[dafiryde]

had a recent conversation on lenses
can you tell me how much of this is true
for someone who takes pictures and only reviews them on a computer screen and never prints them,
you will see very little difference between cheap lenses as compared to expensive lenses

Dave

[bymy141]

had a recent conversation on lenses
can you tell me how much of this is true
for someone who takes pictures and only reviews them on a computer screen and never prints them,
you will see very little difference between cheap lenses as compared to expensive lenses

Dave

Absolute nonesense. I would argue for the opposite.
Screens are in general much larger than prints made.
Also people do make crops of the pictures, so enough resolution is good as well.
On screens (17" - 22" or even larger) you will notice purple fringing, vignetting and out of focus problems more than on a 10x15 cm printed photo.

- Bert

[silent_eyes]

had a recent conversation on lenses
can you tell me how much of this is true
for someone who takes pictures and only reviews them on a computer screen and never prints them,
you will see very little difference between cheap lenses as compared to expensive lenses

Dave

actually, it's the other way around... you'll see most of the differences while pixel-peeping, on paper it's a lot harder to notice anything really that detail. Ofcourse, I'm not including here objective elements like DoF or direct light contrast, but overall look such as sharpness and tiny amounts of purple fringing...
I've printed a lot of shots(30x20cm and 45x30cm) with my k10d+18-55 and it's way more that acceptable, but when I look at 'em on my cheap LCD display, I wish more, and compared to 50-135 - it's no contest at all... quality is more than obvious. Now, I used PentaxME+Braun 28-70 3,4-4,8 lens for a while, and it gave great results enlarged to 30x20cm or 24x18cm, but - I can tell the difference when compared to Takumar 35-70 f/3,5 prints... Tak is just better, and you can tell it even on paper...
so, is the cheap lens something you should disregard? Not a chance
After all, if the shot is good, who cares how sharp is it, or which brand of butter is that "smooth-butter" look of DoF...

[Frank Fletcher]

After all, if the shot is good, who cares how sharp is it, or which brand of butter is that "smooth-butter" look of DoF...

Yes - that's why I do all my commercial shots on a pinhole....

[Ex Finn.]

had a recent conversation on lenses
can you tell me how much of this is true
for someone who takes pictures and only reviews them on a computer screen and never prints them,
you will see very little difference between cheap lenses as compared to expensive lenses

Dave

Not true at all, as long as your monitor is not completely shot or misadjusted.

Cheers.
Mike.

[Marc Sabatella]

for someone who takes pictures and only reviews them on a computer screen and never prints them,
you will see very little difference between cheap lenses as compared to expensive lenses

As other posters have indicated, the screen is *capable* of showing you much more than a print would. But if you only view them big enough to fill the screen, then the differences won't be nearly as noticeable as if you blow them up to "full size", where the screen shows only a small part of the whole picture at once. Even though most screens are physically larger than a 4x6 print, they may not actually contain as many pixels. So depending on exactly what kind of defects you are looking for, it might not be as easy to see them until you blow them up to full size.

But then, sometimes the difference between cheap lens and an expensive is obvious long before you get that far. I've got a 200mm lens with a maximum aperture of f/4. One with a maximum aperture of 2.8 costs *much* more. The difference in maximum aperture may make all the difference in the world in terms of whether you can get a fast enough shutter speed to stop the action, or even to stop camera shake. And it will also have a pretty *obvious* effect on DOF.

Similarly, I've got a cheap 50mm lens that won't let me focus closer than a few feet. I would have to pay much more for one that let me focus a few inches away. The latter lens would let me take closeups I could never take with my lens.

[dafiryde]

thanks for your input
the reason this conversation started was when i got my k10d i bought the 16-50 2.8 lens and was happy, then i wanted more reach, so i went and bought the 50-135 2.8 lens and was happy
but recently i find my self loosing the shot i want, cause i have to change the lens and by that time the shot i wanted is gone
so i was looking at the 18-250 lens and wondered

Dave

[konraDarnok]

will see very little difference between cheap lenses as compared to expensive lenses

Dave

How cheap?

Generally speaking, no. There are lenses that have a reputation of being bad. Avoid those. But many many *inexpensive* lenses can produce very fine images.


*expensive* generally means Fast.


And besides that. . . you either take interesting photos, or you don't.

Nobody looks at photos for technical reasons. They want to see something they've never seen before.. . . not how many test chart lines a lens can resolve.

[Wheatfield]

had a recent conversation on lenses
can you tell me how much of this is true
for someone who takes pictures and only reviews them on a computer screen and never prints them,
you will see very little difference between cheap lenses as compared to expensive lenses

Dave

Nope. A better lens is a better lens, and will give a better result, all else being equal, no matter the viewing medium.
The tendency to blow things up to ginormous magnifications on screen and then stick our noses a foot away from the monitor will show up all sorts of lens nasties that wouldn't otherwise be visible on a reasonable sized print viewed at a normal distance.
A K20 image at 100% on a monitor would be some 43x64 inches were it a print, presuming a 72dpi monitor resolution.

[Class A]

so i was looking at the 18-250 lens and wondered

This lens isn't as fast as the ones you've got. It also has relatively high barrel distortion at 18mm. Unless stopped down, there can also be some vignetting at the wide end.

Having said that, with your body shake reduction, the lens should work for you well in most light situations. I've never had any auto-focusing problems on a K100D with it either.

Vignetting hasn't been a problem for me either in practice. Just don't shoot a clear sky wide open with 18mm. The lens can create very, very sharp images, if stopped down a bit.

And the Macro facility is a great bonus, AFAIC.

I can fully recommend the lens for its versatility and image quality (my copy is perfectly centred). You'll find a lot of praise for it on the web. Just beware that, as a super zoom, it inherently has the above mentioned limitations which can easily be avoided by stopping down (vignetting) and/or corrected by software (barrel distortion at the very wide end). Unless you shot a brick wall or intend to capture architecture accurately, the barrel distortion will typically go unnoticed anyhow.

[Marc Sabatella]

I can fully recommend the lens for its versatility and image quality (my copy is perfectly centred). You'll find a lot of praise for it on the web. Just beware that, as a super zoom, it inherently has the above mentioned limitations which can easily be avoided

Except for speed, of course - no way to get around the lack of f/2.8.

[dafiryde]

And besides that. . . you either take interesting photos, or you don't.

Nobody looks at photos for technical reasons. They want to see something they've never seen before.. . . not how many test chart lines a lens can resolve.[/QUOTE]

That is a food for thought, well said

can you say if between the kit lens and the 18-250
should i expect same , worse or better quality

Dave

[Marc Sabatella]

can you say if between the kit lens and the 18-250
should i expect same , worse or better quality

Roughly the same. 18-250 will probably be a bit better near 55, 18-55 a bot better near 18. But we're talking relatively small differences here compared to the difference between either of these and the DA* zooms or a decent prime.