View Full Version : 300mm f/4 + 1.4x or 100-400mm f/4.5-5.6

08-11-2010, 5:16pm
I am considering the 300mm f/4 L with a 1.4x teleconverter (making it 420mm f/5.6).

Would the image quality of this be comparable to to 100-400mm f/4.5-5.6 L at its extreme end of 400mm (I have read that its quality degrades at this end of its range) ?

08-11-2010, 6:16pm
I been told the same thing,that's why I'm not going to get the teleconverter for my 70-200mm

Cam Scott
08-11-2010, 8:59pm
As long as you can step down from 5.6 to 8.0 (obviously in good light) the 100-400 is much more versatile, but depends on what you're going to use it for! I'd love a 400 prime, but, 100% need the zoom for tracking dogs out herding.
The 300 plus 1.4X now 5.6, drop it down a couple of stops for the sweet spot, and, well you'll have a sharp lens, not fast though, and not as versatile as the zoom.

I like the 1-400 running 400mm, f/8 ISO 400, 1/1200 sec on a slightly overcast day. If I run f/5.6 ISO 200, I can notice the sharpness fall off. (5DII)
Can still live with it though.

08-11-2010, 9:17pm
Let me offer another suggestion. The 400/5.6L is incredibly sharp and has greater reach than the 300/4L IS.

A tele-converter will always degrade image quality to some extent (some lenses handle it better than others - the 70-200 isn't one of them).

Pros for the 100-400:
* Closer minimum focus distance
* IS (although it's not fantastic, being early generation)
* zoom

Pros for the 400/5.6L
* Light
* sharpest lens of the three choices at 400mm (or thereabouts)
* No push-pull zoom which can sometimes introduce dust into the lens

Pros for the 300/4L IS + TC
* Excellent IS
* Very sharp at 300mm
* Image quality still very good with 1.4x TC (although not as sharp as the 400 prime)
* choice of two focal lengths (300 or 420) albeit not without some mucking around

09-11-2010, 7:15am
Thanks Dave, that's the kind of response I was looking for.

I had considered the 400mm f/5.6L, but decided that image stabilisation would be of advantage at the 400mm range whilst being hand held, so it boils down to the 100-400 zoom or the 300 prime + teleconverter.

I am leaning towards the 300mm prime as it offers closer focusing distance (1.5m instead of 1.8m) and is faster at 300mm (f/4 compared to say f/5 or f/5.6). It would also have less barrel distortion than the zoom.
The only disadvantage is that it's not a zoom.

Main uses would be for birding and aircraft shots.

09-11-2010, 9:33am
Primes are awkward when you want to get a bit closer or further away - you have to walk - but then is that such a bad thing!

09-11-2010, 10:39am
Im trying to make the same decision (see the post near yours for new big lens for my kit).

the things you hear about the 100-400mm dropping sharpness at 400mm, from the test images ive found on the net, it still appears incredibly close to the 300mm f4 with 1.4TC.

tough decision, i dont know the answer, hence my post about the same thing

09-11-2010, 8:13pm
If it's for birds, I'd choose the 400 prime every time, as you will nearly always have the TC on the lens. And with birds, your really looking for as much clarity in shot as possible, and I don't think the 300 will give you with the TC. Though IS will help a little, I don't think it will make THAT much difference, technique will help more. An if you are going to be mounting it on a monopod/tripod you'll be turning off the IS anyway. I regularly shoot at 600 and it doesn't have IS and I have never missed it.
Oh yes, I used to own the 100-400 and sold it, not because it was bad, but because I only ever used it at 400, and intend on replacing it one day with the prime.

10-11-2010, 11:25am
Thanks Allann,

In regards to the 400mm f/5.6L prime, I have seen that it's closest focusing distance is 3.5 metres. That's more than double the afore mentioned lens.

If I choose the 400mm prime, I will be using it on a full-frame camera. Take a small bird, a butcher bird for example, at 3.5 to 4m distance, would this lens fill the frame with the bird ?

10-11-2010, 11:44am
If I choose the 400mm prime, I will be using it on a full-frame camera. Take a small bird, a butcher bird for example, at 3.5 to 4m distance, would this lens fill the frame with the bird ?

A butcher bird is by no means small, but yes you'd be getting reasonably close to filling the frame at 3.5 meters, if it'll let you get that close. A small bird like a wren or silvereye however, would not fill the frame, but good luck getting really close to these guys anyway. Unless you have a friendly bunch that are used to human interaction, these smaller birds will normally scatter or at least not behave naturally if your that close.

The 600 has a mfd of 6 meters, this is a little too far sometimes and I have used an extension tube to reduce that distance. But those times are few and far between. Generally I try and shoot at around 7-10 meters, this distance seems to allow for natural behaviour if your careful and also allows for enough detail and frame to make a great shot.

David may have some really close examples with the 400 prime that he'd like to share.

09-12-2010, 8:02pm
Well, I've bitten the bullet and am going for the 300mm f/4L IS + 1.4x teleconverter.

Thanks for everyones feedback.

My reasons:

offers 2 focal lengths (300mm + 420mm)
does not go lower than f/5.6 (good for reasonable viewfinder image and autofocus)
has image stabilisation (let's me shoot at a lower ISO)
has minimum focusing distance of 1.5m (can experiment with macro)

As I am not yet a serious 'birder' and also wish to dabble in macro, I think that this combination would suit. It also fits my budget.

09-12-2010, 8:37pm
A good compromise really. The 300/4 is very sharp and at f/4 the background blur you can achieve with it is excellent. I still reckon if you're chasing birds on a full frame camera, you'll be using the 1.4x TC all the time. It should take it ok though (primes are a lot more forgiving with TCs than zooms are).

Frankly though, 400mm on a full frame body can be too short for birds unless you can get very close. To give you an idea, here's a Kookaburra shot on a 5DII with the 400/5.6L at 4.23m away (not cropped).

http://farm5.static.flickr.com/4083/5043390595_73b37c8f88_b.jpg (http://www.flickr.com/photos/dadegroot/5043390595/)
Blue-winged Kookaburra (http://www.flickr.com/photos/dadegroot/5043390595/) by David de Groot (http://www.flickr.com/people/dadegroot/), on Flickr

As you can see, if it was on a smaller branch, and I could see it's tail, it'd fill the frame. Something smaller like a Butcherbird, you might get a similar frame at the min. focus distance of 3.5m. It is rare, however, that you'll get that close anyway.

13-12-2010, 8:28pm
I now have my 300mm prime and I must say it kicks arse over the 300mm consumer zoom I had previously. It's my first go at an IS lens and when it kicks in you really notice it.

Got home early and took some test shots, here is one:

f/5 @ 1/125 sec with IS on, 1600 iso, approx 1.5m focus distance

I'm still awaiting the 1.4x teleconverter.

Dave, I think your Kookaburra looks more unkempt ;)

31-12-2010, 8:20am
Well, I've bitten the bullet and am going for the 300mm f/4L IS + 1.4x teleconverter.

I have watched this thread develop without joining in to avoid treading on toes but I congratulate you on your decision.

I shoot mostly BIFs and have the full range of L telephotos from the 200 f/2.8 to the 600 f/4L IS and each has its preferred place, light hand held the 400 f/5.6 is undisputed king, best BIF on tripod with Gimbal head 500 f/4 + i.4 most versatile and superb IQ and almost Macro use the 300 f/4 with or without 1.4, you will not regret your decision.:)