Originally posted by theutahbigfoothunter
I have heard that you need at least a 500 mm to get "good" quality pics of UFOs. I am wondering if 2600 mm is overkill? Should I be somewhere in
between?
I would say, it depends.. the majority of UFO pics are taken at a distance, so a long lens would be desirable, and IMO a priority for UFO hunters..
but, if you want to be prepared for every eventually, if there was a "close encounter", then you would also want something in-between. It sounds as
though you are all set with the 300mm (I'm guessing it's a "zoom"?), and the 50, which is a great general purpose lens to have, although I would
say a bit limited in it's possible applications in UFO photography ,unless you happen to be taking a tour of the interior of a craft
Long lenses..
First off, just to get something clear, there are two basic types of lens,
primes and
zooms. Prime lenses have a single, set focal
length, eg a 50mm f1:1.8 or 200mm f1:2.8. Zoom lenses can change their focal length, eg 80-200mm f1:3.5, which can be set to any focal length between
80mm and 200mm.
The reason I bring this up, is because the manufacture and design of lenses involves trade-offs, and in the case of zooms, which are more complex and
contain more optical elements than primes, more often than not optical performance at the long end is sacrificed along with light gathering
ability.
Primes on the other hand, tend to be lighter and faster, and because they are optimized for a single focal length they tend to be sharper too,
although there are exceptions to the rule. Keep in mind, that perceived "sharpness" is actually a combination of a number of qualities that lenses
have that can affect the appearance of your final image. "Contrast" (both macro- and micro-) is another important trait in a lens, and in a well
made lens should be high.
To cut a long story short, good quality long prime lenses (400mm f1:2.8 and above), are difficult to design, heavy, bulky, cost quite allot to
produce, and to make matters worse they need to have
rock solid support to be able to achieve their full potential. A sturdy tripod is a must,
and so is a good
head.. you don't want your $12,000 lens taking a nose dive, and it won't be easy to track a moving UFO if your head is not
up to the job - these lenses can weigh in excess of 5KG. Here's a quick list of Nikon primes to give you an idea (weight is in grams):
AI-S 400/2.8 IF-ED - 5150
AF-I 400/2.8 IF-ED - 6600
AF-S 400/2.8 IF-ED II - 4400
P 500/4 IF-ED - 3000
AF-I 500/4 IF-ED - 4200
A 600/5.6 P - 3600
AI 600/5.6 IF-ED - 2700
AI 600/4 IF-ED - 6300
A 800/8 P 5/5 - 3500
AI-S 800/5.6 - 5450
A 1200/11 P - 4300
So, if you really want to get it right first time round, get the
Wimberley head and a
good solid pod like the
Gitzo G-1325 at
least - in my experience this combo will work ok with a 600/4 plus 1.4x tele-converter
and good technique)
The good news is that you can get a good quality long prime lens for a bargain price, if you don't mind a lens that has seen some use, and may have
the odd scratch or ding, but usually this does not affect optical quality(lenses with large front elements, need large scratches, before you start to
see a difference). I'd recommend hunting around for a used 500/4 or even better 600/4. Ebay is a good place to start, and to get an idea of prices,
also
here.