How does a fixed 400mm lens work?

Kryptix

Kryptix

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I've got a fixed 50mm lens and I don't find much use for it because it has no zoom. It's rare that I'm in a position where 50mm is the perfect zoom.

I imagine 400mm would be stupid, how often would something fit perfectly into 400mm?

Surely it can't work like that... Am I missing something?
 
These lenses are best used where you can control, to a degree the composition. Wildlife for example...if you are concentrating on birds, set up a perch where the composition is right, then sit..and wait :D

If it is sport, then position yourself in the relative place where composition is good for where you expect action to happen!
 
Kryptix said:
Surely it can't work like that... Am I missing something?
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"Fixed" or prime lenses, to use the normal terminology, offer improved quality (within similar pricing structures) and normally have a larger maximum aperture when compared to a zoom covering the same focal length. Zooms are designed around many compromises whereas prime lenses benefit by not needing the extra internal elements that inevitably lead to increased aberrations.

Back to your question..."am I missing something?".....yes, you are....and one day you'll find it.

Bob
 
FeetDtl.jpg

:D:D
 
Kryptix said:
I've got a fixed 50mm lens and I don't find much use for it because it has no zoom. It's rare that I'm in a position where 50mm is the perfect zoom.

I imagine 400mm would be stupid, how often would something fit perfectly into 400mm?

Surely it can't work like that... Am I missing something?
Click to expand...

I think you'll find that typically 400mm is the minimum length people may need for a lot of photography - especially wildlife. The price leap beyond 400mm is pretty dramatic so for many people 400mm is a realistic maximum. There are also issues of weight and size to consider and the biiger/heavier the lens, the bigger, heavier and more expensive the tripod and head need to be. I'm sure many people with 400mm lenses would love 500mm or 600mm or even 800mm but we can't all have what we want.

That said, I have chosen to have a 100-400 zoom rather than a 400mm prime and for my tastes that gives me a more flexible lens that gives me more options. The downside compared to the 400mm f/5.6 prime is in ultimate IQ, especially wide open, and also in focusing speed. I must admit that I am at the 400mm end a lot, sometimes with a teleconverter, but I also use the full range of the zoom too, so overall it is the better choice for me.
 
tdodd said:
I think you'll find that typically 400mm is the minimum length people may need for a lot of photography - especially wildlife. The price leap beyond 400mm is pretty dramatic so for many people 400mm is a realistic maximum. There are also issues of weight and size to consider and the biiger/heavier the lens, the bigger, heavier and more expensive the tripod and head need to be. I'm sure many people with 400mm lenses would love 500mm or 600mm or even 800mm but we can't all have what we want.

That said, I have chosen to have a 100-400 zoom rather than a 400mm prime and for my tastes that gives me a more flexible lens that gives me more options. The downside compared to the 400mm f/5.6 prime is in ultimate IQ, especially wide open, and also in focusing speed. I must admit that I am at the 400mm end a lot, sometimes with a teleconverter, but I also use the full range of the zoom too, so overall it is the better choice for me.
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Cheers -- helpful post. :)

I can only judge it on my 70-200mm and the only time I'm at 200mm is when I need more zoom and I'm planning to crop the picture. Normally I'm at like 195mm or something. I've never zoomed straight in to 200mm and thought it was perfect. I can't imagine using a fixed 400mm lens but it may be a lot easier than it seems if you haven't ever used/seen one.

I would too prefer the 100-400mm L and I think I'll buy one soon. How much difference is there in IQ? I'd love to see 2 photos both at 400mm. :)
 
my old nikon 80-400mm compared to a 300mm with a 1.4x converter are miles apart in IQ!!!! especially when you need to shoot wide open to get some speed, then it really shows big time
 
Kryptix said:
I would too prefer the 100-400mm L and I think I'll buy one soon. How much difference is there in IQ? I'd love to see 2 photos both at 400mm. :)
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Old shots, but all with the 100-400L

4336_92657688946230355b744f.jpg


4336_417063713462519360b047.jpg


4336_470106934627ac5e747e6.jpg
 
Kryptix said:
I'd love to see 2 photos both at 400mm. :)
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Here's one at 400mm and wide open at f/5.6, taken with my 40D. This is unedited....

20080803_141208_6391_LR.jpg


Here's a 100% crop, again with no edits....

20080803_141208_6391_LR.jpg


Although I wouldn't recommend trying to expect great IQ viewed at 100%, here's an attempt to tweak the 100% crop a bit - basically just a WB correction and some sharpening adjustments in Lightroom....

20080803_141208_6391_LR.jpg


Here's another example, taken with my 50D and the 100-400 at 400mm with a Kenko 1.4X teleconverter attached. See what I mean about always wanting more length for wildlife. This is tweaked in Lightroom...

20081122_112845_1795_LR-3.jpg


100% crop....

20081122_112845_1795_LR-2.jpg


Hopefully someone can post an image or two from the 400mm prime.
 
That's some crop! (the starling) does the 100-400 AF with the 1.4 Kenko?
 
2600968130_72c65c7f35_b.jpg


this was taken with a 400l i have both the prime and zoom and there is not a lot in it really
regarding iq the prime is a lot lighter and much better for bif shots but the zoom is more versatile
also the 100 400 is not a true 400 slightly less compared with the prime
 
i prefer to work with primes but then again zooms have their place and not knocking them. I will probably looking at a 300mm prime next.
 
