3 replies to this topic

[M.Beier]

Food for thoughts.

 

Time to learn more about optics.

We all admire our 70-200, and our primes - it does not move on the outside when zooming, when focus... Why oh why can't they make all lenses this way?

Many of us have 24-70 (or alike) for daily go-to lens, but, any options of which you don't get the "dust inviting" zoom?
I have a hard time figuring why they cannot make all lenses in a version with the feature of no moving parts externally.

Price? Heck, I'll gladly pay another 200-300 Euro to avoid having to worry about sealing - my 70-200, I wouldnt care if it was snowstorm, I'll still use it without a worry.....

 

Sorry for poorly composed thread.

[Merco_61]

Both IF and conventional lenses have disadvantages.

IF lenses are much more complex as the elements need to reconfigure themselves for each distance. This complexity makes them more fragile and prone to decentering unless they are built like tanks. CRC lenses do that as well, but to a lesser degree and only for close focusing. They don't give a constant field of view as they need to be focusbreathers for the focus to work. 

Conventional lenses are more difficult to weatherseal and need more power in an AF system as there is more glass to move.

 

The dust-pump zooms are another matter. It is much more difficult and expensive to make a wide-to-tele zoom lens that doesn't change length than a tele- or a wide-angle zoom. That is why the 24-70 is the only "dustpump" in the Nikkor trinity. The stroke is small enough that a double wiper seal works well to weather seal it. The cost of making a lens constant-length is as great a factor as the faster glass when comparing the 200-400 and the 200-500.

[M.Beier]

Both IF and conventional lenses have disadvantages.

IF lenses are much more complex as the elements need to reconfigure themselves for each distance. This complexity makes them more fragile and prone to decentering unless they are built like tanks. CRC lenses do that as well, but to a lesser degree and only for close focusing. They don't give a constant field of view as they need to be focusbreathers for the focus to work. 

Conventional lenses are more difficult to weatherseal and need more power in an AF system as there is more glass to move.

 

The dust-pump zooms are another matter. It is much more difficult and expensive to make a wide-to-tele zoom lens that doesn't change length than a tele- or a wide-angle zoom. That is why the 24-70 is the only "dustpump" in the Nikkor trinity. The stroke is small enough that a double wiper seal works well to weather seal it. The cost of making a lens constant-length is as great a factor as the faster glass when comparing the 200-400 and the 200-500.

Thought the 14-24 was a dustpumper as well.

And once again, thank you for your great response.

 

The focus breathing could indeed be an issue..

 

Jumping entirely in matters...

My Tamron 150-600, is Nikon 200-500 F5.6 a worthy change? I heard a lot about it, but I am yet to see them head to head or even see DxO do work on either of them.

[Merco_61]

The 14-24 moves a little (4 mm), but inside the substantial fixed hood with firm seals. It is not quite a fixed-length, but not a dustpump either.

 

The jury is still out when it comes to the four consumer supertelezooms. It seems that the sample variation is greater than the variation between the four. That might be why there are no full scientific tests of any of them yet. I have borrowed samples of all four and played with them a bit. I lean towards either the Nikon or the Sigma S as they focus faster on my gripped D700, but that might be sample variation as well. I can't choose between them from a picture quality point of view as they all have slightly different strengths and weaknesses. I will probably get the Sigma as the tripod mount doesn't have the slim and elegant 45° resonance-inducing idiotic geometry of so many Nikkors.