Long Zoom 'Pecking Order'?

Hi,

Am I right in thinking that the Sigma 50-500mm at the long end is a better sharper lens than the Sigma 70-300mm? And, in turn, the Sigma 100-300 f4 is better than both of those?

And, I presume the Pentax DA* 300mm f4 is better than all of the above?!

I ask because I have a Sigma 70-300 APO, and whilst it's an excelent lens for the money, I am a little disappointed with the sharpness of it at 300mm. I do end up putting a 1.5x converter on most of the time to get 450mm, so would the 'Bigma' be a better bet at the equivalent zoom?

Part of me thinks saving a little more and getting the Pentax DA* might be the best option, but I'm really not sure! As long as I saw improvements from my exisitng lens, I'm sure I'd be happy with any of them.

Sorry for dragging up what I'm sure is a well worn discussion, but the searches of previous debates seemed inconclusive!

EDIT: Oh, and where does the new Pentax 55-300mm sit in all this?!

My own quest here was certainly conclusive.

Yes, I've read through that thread previously, and the conclusion seemed to be that the DA* 300mm was the better lens than the Sigma 100-300 f4.

But, I know that both those lenses blow the the 70-300mm APO out of the water with regards to image quality, so I suppose I'm more interested in the 'middle ground' if there is such a thing?

Is the Sigma 50-500 or the Pentax 55-300 a step in the right direction from a Sigma 70-300 APO? I'm guessing the 55-300 might not be, but what about the others?

A Sigma 135-400 and 50-500 are both much more expensive than my current zoom, so what do you get for the extra money?

The Sigma 70-300mm is very much a consumer zoom lens, as is the Sigma 135-400mm. I have both and have been pleased with them, particularly with the macro capabilities of the 70-300mm.

The Sigma 50-500 (Bigma) has a few followers here, but not me I'm afraid so I can't comment. Perhaps others will. My own opinion on price is that the Bigma, with it's 10:1 zoom ratio is more expensive to produce and to be honest, I think most owners will use it at the long end anyway. I can't see the point much of a 2.5Kg 50mm lens that needs a monopod/tripod for stability ? ? ? To that end, I'd prefer a 500mm prime for improved image quality.

The Pentax DA* and Sigma EX DG ranges are arguably 'professional spec.' lenses and really ought to be much better than consumer lenses, hence their prices.

Whilst I concluded that the DA* 300mm was the best option for me, that was mainly because I have the Sigma 135-400mm and Pentax 135-600mm lenses already, which is why I ruled out another zoom (Sigma EX DG 100-300mm). The Pentax lens is a bit lighter (about 400 grammes) and water/dust proof too.

Long lenses require high shutter speeds, and high shutter speeds require either high ISO or a wide aperture.

I would therefore always prefer a good long prime to a good long zoom. The wider aperture allows faster shutter speeds at low ISO.

And, as others have mentioned, long zooms tend to be used mostly at the extreme end, so there's not much downside to using a prime.

"Normal" zooms are another matter. Their full range tends to be used, not just the extremes, and high shutter speeds are not a requirement.

The Bigma may be impressive, but for most people two much lighter lenses covering the same range would be a better bet.

G

Thanks for your comments both, they are much appreciated, and are helping to clear my thoughts around where I go next zoom wise.

So, the conclusion I'm drawing near to is that the 50-500 is just a whole lot more lens to carry about, especially as I'll be using it at the long end. The f6.3 aperture at anything over 260mm will also hamper my low light shutter speed and the image quality will not necessarily be any better than I'm already achieving with my 70-300? Is that correct?

The next logical step then would be a prime zoom, like the DA* 300mm?

Can you also help clear my aperture confusion up please?!

Sigma 70-300 at 300mm f5.6 + Kenko 1.5x Converter (450mm) = f8?

Sigma 50-500 at 450mm is f6.3?

Sigma 50-500 at 500mm f6.3 + Kenko 1.5x Converter (750mm) = f?

Pentax DA* 300mm f4 + Kenko 1.5x Converter (450mm) = f5.6?

Is that right?

Thanks again!

Tooks,

A 1.5x t/con typically reduces the aperture by 1 stop, a 2x by 2 stops. So, a lens normally wide open at f/5.6 when fitted with a 1.5x t/con becomes f/8.

Duncan

Or to be exact (sorry, I'm a pedant ), a 1.5x converter reduces the light by just over a stop, so an f/5.6 lens would become f/8.4. A 1.4x converter would give a one stop reduction.

Dan

Ah ok, thanks both!

I've never used the Sigma 70-300, but I've always had the impression that it was on par with the FA 80-320.

The DA 55-300 makes the 80-320 look like a beer bottle.

It's well worth a look.