CT said:
That's some crop! (the starling) does the 100-400 AF with the 1.4 Kenko?
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On the 50D (and anything else other than a 1 series) you need to tape the pins on the teleconverter to fool the camera into thinking there is no teleconverter present. Otherwise the camera will flat refuse to even try to AF - f/5.6 + 1.4X = f/8 which is outside spec. With the pins taped, AF performance is actually quite good on the outer diagonal focus points, at least for static subjects. The other outer points aren't too bad either, but the centre point is all but useless. I haven't tried tracking a BIF with the teleconverter in place.

Which pins to tape - http://k43.pbase.com/o4/49/201349/1/57320282.kenko.jpg

I do have a 1D3, which will AF with the teleconverter present and reporting, but then the camera limits focus to the centre point only and, although I haven't put it to the test in the field, I hear that AF performance is degraded with the teleconverter in place. Basically, f/8 is a bit pants altogether for phase detect AF because there is barely enough differential in the light paths for the camera to work out what to do - f/8 is simply too narrow.
 
Kryptix said:
I've got a fixed 50mm lens and I don't find much use for it because it has no zoom. It's rare that I'm in a position where 50mm is the perfect zoom.

I imagine 400mm would be stupid, how often would something fit perfectly into 400mm?

Surely it can't work like that... Am I missing something?
Click to expand...

Canon Bob touched on this, remember that your 50mm is f1.8, your zoom is f4. Primes are generally 'faster', they have larger apertures which makes them better at shooting in low light, and isolating subjects with a shallower depth of field.

Years ago when I started taking photographs zooms were not as good as they are these days, so if you wanted quality a prime was the way to go.
 
I think as others have said that its the quality of a fixed focal length lens that is the difference,I have a Sigma 70-300 that is ok and a 41 year old Vivitar 300mm lens that I paid £18 for and it is bitingly sharp even wide open as I hope the following shows

KfordPark18010923.jpg
 
tdodd said:
On the 50D (and anything else other than a 1 series) you need to tape the pins on the teleconverter to fool the camera into thinking there is no teleconverter present. Otherwise the camera will flat refuse to even try to AF - f/5.6 + 1.4X = f/8 which is outside spec. With the pins taped, AF performance is actually quite good on the outer diagonal focus points, at least for static subjects. The other outer points aren't too bad either, but the centre point is all but useless. I haven't tried tracking a BIF with the teleconverter in place.

Which pins to tape - http://k43.pbase.com/o4/49/201349/1/57320282.kenko.jpg

I do have a 1D3, which will AF with the teleconverter present and reporting, but then the camera limits focus to the centre point only and, although I haven't put it to the test in the field, I hear that AF performance is degraded with the teleconverter in place. Basically, f/8 is a bit pants altogether for phase detect AF because there is barely enough differential in the light paths for the camera to work out what to do - f/8 is simply too narrow.
Click to expand...

I was aware of the taped pin trick. I did try it on the 2XTC with the 500mm and 50D, but while the AF hunted back and forth like crazy, it just wouldn't lock on to anything. It's doubly annoying because it seems to work for some and not for others.
 
Kryptix said:
I imagine 400mm would be stupid, how often would something fit perfectly into 400mm? Surely it can't work like that... Am I missing something?
Click to expand...

Yup, you are missing a lot. Most serious motorsport togs will use a long prime because its sharper and faster focusing than any zoom. Its only got one focal length to be optimised for, so its going to be bang on.

Yes everyone used to a zoom is going to scratch their heads at how is it possible to use it, but its perfectly possible, you just have to move yourself around.

Once you've seen the results you won't want to be playing with zooms, unless things are close up...

BTW the nifty fifty isn't really a good comparison to make... a Canon or Nikon long prime is an amazing piece of engineering, not a 30 quid plastic toy :thumbs:
 
I have a 400/5.6 prime as my "lightweight" wildlife lens. I chose it over the 100-400 for a number of reasons:

1. Cheaper
2. Lighter
3. Faster focusing
4. Image quality - I've seen some good stuff from the 100-400 but they seem a bit hit and miss. The 400/5.6 is stunning
5. Less to go wrong

I don't use it often as I normally carry bigger lenses but it has let me get shots like this:

captive_kestrel_lure.jpg


Which need focussing that is super fast and very accurate (Oh and some skill from the photographer :p)

Paul
 
Kryptix said:
I would too prefer the 100-400mm L and I think I'll buy one soon. How much difference is there in IQ? I'd love to see 2 photos both at 400mm. :)
Click to expand...

I can't believe I forgot the lens archive over on POTN. Check out these threads for examples from the 1-4 and 4....

100-400 : http://photography-on-the.net/forum/showthread.php?t=373778

400/5.6 : http://photography-on-the.net/forum/showthread.php?t=241053

You could also see what Pixel Peeper drags up....

100-400 : http://www.pixel-peeper.com/lenses/?lens=589

400/5.6 : http://www.pixel-peeper.com/lenses/?lens=31
 
grumpybadger said:
I have a 400/5.6 prime as my "lightweight" wildlife lens. I chose it over the 100-400 for a number of reasons:

1. Cheaper
2. Lighter
3. Faster focusing
4. Image quality - I've seen some good stuff from the 100-400 but they seem a bit hit and miss. The 400/5.6 is stunning
5. Less to go wrong

Paul
Click to expand...
Well said and just the reason why I went for the prime 400 f5.6L and I'm very impressed with it too.
 
^^^ You've got a cracking copy of the 100-400 there mav!
The first shot is an superb. I must admit to being a prime fan, but no-one would be dissapointed with results like that.

cheers
Bill
 
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