This is what we should expect. Wide angle (relatively) lenses that take their light from a wider field need larger front elements to gather that light evenly. That's a sort of botched explabnation, but think how much the relatively long barrel of the lens will shade that light compared to at the telephoto end where there is a straight view right gown the lens barrel. So to speak.

Not a problem, but please remember that we know that the Pentax 18-55mm wide open is fairly soft and that the picture changes dramatically by f8.

If you really wanted to see what the comparison is between lenses then I do have prints, but I'm not sure where you are located, so offering to meet and discuss may not be an option.

I'm tempted to suggest that we have a lens meeting at the ADAPS clubroom in Atherton, Manchester. There were no takers when we tried a PU event with model and presentations all day, but I could do an evening meeting with perhaps and hour presentation followed by discussion.

We would have to put something into the club funds to cover use of the rooms, but my time would be the right price - free.

Does anybody think this would be a good idea?

OK, not the easisest of tasks, but I'll have a go.

There's a problem with the point of focus because I'm not convinced that it's in the same place for the two shots, but have a look at the "hairs" top right against the blue background. Also look at the reproduction of the catchlight in the eye. Look at the sharpness of the detail just beyond the eye.

Although neither lens shows any more information than the other, the right hand picture reproduces it with slightly more crispness. I am assuming that this is not because the contrast has been tweaked, but just taking it at face value that both images are unretouched.

It's not conclusive because the resolution of our screens is not sufficient and also our monitors probably differ anyway.

"Quality" is also a subjective term, but I mean it as a summing up of sharpness, resolution, bokeh, contrast and all the other optical properties into a summation that is pleasing to the eye.

There is a difference though in the images, and it is marked at wide open aperture or near to wide open aperture but becomes more difficult to spot at smaller apertures.

When I did similar tests I used maps to photograph - lots of fine detail - and I made my conclusions from A3 prints. The results were interesting but they did fall into line with expectation. But stopped down, the differnce between the 18-55mm and 16-45mm lenses was not appreciated by many viewers, and they certainly would not have paid the extra for the better lens. Had they bought it after taking quite correct advice they would have been very disappointed that nothing miraculous happened to their photography.

Lens testing like this is just intersting vut not conclusive, but the real test os whether or not our lenses produce images that fulfill our expectations.

What I see in the images in front of me.

What I perceive as a slightly lower degree of quality that would be magnified somewhat by the time it became an A3 print, which would be my requirement for a lens.

What do you see?

At f8 all the lenses are much harder to tell apart, at screen resolution anyway.

The test tells me that the 18-55mm performs very well when stopped down. Also that the 50mm, as expected, works well at two stops down and even better when stopped down to f8.

The new DA* is not exceptional in this test but the worst of the lenses is probably the 18-200mm.

In order of sharpness: 4 2 1 3

It will be interesting to know which lens is which, but it only gives part of the picture. At f8 the results could be entirely different, so if you shot lots of landcscapes at f8 it would make this test of limited value.

However, it's an interesting exercise.

So which lens is which?

I've tried this before with a similar lack of success.

It makes you wonder whether there is any stock in existence. If there is no stock, any price you like could be advertised.

There was availablity at £49.99 at Jacobs until relatively recently.

Try the Jessops clearance stores - the price there has been around £107.00

I will, thanks.

My photochromic glasses turned instantly black.....