Flash - Behind the scenes

[Don Hoey]

Lello,

I will now settle back and wait for your next picture. You have now set yourself a standard.

Don

[robski]

I see you have a second apprentice Don

[Canis Vulpes]

Originally Posted by Don Hoey

How large are the subjects you are considering ?

I have two large graduated backgrounds that are washable silk finish plastic. They are years old so no idea of current cost. NFB may be able to advise.
Don

The graduated background are produced by Colorama, approx size 1.2 x 1.8m. I sourced one for £50 +VAT. They are white on the back and the white backdrop photos show the colorama in reverse. My black background is provided by a roll of black freise paper (£5ish) from office world, approx size 0.8m x 15m.

I have been in search of a piece of black velvet but to no avail, even employed mumsey in the search!

[Leif]

Thanks for the background suggestions. I will look into them, with the exception of employing 'mumsey'.

[Don Hoey]

Originally Posted by Stephen Fox

I have been in search of a piece of black velvet but to no avail.

Stephen,

May I suggest the dress material department of a large Deptment Store eg John Lewis, or a haberdashers.

Don

[Stephen]

Originally Posted by Don Hoey

Stephen,

May I suggest the dress material department of a large Deptment Store eg John Lewis, or a haberdashers.

Don

I would agree, though I seem to remember getting mine from the local market. It doesn't have to be the best quality, just a full width piece and long enough to use as a portrait backdrop. If thats to be a potential use that is. This stuff really does absorb all the light you would normally throw at your subject

[Don Hoey]

Originally Posted by Stephen

I would agree, though I seem to remember getting mine from the local market. It doesn't have to be the best quality, just a full width piece and long enough to use as a portrait backdrop. If thats to be a potential use that is. This stuff really does absorb all the light you would normally throw at your subject

Stephen,

I never thought of the market ....

Don

[Don Hoey]

Following comments in the Gallery I thought I would post a behind the scenes.

This picture was taken to see how the new camera handled flash lighting.

Sounds an odd statement but the tests so far have shown up new considerations to be taken into account.

Something I had not paid much attention to before studying for my upgrade path was ' diffraction limits ', and ' airy disks '. My tests yesterday showed that with a combination of my ' less than top grade glass ' and the effect of diffraction, f13 would be the minimum aperture that I can set on my 28-105mm lens. Beyond that and images really start to loose bite. ( D2X diffraction limit is f8 ). I have yet to try my old Macro 55mm out to see if it fares any better beyond f13.

As these were tests, the camera was chosen as a subject as it has sharp detail and could be positioned for a realisitc challenge for control of dof within the limits of an aperture of f13. The image has a slight crop of the bottom and a bit off the top and was taken at a focal length of 85mm at a distance of 1 metre.

Shed loads of resolution does have downsides other than the diffraction limit. 100% crop shows the prism is not as pretty a sight as one would like. Thorough cleaning before a shoot is now more essential than ever as shown by the area around the shutter collar.

Attatched is a behind the scenes shot and a graphic to explain the setup, the final picture and the 100% crop.

Don

[Canis Vulpes]

In the toy shop this morning with James I saw something 'I' liked and thought would be good to photograph.

A small toy helicopter I indented to show rotor blur. Using flash of course to give a zip of life.

During initial setup I noticed I could not really get the rotors blurred so it seemed on the LCD screen. I had to use LCD screen of camera now my personal laptop failed.

No.1 below shows initial setup with undiffused flash (I expected to remove shadows using diffusion at a later stage) experimentation at this stage was with rotor blur and shutter speed. I went down and down in speed still stuck rotor!! - Then I thought about it! Flash occurs over a tiny period of time freezing the rotor and the remaining exposure time would record the blur but nowhere as strong as the initial burst of flash light.

I had to use a no-flash setup to obtain the desired picture. Exposure over approx 1/5 I caught it. (No.2)

Using diffused flash decided to capture MY new toy without moving rotors (No.3)

I'll post No.2 in my gallery.

All good fun .

[sassan]

# 2 undoubtedly gets my vote. The only question now is how to increase the opacity of moving rotors.