Experimenting with f-stops

When using a macro lens it is vital to have an understanding of f-stops.  If I left my camera on the automatic setting it would always pick f/2.8 or f/5.0 when I'm taking macro images.  The f-stop will determine the aperture.  The aperture determines how much light enters the sensor on the camera.  The smaller the f-stop number the larger the aperture so the more light hits the sensor.  Alternatively the larger the f-stop the less light will enter the camera.  With larger f-stops the shutter speed is slower so a tripod may be necessary, increased noise may also arise leaving images looking grainy.

For the following images of an asiatic lily, I had the camera on the AV setting.  I fixed the ISO to 200 and changed the f-stop.  The camera determined exposure automatically.

Here I used f/2.8, exposure 1/1000s, ISO 200

F/2.8 gives a minimal depth of field which results in the stigma being the only part which is in focus.

f/5.0, exposure 1/400s, ISO 200

Slightly more detail is starting to reveal.

f/13.0, exposure 1/50s, ISO 200

Now you can see the spots on the petals and more detail in the anthers.

f/25.0, exposure 1/13s, ISO 200

A larger depth of field is given showing the most detail.

Asiatic Lilies

Asiatic lilies give great impact and are really easy to grow.  They may not be fragrant like their oriental hybrid relatives but they come in more colours and flower earlier.  I grow mine in containers on the patio.  They are really simple to grow from bulbs and it works out a lot cheaper than buying them in bud from a garden centre.  They're simple to look after too, I just stake mine if they are getting to big to stand up straight by themselves.  Just watch out for lily beetles.  When I was watering my plants a few nights ago there were about eight of these little critters on my lilies.  They are red with black bodies, and make lots of holes in the foliage.  I have to admit the horticultural part of my brain kicked in before the photographer part, because they were all dead before I had chance to take a photo of them.  I prefer to be organic and knock them off the plant and stand on them rather than spraying them.  If you need to use chemicals to get rid of them, use one with contains thiacloprid or imidacloprid.

To view full picture:

http://www.flower-pictures.co.uk/p381546101/h3ff67e96#h3ff67e96