Flash - Behind the scenes

[pxl8]

Stephen, to help with the DoF you might consider focus stacking several shots taken at different focus points. Your subject matter is ideal for this. Do a search for CombineZ, it's a free app that will merge the images for you and does a great job.

[wolfie]

It's an excellent piece of software, produces stunning results.
Full name is combine z5

http://www.hadleyweb.pwp.blueyonder..../combinez5.htm

Harry

[Don Hoey]

A busy weekend entertaining and its all been hapening here !!

Stephen, having read the posts and looked at the pictures the key difference is that in the second shoot you have increased the apparent size of the light source. When Harry mentions light tents and light scattered in all directions, the effect is to make the light source bigger than the subject.

Using the wall to bounce the light back has the same effect of enlarging the light from your flash. I have just done a quick graphic so others may understand this.

You have also managed in the second shoot to even out the reflections on the top wing and eliminate bright reflections that were apparent in shoot 1 pic. ( I believe these are called specular highlights ). So a very good effort.

Reading your plans for a light tent I have to agree with Harry in choice of material. PVC will I think create specular highlights as well as appearing a bit hard as a result.

Thanks for sharing with a behind the scenes as we can all learn something from them.

Harry, another superb picture. Setting us all a challenge !!!

Don

[Don Hoey]

I thought I would tackle a subject that would be a nightmare of reflections. This sort of subject would normally be considered ripe for a light tent to be used. Allways up for a challenge I thought I would photograph it on a bench, and would try adding the reflections.

This would have been easier in a light tent with the black reflections comming from small cut outs of craft card supported on wire stems. The same principle was used here to show it can be done without a light tent.

The reason for adding reflections to the sail is that it gives it some form. It is bowed and not flat.

In the set up pictures all the white surfaces are being used to provide the light reflections on the sail and not as light reflectors.
Although a flash is fired through the large Lastolite reflector, this is to project a diffused shadow of the tripod on the front part of the sail. Bolder blacks appearing from the mid point towards the back of the sail are reflections from black objects, flash stand,tripod legs and black card.

The first image is a straight shot to show the scale of the problem.
The two behind the scenes images show the relative positions.
The Reflection diagram shows where each reflection came from.

Altogether an interesting exercise. Next I will have to follow Harrys tip for making a light tent.

Don

[Canis Vulpes]

Originally Posted by Don Hoey

Allways up for a challenge I thought I would photograph it on a bench, and would try adding the reflections.

Interesting, all the time I thought reflections were bad but adding or controlling reflection is just another dimension to flash photography.

I shall have to revisit some of my shiny still life pieces with a view of enhancing refections.

Thought provoking stuff!

[Don Hoey]

As there was a bit more natuaral light today I thought I would try this one. The camera is black and the leatherette quite shiny, and adding photo's as a background would present quite a lot of difficulties if flash alone was used. As I am trying to keep things within the scope of anyone with 2 flash guns a bit of natural light was needed.

A light reading was taken and the flash set up to balance that. The SB80-DX was side on to just light the lens recess on 1/4 power. The Metz on the floor was used to bounce light off the reflector and give light to the top of the camera. The idea was to also slightly overexpose the background prints to avoid them taking over the image. The subject was the camera after all. The instruction book in colour also helps to focus attention.

The background images were from my first darkroom.

As can be seen the set up is not a complicated one. I had to brighten up the behind the scenes image as it was not as bright as it appears. Camera settings : ISO200 1/8 sec at f16.

Don

[Don Hoey]

With a bit of sun about I decided to take a picture of the Nikon F3. The background was to ring the changes from others I have used. The 1.4 lens that I have used on other pictures was used, as it has a large set of elements, and I could get a decent reflection to counteract the black of the camera.

The key light for this was daylight and the flash units were used to add a reflection on the lens and the front left side of the camera. To make the flash light source appear as large as possible 2 flashguns were fired through a Lastolite reflector.

Exposure was manual so a light reading was taken in manual mode 1/8 sec at f16. The flashguns were turned to 1/4 power and moved relative to the subject to get the light balance right.

If you look at the picture you will see mention of ' black flags '. To bounce light back into the subject I placed 2 reflectors to the left and overhead. To limit the reflections pieces of black card were used to mask the reflectors. As the camera bag is quite a light colour it would have been slightly overexposed without this. If you look at the F3 @ 2 PM picture you can see how the side of the bag disappears into shadow.

Two pictures are here to show the change in colour temperature of the light. White balance was left on auto for both pictures. The first picture F3 @ 2 PM was taken at 2 PM. I decided to leave the set up and returned just before 3 PM when I took the second picture F3 @ 3PM. Removing the lens cap to get rid of a long shadow, and slight repositioning to get the light filling in the base of the motor drive.

Don

[Don Hoey]

Inspired by Jon Sharp's thread ' Mini Challenge - "In my garden". '

Not much happening out there at all but I did manage to find a few Winter Aconites poking their heads through the leave litter. Most were inaccessible but I found one that was. The light today was very poor, totally overcast skies. An incident light meter reading suggesting 1/8 sec @ f16 for ISO200.

I have attatched a picture of the subject in an as found condition and is a straight exposure. With such dull conditions a touch of flash was going to be required to lift the scene. A small amount of gardening was done as is indicated in the final picture. Three lighter coloured leaves were introduced. The foreground leaf was turned 180 degrees, and the other darker leaf just lifted a tad.

The lens used was an AIS Nikkor 55 Micro so focussing was manual as was exposure. Flash was used to add a bit of colour to the leaves. The effect can be seen in those leaves I did not affect with my bit of gardening. This required the flash to have maximum diffusion so that its effect would be subtle. Flash exposure was judged by using the variable output control and ended up at full power where I had initially placed it. The time of the final exposure was moved from 1/8 sec to 1/6 sec to give a plus 1/3rd of a stop over the initial image.

Don.

[Canis Vulpes]

Superb photography as ever Don,

I dont understand how flash has warmed the colour of the final image. Flash light has a cold 4000K (ish) colour temperature so why have the warm colours come out so well?

[Don Hoey]

I did not quite expect this as a lot of members including yourself shoot RAW and correct the effects in RAW so failed to explain properly.

I am trying to think in film technology terms. If I move up to D200 or D2X I don't want to add a new PC to the bill immediately, ( currently on 128mb RAM ). So I am now doing everything in JPEG as practice - back to the roots !!

Colour temperature works in reverse of what you may expect - low numbers = warm, and high numbers = cool. Daylight film is balanced for 5500k. So a scene that has a higher colour temperature ( eg overcast daylight ) will be cold, and that with a lower colour temperature ( eg domestic light bulb ) will be warmer.

I think digital sensors must be calibrated around 5500k - 6000k, as my results with electronic flash which is around 5000k do give a slight warming. A similar warming effect could have been achieved with an 81A filter. In this case it was very overcast so flash was really needed.

When I did the Nikkormat I had been doing quite a bit of RAW and failed to notice that I had an 81A filter on the 105mm lens. Realised this soon after posting my behind the scenes. Did not go back and comment for fear of confusing things, but now the subject has come up ......

I will look on the net and see if there is something worth posting a link to.

I will attatch the two images here appropriately titled. Quite a difference.

Don