[johnmflores]

~ 224 mm/f16 equiv. for FF.

FA77/1.8 ~ 430 mm/f10

FA50/1.4 ~ 280 mm/f8


hard to say that such adapter has any serious sense. just for fun IMO.

Paper thin DOF is not the Holy Grail of photography.

[eddie1960]

Paper thin DOF is not the Holy Grail of photography.

tell that to the people on all the Full Frame threads. it's the number one argument for FF (erroneously if you ask me; there are better reasons for FF)

[Blue]

tell that to the people on all the Full Frame threads. it's the number one argument for FF (erroneously if you ask me; there are better reasons for FF)

Not really. It gets kicked around. I would say one of the main arguments has more to do with the actual size of the sensor relative to the fov which favors the wide angle lenses more than aps-c does.

[ghelary]

~ 224 mm/f16 equiv. for FF.

FA77/1.8 ~ 430 mm/f10

FA50/1.4 ~ 280 mm/f8


hard to say that such adapter has any serious sense. just for fun IMO.

Nice trolling attempt. Now please learn what F-stop means.

[devorama]

Someone has some real world photos from the Q at full res. Some are ISO 1600 and 1250.

http://www.yaotomi.co.jp/blog/used/2011/08/pentax-q-2.html

[Christine Tham]

Someone has some real world photos from the Q at full res. Some are ISO 1600 and 1250.

http://www.yaotomi.co.jp/blog/used/2011/08/pentax-q-2.html

Wow!

Impressive!

Wonder if these images have been post-processed.

There are a few hot spots (red pixels) in the long exposures, which suggest they haven't been extensively noise reduced.

Judging by the blog entry, the poster said the images were uploaded straight after shooting, so probably not post processed. The poster also promised to take more photos in daylight.

[deadwolfbones]

Pentax 1000mm f/8 on the Q.

[ogl]

Nice trolling attempt. Now please learn what F-stop means.

Learn yourself

[falconeye]

~ 224 mm/f16 equiv. for FF.

FA77/1.8 ~ 430 mm/f10

FA50/1.4 ~ 280 mm/f8


hard to say that such adapter has any serious sense. just for fun IMO.

Actually, I personally consider the tele converter effect to be the most interesting option offered by the Q.

We don't need to consider the crop factor. The difference in pixel pitch is what is of concern here.

Pentax K-5: 4.75 µm
Pentax Q: 1.55 µm

"Pitch-Factor" Q/K-5 = 3.06 (~3)

(the difference in crop factor is a bit larger, like 3.75.)

This means that a DA*300 on the Q could resolve (in theory) like a 900mm lens on a K-5.

A DA*300 has best resolution (and it needs its absolute best to make any sense on the Q) around f/4.7. At f/4.7, the diffraction disk (Airy) radius is 3.15 µm meaning its diffraction-limited resolution (pixel distance) would be 1.58 µm. That would be on the edge of things and pixel contrast of a DA*300 on a Q would be small. But not zero if its optical construction permits.

In practical terms, I'd say a DA*300 may resolve like a 500-600mm lens on a Q.

Still good enough and not useless.


BTW,
it's not uncommon to mount small pixel pitch cameras onto large tele lenses. It is the standard technique when doing planet photography, where a webcam is the small pixel pitch camera and a mirror scope is the large tele lense. To improve image quality, stacking a couple hundred images is another standard technique then (as this allows to boots the contrast up to the exact diffraction limit and compensates for air turbulence and tracking issues).

[aurele]

Pentax 1000mm f/8 on the Q.

i did'nt realize what you were showing.

A 1000mm f8 on the Q gives such a huge zoom effect

it's incredible !!

A nice body for birding and no more need for Canon ultra expensive and long lenses

[ogl]

This means that a DA*300 on the Q could resolve (in theory) like a 900mm lens on a K-5.

A DA*300 has best resolution (and it needs its absolute best to make any sense on the Q) around f/4.7. At f/4.7, the diffraction disk (Airy) radius is 3.15 µm meaning its diffraction-limited resolution (pixel distance) would be 1.58 µm. That would be on the edge of things and pixel contrast of a DA*300 on a Q would be small. But not zero if its optical construction permits.

In practical terms, I'd say a DA*300 may resolve like a 500-600mm lens on a Q.

Still good enough and not useless.
.

Like 900 mm or like 600 mm? Only at f4.5?

It's rather strange way to get picture with 600 (900) mm lens resolution:
To buy Pentax Q for USD800 + Q-K adapter for some USD (I think USD200) and then buy DA*300/4 for USD1300....
Wow...it's outstanding. To spend more than USD2000 for make some shots at 1680 mm (without AF!!!) at f4.5 in very good sunny weather at ISO125 with exposure limit 1/2000 .


Don't forget about ISO and exposure (1/2000 only), please. I doubt that It will give any good IQ at ISO above 200.

[ogl]

Pentax 1000mm f/8 on the Q.

Show me, please, the photos from this combo - 1000 mm needs 1/6000. Pentax Q can only 1/2000.

[falconeye]

It's rather strange way to get picture with 600 (900) mm lens resolution:
To buy Pentax Q for USD800 + Q-K adapter for some USD (I think USD200) and then buy DA*300/4 for USD1300....

Think about it again.

Many already have a DA*300, the Q will drop to $250 (at least, DxO sees them there) and the parameters you quote aren't that unrealistic.

Say, we speak about a lens which would be equivalent to an APSC lens of 600mm f/8, shot at f/9 - f/10 (it may indeed be too hard to exploit the 900mm reach). The Q has SR, so 1/500s may be fast enough (assuming the focal can be dialed in). The ISO noise is that what would result from f/10 at 1/500s on APSC. E.g., for EV 14.5, you'll only need ISO 200. Which is noiseless. On the Q, you'll actually already use base ISO then.

So, that's perfectly making sense.


I agree, a 600mm f/8 $1000 K-mount lens with ~8 elements and ED glass is the preferred option (*). It just doesn't exist. So, don't neglect an option the Q gives you.

__
(*) As I write in my blog, I actually recommend Pentax to do a 500mm f/5.6 $2000 lens ( -> Falk Lumo: A hypothetical Pentax DFA* 500mm F5.6 ED(IF) SDMii )

[ogl]

Think about it again.

Many already have a DA*300, the Q will drop to $250 (at least, DxO sees them there)

OK. Good joke...

[falconeye]

OK. Good joke...

Joke?
Then look it up here -> DxOMark - Pentax Q

Personally, I'd give it a $350,-

It either drops to this price after first enthusiasts have purchased their box, or Pentax sees it as a limited edition experiment with samples soon being sold out.

In any case, if the price doesn't drop below $400 then there is no reason to discuss the Q at all: because then there are only so few samples out there.

Therefore, if I invest my time to discuss the Q, it is only logical to assume a price which makes sense.


And if you argue the Q is allowed to be more expensive than another good 1/2.3" P&S -- just because it is a system camera with a mount -- then I'd reply that my Phillips ToUcam Pro II has a mount and wasn't more expensive than other webcams.