On to the sticky subject of lens cleaning.

After reading an article on lunar photography, I was taking some photographs of the moon. My instinct was to use a tripod, remote shutter release with a long exposure and a high ISO but that’s totally the wrong way around. The article reminded me that the moon was reflecting light from the sun and if you set things up correct then you can grab a good shot holding your camera in your hand.

So with camera in hand, wide aperture, fast shutter and a low ISO I grabbed this shot...

That glow around the moon was so annoying and I couldn’t work out where it was from.It was on all the shots but with a little bit of work in photoshop elements I could clean it up a little. The shot could still be better though. I had cleaned my lens with a microfiber cloth so what was going on. The only thing it could be is a dirty lens so I decided to do a little research on lens cleaning. It must be the way I am cleaning the glass, which is the problem.

It was a little bit frustrating as the information that I was reading on one page was contradicting what I was reading on another. One page was saying to use rubbing alcohol (70% Isopropyl alcohol) when another site says not to use it. Admittedly, the page saying not to use Isopropyl alcohol was promoting a lens cleaning product called Lenspen (www.lenspen.com), more about that later. After looking at a bottle of lens cleaning solution that came in a kit that I got from Jessops (www.jessops.com),I found it contains Isopropyl Alcohol so decided that that was the way to go.

So on to the best way of cleaning a lens.

First of all the kit you will need is as follows.

· Size 12 flat (brights) brush. http://tinyurl.com/35bbynb
· Two microfiber cloths. http://tinyurl.com/2vj3unl
· A rocket blower. http://tinyurl.com/2vz5ulm
· Isopropyl Alcohol 70%
· Powder free surgical quality gloves.
· Bright working light.

The bright working lamp helps you spot bits of dust and grime that will not normally show up. The gloves will be needed as the Isopropyl Alcohol is not good to get on your hands and you may have a reaction to it leaving you with sore hands. Powder free gloves because you do not want to cover your lens in powder as your trying to clean it.

The first job on the list is the lens cap. What would the point be of spending the next 30 minutes cleaning a lens only to put a lens cap back on that is contaminated in dust? So, get your rocket blower and blow all the loose dust out of the lens cap. Lightly tap it on the table to get the more stubborn dust particles out. Next, with your brush, clean out any dust that remains in the cap.

Next, its time to move onto the lens itself. Again, like the cap, blow off any loose dirt and dust with the rocket blower being careful not to touch the lens with the tip of the blower. Then with the brush, carefully brush off the remaining dust. If you don’t get the dust and grime off before you attack it with the cloth, you risk scratching the lens with any hard particles on the glass. Next, take one of your microfiber cloths and wet it with the Isopropyl Alcohol, do not soak it in the liquid, but make it nice and damp. Do not put the fluid directly on the lens. With a circular motion, from the centre outwards thoroughly clean the lens. Do not press hard on the glass. Light pressure is all that is required. Then, with the other clean microfiber cloth, again, from the centre working outwards clean up the alcohol. If you use Isopropyl Alcohol 70% this will give you plenty of working time to clean the lens. There is no reason why you can’t use pure Isopropyl Alcohol, all it will mean is that it will evaporate quicker giving you less working time. If you decide to water down the alcohol then you have to uses pure ionised distilled water, otherwise you risk introducing contaminates into the solution that can damage the glass. Best advice is to ether buy Isopropyl Alcohol 70% or work quicker.

It is exactly the same process for the rear glass but you need to take a lot more care as it is a lot more prone to damage than the front glass. As the rear lens is inside the camera body it is very unlikely to get dirty anyway so you may not need to bother cleaning this lens as often. With long focal length lenses it is possible that the rear lens will be deep inside the lens body and may be difficult to clean. If in any doubt I would recommend getting your lens cleaned professionally.

After I finished cleaning my lens, out I went with my camera and took another moon shot. The results are below.  

Camera Nikon D40
Exposure 0.002 sec (1/500)
Aperture f/5.6
Focal Length 200 mm
ISO Speed 400

Taken on September 25, 2010 at 9.34pm BST

Regarding the lenspen cleaning system. These pens are a exelent product but I find are best for quick cleaning while out in the field. They do an exelent job, the brush is of very high quality and good for brushing off dust.

Jessops are selling a kit containing a pack of four difrent pens for about £12. I would advise anyone who takes photography serious to get a set.