which lense

[glsammy]

Originally Posted by Gaza

That's interesting. Boddie
What exactly were your findings? What were you checking for ? Length ? Image quality ?
Did you compare these lens with comparable ( length ) prime lens, for length ? If so what make of lens ?

I am interested, as it is soon time for me to purchase a new lens.

I've not tested the 100-400,but I did do many comparisons of the Canon 400mm and the Sigma 50-500mm.
Here's one of the samples I took which shows the difference in resolving power of the prime lens:




These were pixel sized crops taken from exactly the same distance.
The Sigma was set as close to 400mm as it's possible.(It always shows as 417mm.)
Note how much larger the Canon crops are, never mind how much clearer!
I personally think that Sigma over estimate the Bigma power, more like 470-480mm, and Canon under estimate theirs, more like 410mm. (This is not an accurate figure, just my guess!)
Despite this, I still ended up selling the 400mm and keeping the Sigma. Resolving power isn't everything. A zoom has many obvious advantages and even though I'm getting another 400mm, I'll certainly keep and use the zoom on occasions.

[Gaza]

Hi glsammy

Thanks for your time and effort. Very much appreciated.
I always wondered, how much better a prime lens could be.
I knew that there would be a difference, but didn't realise, that it would be that big, a difference.

I am 100% convinced that I need a prime.

As luck would have it. I was given the green light to purchase a prime, today.
Now I just have to make up my mind Which one !

Its either going to be the Canon 400mm f5.6 or Canon 300mm f4.0 image stabilised.

Forgot to ask. What camera were you using for these ? Full frame ?

[glsammy]

No, it would have been my 20D or 40D.
I've also had the 300mm F4. It was the equal to the 400mm F5.6 so far as resolving power. It works well with a 1.4X TC, even with that it still gets better detail than the Bigma. It also has a good close up range, focuses down to 1.5 mtrs so it's excellent for Butterflies and even Damselflies.
Here's a shot I took with the 300mm and a kenko pro 2X TC:

The only problems I had with it was the AF performance with the 1.4X TC. I found it far too slow and unreliable, and the IS. On my camera the IS slowed the continuous shooting rate and I generally didn't like it. I ended up switching it off altogether. It all depends on what you want the lens for. For birds, especially if in flight, then the 400mm F5.6 wins hands down.
The 300mm F4 will also perform well with birds, even with a 1.4XTC but that missing 100mm is hard to ignore. If you can get the bird in range and they're not flying,then you'll have no problems with the image quality it can give.
As you can see from this I've tried many lenses and now I've decided yet again that the 400mm F5.6 is the best for me. I did consider the 300mm F2.8, but the cost was just too much for the benefits it gives.
That's not to say I won't change my mind yet again in future.

[operatorcamera]

thanks ever so much for taking the time to reply to my post.
the motorcycle goes first jim and then i will be selling my olympus gear
trevor.

[Gaza]

Originally Posted by glsammy

No, it would have been my 20D or 40D.
I've also had the 300mm F4. It was the equal to the 400mm F5.6 so far as resolving power. It works well with a 1.4X TC, even with that it still gets better detail than the Bigma. It also has a good close up range, focuses down to 1.5 mtrs so it's excellent for Butterflies and even Damselflies.
Here's a shot I took with the 300mm and a kenko pro 2X TC:

The only problems I had with it was the AF performance with the 1.4X TC. I found it far too slow and unreliable, and the IS. On my camera the IS slowed the continuous shooting rate and I generally didn't like it. I ended up switching it off altogether. It all depends on what you want the lens for. For birds, especially if in flight, then the 400mm F5.6 wins hands down.
The 300mm F4 will also perform well with birds, even with a 1.4XTC but that missing 100mm is hard to ignore. If you can get the bird in range and they're not flying,then you'll have no problems with the image quality it can give.
As you can see from this I've tried many lenses and now I've decided yet again that the 400mm F5.6 is the best for me. I did consider the 300mm F2.8, but the cost was just too much for the benefits it gives.
That's not to say I won't change my mind yet again in future.

I cant thank you enough, for this info, Graham
It has given me, the answers to a lot of questions.
And has helped me decide, which way to go.
Again, thanks for your time and help.
Garry