18-135mm DA WR

Not again David, out of the 7 SDM lenses, 2 had a bad start and the other 5 never had a problem.

The most likely not to use the DC is if the DC is a Brushless DC motor is not powerful enough to move the heavier lens elements of the DA* lenses and the sealing, Ultrasonics engines are know to have a very high-torque for their size.

While at home playing with my 18-135 last night I noticed that it turned my TV screen into a deep curved cinema screen on the longer settings. The pin-cushion distortion is present at all focal lengths but only gets really obvious from about 40mm upwards.

(Observations from looking through the viewfinder only over relatively short distances).

Perhaps I can ask you to make allowances for a digital beginner. I have just upgraded from six M lenses and an A to a set of five DA lenses and a K5. I was not aware of the miracle of 'Lens correction'. The pin cushion distortion has pretty much disappeared. Not in the viewfinder of course.

That lens correction is amazing.

It's cheating though and degrade the IQ, I don't like it

Ah - back to the DC brushless motor.

Another name for them is heaters.

I don't agree that anything in digital photography is cheating - to cheat you have to deliberately break rules for your advantage. Not sure that applies at all.

As regards a loss in quality, if there is one I can't spot it with images side by side on screen at 100%.

Not sure how this may relate to the UK/USA but over here (SHanghai) the K5 + 18-135 costs £1,200 (£900 for K5 alone) so that is of course £300 for the lense.

Put me down for 3

*sees a business opportunity*

Why do you think I want 3.

Sell 2 at £450 each, mine would be free .. sorted

Oh I forgot, that sort of thing is frowned on by some ...

Just looking at the prices quoted over here for The K5 kit + 18-135mm
AU$2229 (£1370), Body only AU$1620 (£1000), Lens only AU$600 (£370)

It's still not available at my local camera store, Early December I am told. It's significantly more expensive than the K7 when it was first released. I will hang off for a while and see what happens.

I recall when the K7 was released, we were paying about £740 compared to you guys paying in excess of £1000, but that was before the bottom fell out of the pommy pound

I haven't said everything digital is cheating but they are basically covering up a defect off a lens. It's useful though the correction but I rather have it that they make a good lens without the distortion then use software to correct it.
In such a way i find it cheating, i hope it doesn't make the lens designers lazy.

The quality lost is with the stretching of the pixels.
Without correction they are nicely square so to say but because of the correction the pixels get stretch out so there surely is some quality lost in there. It's a bit like upscaling a photo the effect.
The best way to see the differnce is to shoot one with a lens that doesn't need correction and compare it with a lens that does need correction.
You will see the in the distorted part will be a less detial in the corrected shot.
There is no real lost in quality because the quality stays the same of the photo, it's that one pixel on the sensor is now displayed on two pixels on the screen so it can not capture the details of an lens that doesn't need correction.
Basically you are lowering the amount of pixels with the correction.

Does that make sense?

The comment about manufacturers deciding to correct lenses in camera rather than in design hasn't really happened yet, but in time it could do. It would be even more clever to push inmdependent manufacturers out by keeping the correction ability strictly for marque lenses only, thus making them cheaper to make and more competitive. However, theres no current evidence that this is the intention. The thing that universally is allowed to drift is the distortion level and the cameras can now help in this respect.

The second point doesn't hold up as there is no apparent deterioration. I have looked, very, very closely and there is no detrimental effect aprt from the processing time. For architecture this will be very useful

Comparing with another lens isn't a valid comparison because it's a different lens.

This would appear to be a total contradiction.

I hope it stays that way.
Many compacts now a days have the correction standard i wonder if some "laziness" have slip in there. Maybe it's not really laziness but more a money question.

But there is no other way, how else can you compare what the differnce in quality is with digital distortions correction?

I said it a bit wrong at first but there is no lost in quality by the correction because it spread the pixel/quality out to correct the distortion.
What i mean is that if you compare the corrected part of "optical" corrected lens (so to say) and compare the same with but then digital corrected there will be a differnce in the smaller details captured.
Digital correction lowers the amount of pixels in the corrected part.
Of course the lens must be good enough to use the pixel effectively to begin with.

I know i make it sound very confusing

Lets make it simpler.
If you stretch a 10mp photo 2 times as wide, it will result in a 20mp photo but it will have the details of a 10mp image since that's the original and you can't add details in post processing since you've no information about the details but because the 20mp holds the same information as the 10mp there is no actual lost of quality.
This basically what happen with digital correction but it's stretch differently.

If you can make the same panorama with out the need to stretch you will only gain in quality right? This what on lens would be that is distortion free.

I hope that makes the point clearer that i'm trying to make.