[Martin_Qc]

Hello all.

I've been looking around the internet without finding the exact answer I'm looking for. So, here's my questioning :

I have a DA* 50-135mm in my bag. LOVE it, great lens, but with the use I have for the camera as we speak, I need something with a bigger reach.

Is it possible to find a telephoto lens, f2.8 with a range from something around 100 to 300mm with a BIG glass, 70mm diameter and up that fits a Pentax ?? Not an obligation to be a Pentax product, I'm fine going with a Sigma or other maker.

The only answers I get from my search are primes at 200 or 300mm. They are nice (very nice) but I'd prefer something with a zoom, more versatile for my needs.

I'm I deaming of a utopia here or is it something I could find ?

I'm asking you guys now, Pentax gurus because my searches came back almost empty.

Thanks for the help anyone can provide.

[Adam]

There's a Sigma 70-200mm (no longer in production) and Tamron 70-200mm (still in production). Both are very good optically. Note that there are several variants of the Sigma, so refer to our lens database:

Pentax Lenses by Sigma, Tamron, Zeiss, and more - Reviews and Specification Database - Pentax Lens Review Database

Sigma also makes a 120-300mm F2.8, but it isn't available for Pentax (and commands a $3599 price tag).

[SpecialK]

There is this:

Sigma APO 200-500 f/2.8/400-1000 f/5.6 Lens f/Canon 597101

However, if $25,999 is a bit over your budget, you could downsize to this:

http://www.adorama.com/SG120300NCAK.html?adver=new&

Of course you would need a new body to stick on it.

[johndny]

If you have an unlimited budget, it might be possible to buy a Sigma 120-300mm f2.8 in Canon/Nikon mount and then have Sigma convert it to Pentax mount. (The "downsized" lens SpecialK and Adam mentioned above.)
You would have to talk to a Sigma representative to see if this is possible, however, as the lens is not offered in Pentax K-mount to begin with.

Lens: SIGMA 120-300mm F2.8 DG OS HSM | Sport - Telephoto Zoom Lenses - SigmaPhoto.com ($3600 on Amazon.... Yikes!)
Mount conversion: Change Your Mind? Change Your Mount. Sigma Corporation of America (another $250 + shipping)

Edit: was looking through the info on the Sigma mount conversion and came across this: "*Subject to mount, parts and service availability. Not all products are available in Pentax and/or Sony Mounts. Please check the specific product page to check availability in those mounts." So, you probably could not do the conversion (still wouldn't hurt to check with a Sigma representative if it's in your budget - it's definitely not in mine).

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Last edited by johndny; 02-23-2015 at 09:10 PM.

[johndny]

Also if manual focus is acceptable, you could consider buying a Pentax Q series camera (~$200) and K-mount adapter (~$200), and enjoy the resulting 5.5x focal length multiplier on your existing 50-135 (3.7x compared to Pentax DSLRs --> the 50-135 on the Q would be equivalent to a manual focus 183-495mm f2.8 on your DSLR).
Sensor quality would probably suffer (significantly?) compared to your current camera, however.
https://www.pentaxforums.com/reviews/pentax-k-mount-to-q-adapter/telephoto-tests.html
Food for thought.

[Prakticant]

BTW: Does DA* 50-135mm/2.8 work with Pentax 1.4x (2.0x) teleconverter? Would be great for travel

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I have a DA* 50-135mm in my bag. LOVE it, great lens, but with the use I have for the camera as we speak, I need something with a bigger reach.

[Adam]

You would have to talk to a Sigma representative to see if this is possible, however, as the lens is not offered in Pentax K-mount to begin with.

The mount conversion service is only available for mounts that the lens is normally produced in

BTW: Does DA* 50-135mm/2.8 work with Pentax 1.4x (2.0x) teleconverter? Would be great for travel

Yes, it most certainly does, but you may as well get the DA* 60-250mm F4 IMO. It's a stop slower by default, but man is it a sharp lens!

Adam
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[DSims]

f/2.8 already makes for a very large lens on a 300mm prime. With a zoom it will be even larger! And all 300mm f/2.8 lenses will generally cost $3000 or more.

In general you're better off getting a *300 lens (f/4 or f/4.5) and a 2nd body - especially if you're still using an older body that can be had pretty cheaply. I realize carrying 2 bodies could be considered cumbersome for some people, but I think carrying 1 body with a lens as large as you're describing would be even more cumbersome.


Also, all of the AF *300 lenses (F, FA, DA) have especially good IQ that compliments your DA*50-135. Any other solutions we can come up with (including the DA*60-250) will compromise that IQ a bit. So you'll have to decide what your priorities are. What type of subjects are you shooting?

[Jack Simpson]

You could, Martin, pick up a Q7 along with a K to Q mount adapter and pop your DA50-135/2.8
on it . That would give you a 275 - 742.5/2.8 lens, albeit manual focus.

Cheers,

Jack