UV (Ultraviolet)

All the exclusivity/rarity arguments in Why Multi Spectrum Photography Is So Rare apply with gusto to UV photography.  Shooting UV requires:

1. modified camera -- no way to wing it, unlike IR
2. either resigning to absolutely abysmal image quality or buying exotic lenses, costing $6K+ each, manual-focus only, and pretty much limited to 60mm-105mm range (in other words -- forget about wide and telephoto):
   a. Coastal Optics UV-VIS-IR 60mm Apo Macro
   b. Pentax 85mm F/4.5 Ultra Achromatic Takumar Asahi (only available used)
   c. Nikon 105mm F4.5 UV Lens (it's sold brand new from Company 7 for less money than it sells used on Ebay.)
   d. Coastal Optics UV-VIS 105mm CoastalOpt® SLR Lens (reviews indicate Nikkor is superior, especially in IR)
   e. Some exotic Zeiss medium format lens, selling for $25K+ on Ebay these days
   The only good news with these lenses is that you are likely to pay more for them when you sell them, after finally giving up on UV photography.
3. $400 Baader UV filter.  Cheaper filters will allow VIS and/or IR to leak in, or, alternatively, rob you of the already-very-limited UV flux (read -- steal a stop or two).
4. To Be Continued...

Why Multi Spectrum Photography Is So Rare

Very few people shoot infrared, many fewer yet shoot full spectrum, and practically nobody shoots UV.  There are many reasons for this, I believe.

Equipment

Cameras

1. While technically possible, shooting Full Spectrum or Infrared without dedicated, converted (by replacing hot-mirror) camera is super-painful.  Using cameras without conversion, exposures are extremely long, mandating tripod and excluding scenes with any movement, and good results are much harder to obtain.
2. For good results, the camera must have a very high dynamic range, very low noise, and great shadows recovery.  Much more so than for visible-only photography.

Together, (1) and (2) mean that one has to take a very expensive camera and pay several hundred dollars... to very significantly damage its resale value, to say nothing of automatically cancelling the warranty.  While it is certainly much cheaper to buy an already-modified camera second hand, high-end modified ones become available very rarely.  Thus, most people experimenting with IR choose to use highly sub-par cameras.

Lenses

Most lenses tend to have one or more issues of variable severity with IR, and absolute majority of lenses have terminal issues with UV.  There are no cheap lenses that perform well in UV.  There are some non-exotic lenses that do well in IR.  A lot fewer of them do well in Full Spectrum.  Finding these, both due to their rarity and the lack of reliable information on the web, is hard.  Most people dabbling in IR thus choose to use whatever lenses they have (usually inexpensive zooms, which are, with few notable exceptions, the worst performers in IR).

Overall Equipment Choice Impact

Thus, most people experimenting with IR end up using very poorly suited (to this task) cameras AND lenses.  Sadly, the negatives don't cancel out, but, often, multiply.  The bad lenses will likely produce lots of blur (especially in the periphery), lots of chromatic aberrations (a lot of it not fixable in software), veiling flare, and hot spots.  The camera will add insult to injury by generating lots of noise (hopefully without the ugly banding structure, e.g. Canon), and may even focus badly, exacerbating the blur.  Thus, even with perfect pre-exposure technique, results out of the camera are likely to be very bad purely due to the equipment choices.  But wait...

Pre-Exposure Technique

Shooting full spectrum and infrared is quite different from shooting visible, because it's hard to say how things will look by just looking at the scene.  Full Spectrum and deep IR (800nm+) shots will look very bland (compared to likely ideal post-processed version), whereas super-blue (blue + IR), super-color (590nm), and traditional (725nm) filtered results will look nothing like the expected post-processed results, complicating out-in-the-field judgement.

It is very important to know the limitations of one's equipment, including optimal aperture range (and verboten aperture ranges) for every lens/spectrum combination, whether the lens is question can accurately auto-focus in a given spectrum, as well as maximum ISO at which the noise in the post-processed result is still acceptable.

Finally, cameras tend to get the exposure very wrong, and correcting for it is vital (due to expected drastic modifications coming in post).

If any of the above are gotten quite wrong, added to the damage already coming from the equipment, the results can easily be predestined for bit bucket before the image is ever loaded in Lightroom or Photoshop.

