Does anyone own or has used both of these long lenses?

[Phal]

Canon 400mm F2.8L + converters 1.4x and 2x vs Sigma 300-800mm


Obviously one is zoom whilst the other isn't. One is F2.8 and the other is F5.6. Currently these lenses are a bit more of a wish than anything else but I definitely intend on getting one of them at some point!

I like the idea of having the versatility of the zoom and not having to detach the camera to add/remove converters etc but how different are they in terms of quality? I can look at shots but it's hard to tell what PP has been applied sometimes or whether it's just a crap shot.

Any other lenses to consider?

 

[Phal]

Thanks for that I do find myself using my 100-400 at 400mm and I still want more reach so I need something eventually!

The Sigma really appeals to me despite the size and weight. Having used my 100-400mm quite a lot I know how convenient being able to zoom is.

That new Tamron 150-600mm might be tempting to tide me over for a while as it's likely to be reasonably priced but F6.3 will mean it's only much good on a sunny day!

Maybe some new magical lens will be released by the time I can afford one lol

 

[Phal]

Well I rarely use my 100-400mm without the tripod so I definitely wouldn't be trying to handhold anything longer too often hehe.

Current tripod is rated high enough for the weight of bigger stuff but I know it wouldn't be stable enough for any longer exposures. It would be there more just to stabilise things.

I plan on renting a 300-800mm for a weekend or something to see what's involved in using it. I can then see if I'm manly enough to cart it around lol

 

[Phal]

Manfrotto 055CX Pro4 which is rated up to 8KG according to the Manfrotto site and the Hydrostatic head is rated to 16KG

It would hold the weight without any issues imo but clearly it wouldn't be steady enough for a 30 second exposure at night or something daft! Fair enough trade-off as far as I'm concerned! If the lens is 6KG then I don't need much more to lump around.

I guess when I rent it then it'll be a good test to get an idea of what I can expect!