Sigmonster or great white?

[K-Lex]

I am buying a new lens - predominantly for birding and also for other mammals. Question is, should I get the Canon 500 f4 and the Canon 1.4x TC (to use on my 70-200 2.8IS) or the Sigmonster 300-800 f5.6? Opinions welcomed...

[postcardcv]

I had a similar choice to make last year (also considered the 600 f4) and went for the Canon. With a 1.4x the Canon gives you almost as much reach and you get IS into the bargain. The Canon will also focus 1.5m closer (can make a big difference) and weighs ~2kg less which will definitely notice at the end of a days use. I had an interesting conversation with someone and a well known camera retailer who told me that they regularly got the 300-800 traded in and it was almost always against a 500 f4.

[Marcus Conway - ebirder]

Interesting. I have always wondered why I don't see the sig monster as much as expected. There must be some reason why.

[reptilian]

well, from a long time sigmonster owner, i for one would not part with mine.
ok, occasionaly i miss having image stabilisation, but i use a heavy duty tripod with a kirk king cobra head and i have no problems with this set-up. the weight of the lens being counter balanced with the cobra head is amazing. you can swing it around with your little finger very easily. and couple this with a remote shutter release and its awesome.
i like the extra reach you get with the sigmonster. for example, at gigrin farm i use the lens at no more than 600mm for frame filling shots, and its nice to have an extra 200mm spare to play with.
i also get good results from using a bean bag (large size off ebay). it is only when i am using a bean bag in low light situations when i miss i.s. occasionally.
the sigmonster is super sharp and i cannot fault the optics at all. even shooting at 800 mm at f5.6 the results are staggeringly sharp. i also am impressed with the results of sticking a kenko pro 300 dg 1.4x t.c. on the lens. you get even more of an awesome range.
one thing though that is worthy of note and you should take into consideration is the weight of the sigmonster. this lens is amazingly heavy. i would strongly recommend you check out the weight of this lens physically. the canon lenses are a lot lighter. two of my mates have the canon 500 f4 and they can carry the lenses around by hand quite easily. if i carry the lens around by the tripod mount then after a short time it feels like your fingers are being prised off with the weight.
i think of the sigma as an ambush lens. if you like to stay in one position, as in hides, then the sigmas weight is not really an issue (unless you have to carry the sigma 6 miles to get to the hide). but if you intend to carry the lens around all day then you could quite easily get tired of it. i carried the sigma all around skomer last year by hand and afterwards i felt like i had done a major workout with arnold schwarzenegger. and i am quite physically fit.
i have since added a strap to the lens and carry it around on my shoulder these days and admittedly this helps.
the only bag that i know of that will take this lens is the lowepro supertrekker aw11. although very well made, this bag is quite heavy on its own. so with the sigmonster in it plus other accessories you are talking about a very heavy combo and believe me you dont want to trek too far with this weight. (mind you, it saves you a fortune on gym fees! lol)
well, thats my input into this. i love the lens and its capabilities, but the weight is heavy. if your a youngish bloke and quite fit then you may not mind too much, but as i do not know your age then seriously i would handle one first before you make your choice.

[Romy Ocon]

I use both the Sigmonster and 500 f4 IS for birding, and IQ is equivalent at 500 - 700 mm. Beyond 700 mm, the Sigmonster can get more detail in the frame.

The 500 f4 IS is hand holdable, has faster AF (in AI servo), is weather sealed, is lighter and can shoot at f/4 natively (useful when you really need the light). But it's a prime of course, and thus no framing flexibility except by using TCs or varying the distance to the subject.


The Sigmonster is prime-sharp and has framing flexibility. But it's heavy, no IS, not weather-sealed and no focus limiter switch to speed up AI servo.


For me, these lenses complement each other. I use the 500 for hand helds, shots from the car and for BIFs. I prefer the Sigmonster when I can use a tripod, particularly for long shots needing 800-1600 mm, or for hide work when the shooting distance varies a lot on account of subject movement. Each of these lenses is better than the other in its areas of strength, and I use the tool appropriate for the requirement of the job.

Romy

[Cashie]

Well K-lex, I have a 500 f4 & my friend has the sigma 300-800 f5.6 & he keeps asking me if I want to swap, but I certainly wont do that!!

When I use the 1.4X extender on the 500 you cant tell it's on there the IQ is brilliant.