Post-Exposure Technique

Most IR exposures require relatively significant post-processing prowess to get them to look great.  I consider myself a relatively advanced Photoshop user, and yet I often struggle to produce acceptable (to me) results from exposures that I am pretty certain should be workable.  The only (partial) exception to this rule is deep IR (800nm+) exposures, which require one to be relatively good in B&W processing, but no more than that.

It is not easy to do a good job post processing even those exposures which are made using top of the line equipment and very good pre-exposure technique.  Adding sloppy post work on top of a badly planned and poorly executed exposure made using inferior equipment is, well, unlikely to please.

Summary

Shooting in FS, IR, and UV is similar to the traditional visible-light photography... in the beginning of the 20th century.  There is a long and complex pipeline of steps to get the final result, very few people have the knowledge and skills to do all these steps well, and screwing any step up seriously inevitably leads to failure.  Fields with this property tend to have few players.  Which is one of several reasons (see my previous post) why I chose it.

Why Beyond Visible?

I believe it is important, in any endeavor, to have a clear goal, or, at least, a justification for doing it.  I have been producing photo-based-2-D-images (see next post) for many years.  With the exponential explosion of the number of these produced in the world, I see the following choices for someone into this activity, assuming the goal is to produce results interesting to others:

1. One can dedicate themselves to being "at the right place at the right time", spending lots of time and money, and likely end up producing mediocre work (much above the bland mass, much below the very best).  I always found this approach very boring, and due to my work and family situation, this is not practical for me anyway.
2. One can study:
   a) pre-exposure techniques (composition, most notably, but also multi-spectral photography, multi-exposure (for HDR, stitching, noise reduction, or super resolution), ICM (Intentional Camera Movement), long exposure, etc.)
   b) post-exposure processing techniques (Lightroom, Photoshop, HDR, stitching, 3-rd party filters, simulated paintings, etc)
   and apply these to relatively every-day, mundane scenes.  With lots of work and creativity, I believe very interesting results can be achieved using this approach, and that's what I try to practice.
3. Shoot human or animal subjects which are both unique and will garner unique interest for a certain (likely very small, unless it's Kim Kardashian's butt) subset of the population.  I fancy myself a decent portrait photographer, and yet I realize that even my best portraiture work is unlikely to be of much interest to those who don't know the people involved.

Thus, to me, multi-spectral imaging is just one of many pre-exposure techniques one can employ to produce unusual work, and it has several notable advantages compared to visible light photography:

1. IR (infra-red) and even FS (full spectrum) require good amount of technique, both pre and post exposure, and dedication to choosing and purchasing appropriate equipment, all of which significantly reduce the number of people playing in this field.  When combined with other relatively uncommon techniques, such as HDR, creative filters, and creative post-processing, it is quite easy to produce results which are very rare, if not outright unique.
2. Unlike visible light, which is best in the morning and evenings, full spectrum, and, especially, infrared, are best at noon.  Well, not necessarily best -- because it is scene dependent -- but because warm colors of the low sun are not a factor, and sheer amount of flux (especially important for UV and deep IR) is far larger at noon.  This means one can shoot when one is normally out and about (during the day), and not necessarily exclusively at sunrise and/or sunset, which is quite limiting.
3. Full Spectrum (which, for practical purposes, is pretty much VIS + near IR -- more on this later), depending on the scene, may more than double the amount of available light, thus giving about a stop of extra exposure latitude.  This may not sound like much, but keep in mind that this is about the difference in noise between a full frame and APS-C camera.
4. With a Full Spectrum camera, one has an option to use a camera as VIS-only, Full Spectrum, or any type of IR -- by just putting a different filter on the lens.  With the help of a magnetic mounting system (I use Xume, this can be done relatively quickly and easily with no screwing needed.
5. This field is highly exploratory and experimental in nature, which is important (to me, at least) to keep the excitement level high.

I will have a separate post on the downsides of invisible spectrum photography.

Manifesto

My goal is to document what I learn experimenting with infrared, two spectrum (visible plus infrared), and UV photography.  I will talk about all aspects, including equipment, technique, and post processing.  I don't intend this blog to be a tutorial on the subject -- many kind souls have already done a great job providing introductory level material.  My goal is to document what I have learned and did not find to be readily available information on the web.