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Comment by RJ posted on SWAP lowepro flipside 300 at 21/10/2014 - 11:43
Received all three AF280T flashguns in excellent condition. I really wash't expecting them to be this good considering their age - a bargain. Thank you very much.
Regards,
Rod
Regards,
Rod
Comment by RJ posted on FS: Various accessories - 25 items !!! at 31/08/2014 - 21:00
cabstar wrote:
The da 35mm 2.4 is super fast as it has a really short focus throw, for the same reason the da* 50-135mm is slow to focus as it has a long focus throw.
Seems to make sense in theory but my DA14mm f2.8 is slower to focus than the old F35-70 f3.5-4.5.johnriley wrote:
It will depend on the lens in question and the type of construction.
The SMC Pentax-DA 40mm f/2.8 Limited is blisteringly fast for example, presumably because the focusing has such a short throw. The 55-300mm has a lot more work to do.
Was just going to post this and saw John's reply.It will depend on the lens in question and the type of construction.
The SMC Pentax-DA 40mm f/2.8 Limited is blisteringly fast for example, presumably because the focusing has such a short throw. The 55-300mm has a lot more work to do.
The da 35mm 2.4 is super fast as it has a really short focus throw, for the same reason the da* 50-135mm is slow to focus as it has a long focus throw.
Comment by RJ posted on F & FA lens focus speeds at 03/10/2013 - 15:16
Mongoose wrote:
I'd bet that a DA 55-300 on a K5II is still faster focusing than an f70-210 on an SFX
Yes, this makes sense. I couldn't understand why Pentax would design a backward step in terms of auto focus speeds. But if, as you say, it might be because of smoother manual focus and non rotating front elements then this makes sense.RJ wrote:
this is a guess again, but because people didn't like the manual focus feel of the F series. Their focus is so loose and the throw is so short that they are very hard to focus manually. Also, people wanted features like non-rotating front elements and quick-shift focus clutches, all of which increase the complexity of the drive train and therefore make it slower.Mongoose wrote:
the Fs tend to be fast, I suspect because they're designed to work with the very early SAFOX bodies, consequently the lenses are designed for auto focus speed almost at all costs.
I don't understand then why Pentax didn't continue with the fast auto focus speeds when they developed the FA and DA series.the Fs tend to be fast, I suspect because they're designed to work with the very early SAFOX bodies, consequently the lenses are designed for auto focus speed almost at all costs.
I'd bet that a DA 55-300 on a K5II is still faster focusing than an f70-210 on an SFX
Comment by RJ posted on F & FA lens focus speeds at 03/10/2013 - 15:09
Payment sent.
Comment by RJ posted on pentax F 70-210mm at 27/09/2013 - 13:48
You have a pm.
Comment by RJ posted on pentax F 70-210mm at 27/09/2013 - 12:53
Arrived today and nicely packaged too. Thanks Andrew.
Comment by RJ posted on FS: CAMLINK CIRC-POLARIZING FILTER 49mm at 23/09/2013 - 17:45
Russ wrote:
F70-210 is really speedy and great optics to boot
The newer lenses, like the 55-300, make a lot of noise but not very quick. The 50-200WR was a lot better than the 55-300 though.
The 18-55WR seemed okay too, quite nippy and no fuss.
So the F70-210 is faster than the 50-200WR?F70-210 is really speedy and great optics to boot
The newer lenses, like the 55-300, make a lot of noise but not very quick. The 50-200WR was a lot better than the 55-300 though.
The 18-55WR seemed okay too, quite nippy and no fuss.
Comment by RJ posted on F & FA lens focus speeds at 21/09/2013 - 18:30
Mongoose wrote:
the Fs tend to be fast, I suspect because they're designed to work with the very early SAFOX bodies, consequently the lenses are designed for auto focus speed almost at all costs.
I don't understand then why Pentax didn't continue with the fast auto focus speeds when they developed the FA and DA series.the Fs tend to be fast, I suspect because they're designed to work with the very early SAFOX bodies, consequently the lenses are designed for auto focus speed almost at all costs.
Comment by RJ posted on F & FA lens focus speeds at 21/09/2013 - 18:29
An F version exists at a constant aperture of f4. One for sale here but looks a bit on the high side to me.
Comment by RJ posted on sigma 24-50 f4-5.6 at 21/09/2013 - 16:20
