[Anvh]

Our 200 and 300mm DA*'s started off on the 2006 roadmap as DFA's with no star designation. I think you'll see a star get attached to the 550 when it's released.

Lets hope so, that would mean weather sealing and such a lens is only usable outdoors.

[SteveM]

Ouch, talk about a razor thin DOF ...

Which also means you lose resolution on such an aperture value on an APS-C sensor. A pity

That shot isn't bad...it gets much worse at longer focal lengths so a 550 + a TC, and depending on how close you are to the subject, you may end up with only a slice of the bird in focus...

I don't see any noise at all. My senses are pretty good at seeing noise in photos and I think that is something I learned to spot. I see noisy photos on flickr all of the time.

That shot was run through denoise....but the original was very good.

[dane.dawg]

I cant wait for this lense.. I hope the price is around 3k because i really cant afford the sigma 500mm f4.5..

[Bob from Aus]

Prices - My Sigma 500 purchase 6 months ago was $5000. I would think that is the absolute minimum discounted price a new quality Pentax lens would be sold for. If Pentax comes up with anything extra fancy you could be up near the $10,000 mark. pentax patented a long telephoto design that could be dismantled in half for easy transport.

I suspect they the lens design will be a balancing act;
1. Based on an old design it will be cheaper
2. Focusing motor will add to the cost
3. If they don't go for an old design will they have a FF in the future - could make it lighter and cheaper for a APC

My guess is if they make an expensive long tele lens then they are seriously considering FF
If its a cheap long tele lens then they have limited interest in developing a FF

[Paul Ewins]

The format size - APS-C vs 35mm - won't make much difference to the overall size and weight since that would all happen at the rear end of the lens. The front end, which is where all the big, heavy elements are, would be exactly the same size. If they are going to dust off an old design the best place to start would be the A* 600/5.6 for 645 and make two versions, one for 645 (full frame) and one for 35mm with common optics at the front and different optics and AF mechanism at the rear. This is the approach taken by Schneider and Komura in the past for their telephoto lenses which were available in both 4x5 and 35mm versions. FWIW, prior to the introduction of the 6x7 500/5.6 you could get a modified version of the 500/4.5 for the 6x7 mount. The optics weren't changed, just a shorter mount tube and removing a baffle.

Regardless of how it is labelled I expect the new super-tele to cover FF.

[Bob from Aus]

Regardless of how it is labelled I expect the new super-tele to cover FF.

thanks for your view. It adds a lot of information to this discussion.

[kindakaa]

My prediction:

• Pentax announce this lens as the most compact and lightweight supertelephoto lens in the world.
• Compact and Weather Resistant - for example Pentax DA 550mm F5.6 ED [IF] WR; Weight 1500 g. (without SDM)

[Sinister]

My prediction:

• Pentax announce this lens as the most compact and lightweight supertelephoto lens in the world.
• Compact and Weather Resistant - for example Pentax DA 550mm F5.6 ED [IF] WR; Weight 1500 g. (without SDM)

I'd love to see a Pentax DA 550mm F5.6 ED [IF] WR.

[trublubiker]

AFAIK, Pentax haven't made a prime over 200mm that wasn't a full hundred mms in focal length

ie, 200mm, 300mm, 400mm, 500mm, 600mm etc.

I often wondered if this was something to do with optical formulae.

When I saw the lens roadmap and the dot at 550mm I guess I assumed that a final decision hadn't been made as to whether it was going to be 500mm or 600mm.

As I said earlier, a 500mm f5.6 with the higher usable ISO on my K5 will do me just fine.

[Blue]

A slower lens isn't a crippled one.

IMHO, fast lenses like 300/2.8 or 600/4 are a thing of the past. Not because they are expensive (they are). But because modern bodies with their ISO capabilities and SR simply don't need it to a degree that the burden to carry and handle them is justified. Sport events from a predetermined position using a tripod may reain the only exception. But those arevTV events with good light, so ...

Assuming the lens is tack sharp fully open, I consider F5.6 (or F5.4 if an AF TC requires it) to be the new sweet spot.

ISO is just one aspect when using a big slow lens in nature work. If the af is near perfect, maybe. However, if manual focus is required, the bigger the aperture the better!

Plus, I notice you list it as a DFA* when the roadmap lists it as a DA without an asterick. I hope it is a weather sealed lens without the sdm.

[Blue]

AFAIK, Pentax haven't made a prime over 200mm that wasn't a full hundred mms in focal length

ie, 200mm, 300mm, 400mm, 500mm, 600mm etc.

I often wondered if this was something to do with optical formulae.

When I saw the lens roadmap and the dot at 550mm I guess I assumed that a final decision hadn't been made as to whether it was going to be 500mm or 600mm.

As I said earlier, a 500mm f5.6 with the higher usable ISO on my K5 will do me just fine.

I thought the same thing.

[bilybianca]

I'd love to see the A* 600mm f5.6 upgraded to AF and weathersealed. The 600mm f4 (F and FA) are too heavy IMO and the DOF of the A* f5.6 is very thin, I don't know what to use a thinner DOF for. But within that tiny DOF, it's sharp from wide open. My avatar was shot with this lens (35 mm, not 645) and Fuji colour slide film.
The f5.6 weighs 3 kg, the f4 twice as much. The focal length is just loveable, and in good light the lens can be used with converters. Please keep the sliding hood, it's very convenient!

Kjell

[Vylen]

If this lens is WR with a DC motor, I would love to get my hands on it. Although I dont know what I would do with it

[angus]

When I go for longer walks I usually either carry a 400/5.6 645 ED IF or either the Sigma or the Pentax A* 300/2.8 plus TKs. The 600/5.6 645 is too heavy to carry around for longish periods (>2 hours). I'd welcome something in between though the A* with 1.7 AF converter is already very good and gives me roughly 4.8 open - also heavy though. Hmmmm difficult...

[zapp]

DFA* 550mm F5.4 ED (IF)
MSRP $2999
Weight 2200 g
AF works with 1.4x TC
Speculation, numbers based on model as published in my blog.

does your model cover mirror lenses?
a formula to convert from DA to DFA*?

the basis for a 5.6/600 is a 2.8/300... no 2.8/300 no 5.6/600 no 4.5/500 - what about a 5.5/550 mm mirror lens DA manual focus - big bummer?