go a continuous light source you can then exploit the narrow depth of field more.

 

[David Mitchell]

I have quite a lot to learn as its all manual, I did use the minimum setting with those photos at 1/128, I guess I just need to test as I don't have a meter to tell me what shutter speed I need, I guess once I get what I want setup I can use the same sort of setting and just adjust the shutter speed slightly if I stop the lens down - or increase the flash power slightly. Just trying to get a base of what works really, hence the test shots.

It will be interesting when the O-Flash arrives, will see how that goes I will use the same settings and see what happens - the issue is my D3100 doesn't really match with the flash so I hope I can get it to fire the flash properly!

 

[Pete Askew]

With electronic flash, as long as the ambient light is not too strong, the shutter speed is irrelevant as long as you do not set it faster than the maximum sync speed as the flash duration is very short. So you control the exposure by how much light the flash emits, distance, direction, filters / diffusers and aperture setting.

 

[Pete Askew]

http://www.cambridgeincolour.com/tutorials/camera-flash-2.htm

 

[David Mitchell]

Thanks for that Pete, I think what I might try next is to set up the flash how I want with the shoot through umbrella, then using the exposure compensation on the camera so that I can keep it in aperture priority mode but still allow me to shot easily at different apertures - eg if I know that the flash gives an extra 2 stops of light it will always give 2 stops of light if on the same setting.

 

[Pete Askew]

Aperture priority will force the camera to select a slow shutter speed based on the ambient light. It won't know about the flash and you will likely end up over-exposing the shot. Read up on guide numbers, set the camera to 1/100s and then adjust distance, power output and aperture to give a correct exposure.

http://en.wikipedia.org/wiki/Guide_number

 

[David Mitchell]

*scribbles notes* Thanks Pete, I am so glad that there is so much knowledge on this forum, I believe that my flash is a GN of 58, I plan to set the camera to ISO 100 as I want to keep any images as clean as possible from digital noise.

I think this is what I need to look at:

 

[David Mitchell]

Just taken 2 'selfies' with my simple setup - quite hard as I had to set the focus and then guess where to stand lol - was ok with the first one as it was shot at f8, the other one was shot at f1.8 so slightly harder!

Both shot at ISO 100, looks like I am shooting around 1-2 stops under but easily recoverable owing to the lower ISO, tripod mounted so I could shoot a slower shutter speed.

35mm f1.8g @ f8 1/25s shutter speed - 1/32 flash @ 2m



35mm f1.8g @ f1.8 1/125s shutter speed - 1/128 flash @ 1m

 

[Pete Askew]

I would wind up the power on that flash if you are shooting through an umbrella. Shutter speed won't help. You need to control the exposure using the aperture and I would try to keep around f/8.

 

[David Mitchell]

I would wind up the power on that flash if you are shooting through an umbrella. Shutter speed won't help. You need to control the exposure using the aperture and I would try to keep around f/8.

Thanks Pete, I will set it to ISO 100, 1/100 shutter speed and bring up the power on the flash, I will perhaps try half power next - the images actually look fine on the camera screen but are darker when loaded onto the PC - I guess that my exposure would be almost right if I weren't shooting through an umbrella!

I do like this lens, however I can see its a bit too wide for portraits so will have a look around for what I might want. Plan is to get cheaper M42 lenses and bolt it onto the NEX to see, I know a 135mm on a crop sensor is a bit too long, looking like something around 70-100 should be about right for the space I have. I am having to crop quite a lot of the frame at the moment, however the quality is still pretty good.

 

[Dan Cattermole]

Crank up the flash and/or the ISO on the first shot and you'll be flying shaggy!

 

[David Mitchell]

Just set everything up again, this is using my 18-55 lens @ 55mm @ f8, ISO 100, 1/100s shutter speed, flash was cranked up to 1/2 power, I had to drop the exposure by -1 in LR so its slightly over exposed but its a good start for the settings I would want to go with. I am going to keep the ISO the same, I want to keep it set to ISO 100 to keep any noise down.



I thought I would use the 18-55mm kit lens to see how that performs, it shows that getting something like a 50mm f1.8g lens might be good, although I could look at maybe a slightly better zoom lens that could do between 35mm and something like 70ish as at 55mm it seems pretty good for a head and shoulders shot with very little cropping needed.

 

[Pete Askew]

That looks much better. Good pose too.

 

[David Mitchell]

That looks much better. Good pose too.

Thanks Pete, I am quite impressed as the kit lens when its stopped down, I can see that the wide open 35mm lens is good for certain things, however for a shoot like that its nice to stop the lens down especially if there isn't anything distracting in the background. Image looks good, shame about the subject!

This is actually a selfie so I had to set the timer on the camera and get into place lol my flash stand has a fixed head so its just at 90 degrees hence the same sort of shot each time at the moment, will get myself an adjustment head and go for some other setups using a single flash. I am looking forward to when the O-flash arrives soon so I can try that out - quite impressed with the sort of look you can get with very little setup actually.

My setup consists of:

1 off camera flash
1 shoot through umbrella
1 set of cheap flash sender/receivers
1 basic flash stand
1 camera tripod
1 D3100
1 lens

I have just seen the Nikon Nikkor 55-300mm f4.5-5.6G lens, looks like I can get a cheaper 55-200 lens as well but its not a G. Maybe I could look at getting that lens as it would give me an 18-55, a prime 35 and a 55-300 tele.