Originally posted by bertwert Yet another thread about long lens options... So I've been thinking of upgrading from my A 400/5.6 (or rather complementing it), as while it's an excellent lens there's a few modern amenities that would be nice to have...
I've thought through a couple ideas...
Getting the DA*300 and 1.4x but I'm a tad worried of AF reliability as well as speed/volume (if screw drive converted).
Getting an older Adaptall 300/2.8 and some TCs including the 1.7x for a bit of an AF experience - would be nice to have the wider aperture for close evening birds, but apart from that it shares several similar issues (or should I say qualities?) with the A 400.
A Sigma 300/2.8 and TCs - not very common to see for sale, expensive, reports of slow AF.
The raved about 55-300 PLM - need more speed and reach really.
Bigmas of various sorts - some better than others with regards to quality, and supposedly not sharp on the far end.
I don't think I'm missing any substantial option here?
Anyways, going through all those I think I'll be disappointed over time for some reason or other and wish I'd just gone for the 150-450... It fits the bill as to what I am currently missing, and as far as I can see it's only .
I did a comparison of my 300 to 500mm lenses, like a bigma 50-500, a m*300, a 55-300 f5.8, teleconvertors, a k400, a sigma 500 ex apo dg f4,5 and a (finally) a new acquired pentax150-450. Most older secondhand lenses acquired over time for prices (far) below 1/3 of the new price of the 150-450mm. In the end I decided to buy the 150-450mm and am happy about that.
Bottomline: the 150-450mm shines. In terms of sharpness the sigma 500 f4.5 is maybe a tad sharper but neglectable. It is a fantastic lens for birding and wildlife. It is a zoom with performance quite like a prime lens.
The only bad point is weight and size, it isn’t a lens to carry on a hike on a neckstrap. One can carry it by the tripod mount. (The sigma 500 is even worse as a tad longer).
Another good point : on aps-c the 150-450mm with pentax 1,4x remains impressive in sharpness and focussing.
The bigma has comparable use case as the 150-450mm but is slightly softer, still well performing, still much bang for the buck. It’s my backup to the 150-450 or 2nd long lens when using 2 bodies .
The next conclusion : I upgraded my pentax-m* 300mm to an A* 300mm to have a (much) smaller lens for hiking whilst avoid green button metering on the m*. For their size/performance both these lenses -even without autofocus- are unbeatable... (I never had the new pentax 300mm sdm but remains bigger and heavier).
And my old zoom 55-300mm f5.8 remains my 2nd travel lens for every light travel else than safari's.