A little while back I reported that I was struggling to get my Infrared images from my GX1 to meet my expectations. I was experiencing difficulties with depth of field, focus and my images seemed grainy and soft. And whilst I did achieve some improvements to the quality I wasn’t entirely satisfied the results. The real problem however is that I have nothing to compare my results against so it might be that all Infrared images are soft and grainy. Well, I have had something of a revelation over the weekend and have achieved some very high quality images with which I am delighted.
The source of my problem was identified after a friend sent his Nikon camera for conversion. When returned the lens had the UV filter removed and this had been carefully packaged with a note saying “DON’T USE WITH INFRARED”. When he spoke to the company they said they had encountered a number of problems in the past when these filters are used on converted cameras. Whilst all filters are not the same, there is no way of telling which cause a problem so he was recommended to buy a clear glass lens protector instead.
As soon as I heard this I searched the internet but couldn’t find anything about this problem. I decided to do some quick tests by simply removing my UV filters (expensive B&W ones) and the results were amazing. The areas that had been very soft were now much sharper. The graininess that had been apparent in images had now cleared. The images were now significantly sharper with fine details appearing crisp. And the distortion appearing towards the edge of the frame (especially in the corners) was reduced significantly, down to levels expected with these lenses.
Now you might recall that I mentioned my 45-200 lens didn’t display such strong problems as my 9-18 lens and that my 18-45 lens was worse than the others. Well checking the filters, the one attached to the 45-200 was a cheap 7 Day Shop UV filter which appears to have much less effect than the B&W filters. When I checked the B&W filters I found one of them caused more problems than the other.
I am now on the lookout for clear glass 52mm filters that do no filtering at all. Until I find them I will be shooting with the front lens element exposed.