70-200 or 70-300 for Pentax

Can anybody recommend a 70-200 or 70-300 lens for a Pentax K20D? Should
be sharp enough for a 14MP APS-C sensor. Doesn't have to be F2.8,
because of weight & bulk & cost - an F4 lens would suffice, provided
it's sharp enough. I know that the Pentax 50-135 F2.8 is good, but would
prefer a longer lens.
--

Alfred Molon
------------------------------
Olympus 50X0, 8080, E3X0, E4X0, E5X0 and E3 forum at
http://tech.groups.yahoo.com/group/MyOlympus/
http://myolympus.org/ photo sharing site

Alfred Molon wrote:
Can anybody recommend a 70-200 or 70-300 lens for a Pentax K20D?
Should be sharp enough for a 14MP APS-C sensor. Doesn't have to be
F2.8, because of weight & bulk & cost - an F4 lens would suffice,
provided it's sharp enough. I know that the Pentax 50-135 F2.8 is
good, but would prefer a longer lens.

Alfred,

If you had bought Nikon, there's a very well respected 70-300mm VR lens:

http://www.europe-nikon.com/product/.../overview.html

David

David J Taylor wrote:
Alfred Molon wrote:
Can anybody recommend a 70-200 or 70-300 lens for a Pentax K20D?
Should be sharp enough for a 14MP APS-C sensor. Doesn't have to be
F2.8, because of weight & bulk & cost - an F4 lens would suffice,
provided it's sharp enough. I know that the Pentax 50-135 F2.8 is
good, but would prefer a longer lens.

Alfred,

If you had bought Nikon, there's a very well respected 70-300mm VR lens:

http://www.europe-nikon.com/product/.../overview.html

David



Wow, that's a very helpful response.

John.

In article , David J
Taylor says...

If you had bought Nikon, there's a very well respected 70-300mm VR lens:

http://www.europe-nikon.com/product/.../overview.html

I haven't bought anything yet, but am not considering a Nikon for the
moment because they don't have a 14MP model and I don't want to change
the camera after a year or two just because the MP count has increased.
With a 14MP model I can skip one generation and upgrade when 16-18MP
cameras hit the market.

And please don't tell me I don't need the MP. Alamy is requesting
submissions with at least 16.7MP and 14MP is closer to that than 10 or
12MP.
--

Alfred Molon
------------------------------
Olympus 50X0, 8080, E3X0, E4X0, E5X0 and E3 forum at
http://tech.groups.yahoo.com/group/MyOlympus/
http://myolympus.org/ photo sharing site

Alfred Molon wrote:
In article , David J
Taylor says...

If you had bought Nikon, there's a very well respected 70-300mm VR lens:

http://www.europe-nikon.com/product/.../overview.html

I haven't bought anything yet, but am not considering a Nikon for the
moment because they don't have a 14MP model and I don't want to change
the camera after a year or two just because the MP count has increased.
With a 14MP model I can skip one generation and upgrade when 16-18MP
cameras hit the market.

Why not go straight to a 25MP camera?

And please don't tell me I don't need the MP. Alamy is requesting
submissions with at least 16.7MP and 14MP is closer to that than 10 or
12MP.

No, they ask for images of at least 17MB, not 17MP.

Big difference.

--
Ray Fischer

Alfred Molon wrote:
In article , David J
Taylor says...

If you had bought Nikon, there's a very well respected 70-300mm VR lens:

http://www.europe-nikon.com/product/.../overview.html

I haven't bought anything yet, but am not considering a Nikon for the
moment because they don't have a 14MP model and I don't want to change
the camera after a year or two just because the MP count has increased.
With a 14MP model I can skip one generation and upgrade when 16-18MP
cameras hit the market.

And please don't tell me I don't need the MP. Alamy is requesting
submissions with at least 16.7MP and 14MP is closer to that than 10 or
12MP.

That seems odd, so I checked the Alamy web site. Under "preparing your
images" and "digital cameras" I found this:

"Use a pro-level camera with a true (non-interpolated) resolution of
at least 6 megapixels. This will give a file size of at least 17MB at
8 bit."

That 17MB refers to file size of something like a TIFF, not camera
MP. Elsewhere on their web site they explain that they expect you to
upsample your submissions to reach the high pixel density they require
on their standardised submissions, specifically recommending Genuine
Fractals as doing the best job.

They expect a 6MP pro camera with a good lens will be good enough.

Which was as I remembered from the last time I checked them out. A
Sony R1 such as you and I have is more than good enough for Alamy
submissions.

--
Chris Malcolm DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
[http://www.dai.ed.ac.uk/homes/cam/]

In article , Ray Fischer
says...
Alfred Molon wrote:
In article , David J
Taylor says...

If you had bought Nikon, there's a very well respected 70-300mm VR lens:

http://www.europe-nikon.com/product/.../overview.html

I haven't bought anything yet, but am not considering a Nikon for the
moment because they don't have a 14MP model and I don't want to change
the camera after a year or two just because the MP count has increased.
With a 14MP model I can skip one generation and upgrade when 16-18MP
cameras hit the market.

Why not go straight to a 25MP camera?

Not available yet, besides will likely be way above my budget.

And please don't tell me I don't need the MP. Alamy is requesting
submissions with at least 16.7MP and 14MP is closer to that than 10 or
12MP.

No, they ask for images of at least 17MB, not 17MP.

Big difference.

Nope. They ask for 48 MByte images, which translates into 16.7 MP.
--

Alfred Molon
------------------------------
Olympus 50X0, 8080, E3X0, E4X0, E5X0 and E3 forum at
http://tech.groups.yahoo.com/group/MyOlympus/
http://myolympus.org/ photo sharing site

John wrote:
David J Taylor wrote:
Alfred Molon wrote:
Can anybody recommend a 70-200 or 70-300 lens for a Pentax K20D?
Should be sharp enough for a 14MP APS-C sensor. Doesn't have to be
F2.8, because of weight & bulk & cost - an F4 lens would suffice,
provided it's sharp enough. I know that the Pentax 50-135 F2.8 is
good, but would prefer a longer lens.

Alfred,

If you had bought Nikon, there's a very well respected 70-300mm VR
lens:
http://www.europe-nikon.com/product/.../overview.html

David



Wow, that's a very helpful response.

John.

It was intended to show there is more to choosing a camera than just the
MP count. You need to look at the complete system.

David

Alfred Molon wrote:
In article , David J
Taylor says...

If you had bought Nikon, there's a very well respected 70-300mm VR
lens:


http://www.europe-nikon.com/product/.../overview.html

I haven't bought anything yet, but am not considering a Nikon for the
moment because they don't have a 14MP model and I don't want to change
the camera after a year or two just because the MP count has
increased. With a 14MP model I can skip one generation and upgrade
when 16-18MP cameras hit the market.

And please don't tell me I don't need the MP. Alamy is requesting
submissions with at least 16.7MP and 14MP is closer to that than 10 or
12MP.

More MP equals more noise. Are you really sure you want that?

Others have already mentioned that 6MP is enough to Alamy.

Cheers,
David

Thanks for your reply, but that still doesn't answer my question ahout
the 70-300 lens.

Sigma and Tamron have such lenses, but performance is less than stellar.
Sony seems to have a good 70-300 lens, which makes me wonder if I should
get a A350 instead.
--

Alfred Molon
------------------------------
Olympus 50X0, 8080, E3X0, E4X0, E5X0 and E3 forum at
http://tech.groups.yahoo.com/group/MyOlympus/
http://myolympus.org/ photo sharing site