Following our return from Ireland the task of moth identifications began in earnest alongside the continuation of trapping at home.
This of course meant changing back to my macro lens which I had left at home during our trip abroad to keep it safe.
It was immediately apparent that during the process of changing lenses either before or after our trip some dirt had managed to get into the camera and onto the sensor.
After my knee jerk on the first occurrence of this problem I decided to try a more controlled approach this time.
After reading the camera’s user manual and researching on line it appeared that with care I should be able to resolve the issue myself without having to resort to sending my camera off again to a specialist.
My reasoning did have an element of the financial cost but also from what I had read the indication was that this problem was likely to occur regularly, and I may well be in a location where an expert may not be readily to hand.
There are various products on the market for cleaning a camera’s sensor such as swabs and cleaning fluids but, as I always tend to air on the side of caution, decided to try the air blower approach where I would not have to make any physical contact with the sensor itself.
The first part of the procedure is to locate the little offender which is quite straight forward as my camera has a menu option called dirt alert which gives a graphic display of the sensor and smut location.
As explained in the previous post on focus stacking one tiny speck in the wrong place can become a nightmare.
The next step is to remove the lens from the camera and use a menu option called sensor cleaning which effectively lifts the camera’s mirror to give access to the sensor itself.
Once the mirror is lifted the idea is to raise the camera facing downwards so the any dirt dislodged during the process would hopefully fall out.
Aiming as carefully as possible at the highlighted area in question giving two or three quick squeezes which should be sufficient.
On completion of this operation switch off the camera so that the mirror returns to its normal position and put back the lens to recheck using the dirt alert function as before.
If this does not resolve the problem, as happened the first time I tried, as the little offender, although moved, was still visible, the process needs to be repeated but this time hopefully with more confidence.
In my case this second attempt was successful, as I had managed to dislodge the foreign body leaving my sensor spotless once again.
I have now carried out this operation on many occasions problem free and to date, have not had to resort to fluids and swabs.
Thought and consideration is needed when changing lenses to prevent any dirt getting to the sensor in the first place.
For example, changing lenses on a beach during a gale force wind should obviously be avoided if possible.
I eventually came up with the idea of purchasing a 1.4x AF Rear converter with a view not only to getting a tighter crop on my images of the moths but hopefully with the added advantage that if left in place when changing lens would also prevent the influx of any dirt.
This leads nicely to teleconverters and magnifying lenses which will be the subject of my next Sunday post.