[audiobomber]

Is it internal or external focus?

The 55-300 is not IF and does not lose range below infinity focus. I don't have a Sigma 70-300, but anyone I've heard of who owned both considered the Pentax to be an upgrade because of improved sharpness at 300mm. I "upgraded" from the Tamron 70-300 and never regretted it.

If you think you will miss the Sigma's macro feature, add a Raynox DCR-150. It will go from 1:3 to well beyond 1:1.

[Rondec]

I don't really have a big desire for this lens over my current 55-300. I guess the big two things are the new coatings (which I don't believe would make a real world difference) and the weather sealing (which I would like to have, but I don't really shoot with this lens in the rain very much).

[snake]

It's lame from a perception standpoint. Canon has had the EOS system since the 80s. Lenses that make a lot of noise may be off-putting for sone users.

Personally, I don't mind much. I'm more concerned with optical performance and focus accuracy.

That, I perfectly understand. From a performance standpoint, screwdrive from Pentax is really superb. And people are discovering this in converting, sometimes preventatively, their SDM lenses and getting some gains in speed.

Supposedly, the K-3 has a quieter SD motor.

[Rondec]

That, I perfectly understand. From a performance standpoint, screwdrive from Pentax is really superb. And people are discovering this in converting, sometimes preventatively, their SDM lenses and getting some gains in speed.

Supposedly, the K-3 has a quieter SD motor.

There is always a trade off. My perception is that lenses like the FA limiteds will last for a long time, while any lens with a motor in it, is significantly more likely to fail at some point. In Canon's consumer grade lenses, the only thing you gain is quieter operation, as the motors aren't particularly potent.

I really hope Pentax keeps screw drive lenses -- at least for primes. I also hope that for pro type lenses, they come up with a faster ring motor than current SDM lenses have. Quiet is fine, but speedy is probably just as important. Anyway, have you all heard the shutters on a 5D Mk II or D800? They aren't exactly quiet...

[kh1234567890]

I really hope Pentax keeps screw drive lenses -- at least for primes. I also hope that for pro type lenses, they come up with a faster ring motor than current SDM lenses have. Quiet is fine, but speedy is probably just as important.

A lot could be done by tweaking the camera firmware. The major problem with screw drive on lenses with long focus travel, such as the DA 55-300 or the DA 35 Macro is that if the camera misses the focus point then it stupidly spins the focus until the end stop, which can take a while.

[audiobomber]

A lot could be done by tweaking the camera firmware.

I don't think that hunting and long focus throw can be fixed in firmware. How would the camera know it has missed focus? A focus limiter would work, but I'd rather have quick-shift.

One thing I do to mitigate 55-300 hunting is to return the lens to infinity focus after each series of shots. If nothing is in focus, the lens will always start looking by cycling inwards. If it misses the target, it will go all the way to the stop and start back toward infinity. IME, it will rarely find focus while racking from close-up to infinity, so I don't hesitate to use quick-shift as soon as focus is missed the first time. Anyone with a DA L model better be ready to switch to manual focus, or face a lot of frustration.

[cali92rs]

Is it internal or external focus? (Does the front element move in and out as it focuses) the big thing for me with the 70-300, is for close ups, that barrel extends way out in front of the body of the lens, creating more magnification, the closer you get, without that, I'm probably better off using my 60-250.

Just curious, with your 60-250mm, are you looking at this lens just to lighten your load?

[normhead]

The Sigma 70-300 gives me superior magnification at 12 feet, out preforming the 60-250 simply because the image is so much bigger. My 400 extends its the barrel of when focusing magnification, so for many shots from my porch blind, Blue Jays and Woodpeckers, the A-400 is too long, the 60-250 at 250mm is too short. Right now my compromise lens is my F70-210. I think I should be able to do better.

[Heie]

It's up!



HD 55-300 WR In-Depth Review

-Heie