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| Flaming Tree, New Forest, Hampshire - X-E1 IR / XF 14mm |
The modification involved the removal of the IR blocking filter in front of the sensor and its replacement with an 830nm Schott glass IR pass filter.
ACS offer filters of several strengths ranging from 600nm to 830nm depending on the IR effect you wish to achieve. The lower the cut-off wavelength, the more visible light is allowed through as well as infrared light, permitting "false colour" infrared techniques to be explored.
Because the X-E1 is mirrorless camera which uses the contrast detection on the sensor to auto focus, no AF adjustment is needed to accommodate the difference in the focus plane of IR vs visible light - a real problem with modified D-SLR cameras.
It also has the huge advantage of allowing live viewing of the infrared image through both the viewfinder and on the rear screen.
Since ACS performed my "pioneering" modification they have converted many more X Series cameras for customers all around the world.
In August 2015 Fujifilm US announced a special full spectrum version of the X-T1 called the X-T1 UVIR. This isn't strictly an infrared camera as, although it sees light in the infrared spectrum, it also sees the full visible light spectrum and part of the ultraviolet spectrum with a range of 380-1000nm. It is aimed at technical experts, law enforcement, medical research and scientific communities. To use this camera for IR photography you would need to add an external IR pass filter to the end of the lens.
However it does demonstrate Fujifilm's confidence in their X-Trans sensor's ability to resolve infrared light and produce stunning IR images.
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| Portland Bill Lighthouse, Dorset - X-E1 IR / XF 14mm |
I already have an XE1 converted to 850nm but I am considering having another converted to full spectrum hoping to utilise a full set of Kolari IR filters plus a B+W 403 which gives false colour on such a conversion without swapping the colour channels. The fiters are 52mm so hopefully I would get decent results from the 35 f2 using a step up or the 35 mm 1.4, I also have the 18-135 and a 67mm Hoya 720nm filter. I also could use my 14mm with the 67mm 720nm via a step up ring.
ReplyDeleteDo you have any experience of or knowledge of how well a full spectrum conversion would work with those lenses.
Mal.
Hi Mal
ReplyDeleteAll the testing I have done has been with IR only converted cameras but there are a few general principals that we can draw on to asses full spectrum performance:
[1] Hot spots are far more prevalent at IR wavelengths than at UV so it is likely that any lens that performs well in IR will also perform well with a full spectrum conversion.
[2] Specialist IR multi-coating will be a big help with all the filters and I know Kolari offer this on some of their filters.
[3] The broader the range of wavelengths you are trying to focus in a single plane, the less sharp the final image - this is why I always advise an 830 or 850nm conversion for those who only want to shoot B&W IR as it produces much sharper results than a 720nm or lower filter
I would suggest contacting one of the conversion companies such as ACS or Kolari and seeing what their experience shows before taking the plunge - my instinct is that a full spectrum conversion may be the jack of all trades but the master of none...
Happy shooting - Simon
Many thanks for your advice Simon, it certainly is food for thought as the full conversion XE1 850nm is certainly sharp using the 14mm.
ReplyDeleteI will drop ACS a line and see what they recommend.
Mal.
Hiya. I'm loving the look of your Fuji 830nm IR shots, but I'm worried about the amount of PP that may go into these photo's if I get my XT10 converted. Do you have to do the full custom WB and colour swapping that I've seen?
ReplyDeleteHi Alan
ReplyDeleteWith any conversion you will need to set a custom white balance but this is a once only process that once set stays in place for that camera regardless of lighting.
The way I suggest you do it is to fill the viewfinder with brightly sunlight fresh grass - slightly out of focus - and use that instead of a grey card to set the custom WB - save and job done!
Beyond that the post-production is minimal - that is the beauty of having a B&W only 830nm conversion. The image is B&W in camera, no channel swapping is required, just a touch of levels and curves and season to taste in NIK SilverEffex Pro 2.
Cheers - Simon