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.

Cropping your photograhs

Print of the whole negative

When it come to cropping your prints there are two schools of thought. Those that believe that once the view has been carefully framed in the camera, you should print the whole negative and in some cases include the rebate as well to prove it. The alternative view is that each image is unique and should be judged as such irrespective of its format.

My stance tends to follow the latter view or what best emphasis the composition whole frame or part of. It does not always follow that what your pre visualized view at the time translates to the baseboard when it comes to printing. 

It is important to consider how you're going to frame the image at the beginning of the printing process. The start of which is the contact print once produced time should be taken to consider what is best for each picture. In some cases it is an automatic decision how the picture is going to look. In others it is not quite so clear as to what is right. In these situations it maybe better to print the whole negative and use a crop tool to ensure what framing brings the best out of the image. 

Cropped for impact

Setting hard and fast rules when it comes to producing your pictures will prove detrimental in conveying the vision. It is better to keep an open mind and be bold in the way you frame your pictures. Sometimes it is good to seek other peoples opinions they may offer an idea that you have not considered, but remember these are suggestions that should not be followed blindly. You should only do what others indicate if you truly believe that it is the best for the composition and coincides with your vision for the picture.

I crop photo's for a number of reasons some listed below:

• 

  change story

  To remove unwanted items from the picture that sometimes get missed in the making process from around the edges.
• To correct a bad holding angel.
• To remove processing faults, dust hair etc.
• To change the balance and or emphasis of elements in the picture.
• To change the format of the picture.
• To remove dead areas from pictures tightening the composition.
• To create a better sense of intimacy.
• To improve composition.
• To tell a different story. If you are doing this then you should give serious consideration to the facts of the situation before changing the emphasis especially from a photojournalists perspective.

Crop tool.

You can use a crop tool which was mentioned earlier. It can help to improve how you compose images at the making stage. It is a way of training your eye.

Crop tool made from

They are simple to make as described below:

You can make a crop tool out of two bits of cardboard it needs to be 50 to 75mm (2” to 3”) wide and 500 x 400mm (20” x 16”) long or bigger than the largest print you are likely to make. If you do not want to make it completely from scratch then you can use a pre cut mount frame cut to make two L shapes. This allows the framing of the picture to be infinite.

This simple idea allows you to try out those more radical ideas along with the more prosaic to see if they work. It may surprise you in the process.

Scanning Photographs

Before adjustments in  Photoshop

Using a scanner for photographs is slowly becoming a thing of the past. I say a thing of the past but what I really mean is that you no longer need to use a flat bed scanner to reproduce your photographs to share with people digitally. You can if you wish use your smart phone or digital camera to reproduce the pictures you make.

As some of you know, most of the black and white images I share with you on this blog are scanned from photographs. Over the years I have developed a simple method for getting the best from my scanned prints and negatives. I like to keep things straightforward when it comes to digitizing prints. There is no point in doing a lot of work in Photoshop when I have already done it in the darkroom.

Levels adjustment.

Hus and saturation adjustment.

I use a very old flat bed Epsom scanner. I open the software on the computer and a window comes up with a number of pre-sets on it. In most cases I scan at original size, that's because my photographs are A4 and larger. This is done at three hundred DPI. I usually end up with a file size of about twenty four megabytes and under four thousand pixels on the longest side which is more than enough for screen display. The unsharp mask is set to medium. I always scan in colour even for monochrome and save the files as tiffs. Dust removal is set to zero, I have found it better to use a very slightly damp cloth wiped over the scanning window a few minutes before use to remove any bits. Far better than letting the software do it.

After all the adjustments have been added

Once on the computer I open the file in Photoshop. I check the picture at one to one for blind pixels, specks, process faults and dust etc, that have transferred from the darkroom process. The scanner tends to flatten the contrast of my images so I adjust the contrast to replicate that of the photograph in a levels mask. Once done I open hue and saturation mask to adjust the tone of the picture. If you use toned papers and developers the scanner under represent these as well hence the adjustment. Once done I flatten the layers and re-size it for web use.

I know what you are thinking that's a lot of work just to share a picture. If you think it is a good picture it's worth the work. It is a lot less work than some digital photographers do, who can use some forty or fifty layers to get the picture right.

Taken with a camera

I have included a picture from my phone and digital camera for comparison. Both pictures have been checked in Photoshop. Adjustments? Levels a slight tweak but no where near as much as the scanned photograph. The thing to watch for are reflections especially with gloss paper. If you look carefully you will notice some but not enough to detract from the picture.

A phone or a digital camera is a good way round not having a scanner for sharing images of photographs. These methods will not completely replace the consistent quality of a good scanner but will allow you to share you analogue work if you are on a tight budget.

taken with a smart phone.

 

Images for sale.