Sunday, 22 February 2015

Green Developer?

 ID11 used with Fomapan
In the normal run of things the colour of your developer as you pour it out at the end of the developing period is nothing out of the ordinary. You just get on with the next stage of the process. That is until it comes out emerald green!. What was just another film processing session has just thrown up a number of questions of doubt, or has it? This is possibly the first time for quite a while that you have taken any notice of what colour the used developer was supposed to be. So what changed? Your film make?

Basically what you are seeing, if you have not used a pre-soak, is the anti-curl and/or the antihalation coatings, washing off in the developer. It has no affect on the developing process which is the first thought most of us have when presented with something out of the ordinary. Different developers can present varying colours depending on which film manufacturer you use.
RO9 used with Fomapan

Why add these dyes?

The halation dye is added to the back of the film base to stop reflections coming off the backing (Acetate or Polyester) into the emulsion, causing exposure affects, usually visible to the eye as halos around areas of brightness. Sometimes the halation coating is sandwiched between the film base and the emulsion or added to the film base itself giving it a slight tone. This in no way alters the way the film acts with the printing process.

So which film developer combination gives you this wonderful Green?

Fomapan is responsible for the green tinting of the used developer. The developers I have used - ID11 and RO9 have produced this colour, so suspect that this film may affect other developers. Although Foma produces the most striking colour, other makes also add a tint to varying degrees to the developer during the process.

Tuesday, 17 February 2015

New header picture.

As you can see we have refreshed the header picture and title with some fancy Text. I have been wanting to change this picture for some time but could not make up my mind as to which picture to choose. Until recently. Funnily enough It's been on display in the lounge for months. Even as a test strip I find it engaging. I have had a number of test prints over the years that I feel have worked better as an incremental image than the final result, so I thought why not! it is in keeping with the ethos of the blog.

The picture is of our 'trolley' sticking his head out of the rear window of the car. He is exceptionally pleased with himself as he has spent the afternoon up to his ears in water and soft gluttonous mud. So much so that instead of being tricolour his fur is slicked down with brown mud so badly he looks like he has used styling gel. Fortunately for us the back seat is covered with several blankets for times like this.

For a dog that loves to play in the water all day I find it strange that as soon as a bath is mentioned he go's and locks himself in his cage and then plays up no end when he is in the bath.

The picture was made using a Bronica SQAi producing a 6x6 negative on FP4+ developed in ID11. It is printed on Kentmere Paper 9.5 x 12 developed in Ilford multigrade. It happens to be one of the first batch of photographs I produced with this new paper. 

Saturday, 7 February 2015

Increasing depth of field (DOF)

Hyperfocal distance is not something that trips off the tongue in this modern age of auto focus. In fact digital camera lenses do not have the facility to take advantage of this compositional tool. You just have to compare today’s lens with yesterdays they don't have aperture settings and therefore you can not play with hyperfocal distance settings.

So what is Hyperfocal distance?

When a lens is set to infinity, the depth of field (D.O.F) closest to the camera is known as the Hyperfocal distance for that aperture. If you have an older lens its barrel will be marked with these distances.

How to change the Hyperfocal distance.

Set the lens focus to infinity, and then read the lower mark for whatever aperture you have set. If you then refocus the lens to the lower mark known as the optimum distance you will increase your depth of field by fifty per cent of the optimum.

For example:

This was made using a
 telephoto lens at close distance.
 The use of hyperfocal distance has
 pulled the area of sharp focus
to the front of the ball.
I have used an old 50mm Nikon lens (pictured) to show how it works. I have set the focus to infinity and the aperture to F16. The good thing about this lens is that it shows the upper and lower limits of each aperture with lines on the lens barrel. Looking to the right (marked A) you can see that the last line on the lens barrel is opposite the five meter mark (about fifteen feet). By resetting the focus to optimum in this case five (A). Then look at the lower limit (marked B) for F16, it is about two and a half meters (eight and half feet). The resetting will extend the overall sharpness of the picture by an extra two and a half meters which is 50 percent of the optimum.

The longer the lens the greater the increase is. For argument, an 80 mm lens with an aperture of F22 set, would have a depth of field from 2.8 meters all the way to infinity when optimum focus is used. Instead of 5.6 meters to infinity.

If  hyperfocal distance had been
used with this picture the
 front post would be sharp.
In some cases where you do not have aperture lines on the barrel of the lens some cameras and lenses have a shut down button. This allows you to see before you press the shutter where the hyperfocal distance ends. So you can adjust it if needs be.

Being able to increase the depth of field (D.O.F) can be very useful when using medium and long telephoto lenses for subjects close to the lens, allowing narrow fields of sharpness to be moved. This makes sure the front of the item is in focus.