Nikon 18-200mm VR

[itsybitsyspidy]

I think having the sharpest lens doesn't automatically make it the best lens except for the sharpness category. Sometimes zoom is more important than the sharpest prime. Sometimes lightweight is more important than wide apperture 80-200mm VR. So choose your favorite subject and buy from there. I don't shoot macro and I don't shoot little birds atop the tree so long sharp lenses are not my thing. I like people and cute pets so a sharp 50-85mm is ideal. I'm not a scenery fanatic so my 18mm is mostly for group photos and in this case, sharp is not as important as long as they can see their faces. So knowing your point of interest can save you money on (1) future upgrade and (b) overspending on features you don't need.

actually for me it's quite alot about the sharpness. i hate it when a picture seems ok on my lcd but when i view it on the computer it's actually not sharp at all. to me i like architecture and portraits, so i guess i need a variety of zooms and wides. but i have to take things slowly, money don't grow on trees. :bsmilie:

 

[lsisaxon]

actually for me it's quite alot about the sharpness. i hate it when a picture seems ok on my lcd but when i view it on the computer it's actually not sharp at all. to me i like architecture and portraits, so i guess i need a variety of zooms and wides. but i have to take things slowly, money don't grow on trees. :bsmilie:

Even the best lenses will look blur when blown up on a monitor. You need to know what is your target output size. My rule of thumb is if the finest detail the lens can give spans more than 2 pixels wide (zoom to 400% and you can see the squares), then there is room for the lens to be sharper. If the finest detail is already within 2 pixels, then you are already limited by sensor resolution.

 

[wiz23]

Even the best lenses will look blur when blown up on a monitor. You need to know what is your target output size. My rule of thumb is if the finest detail the lens can give spans more than 2 pixels wide (zoom to 400% and you can the see squares), then there is room for the lens to be sharper. If the finest detail is already within 2 pixels, then you are already limited by sensor resolution.

Wow :bigeyes: i just learnt something new, thanks

 

[itsybitsyspidy]

Even the best lenses will look blur when blown up on a monitor. You need to know what is your target output size. My rule of thumb is if the finest detail the lens can give spans more than 2 pixels wide (zoom to 400% and you can see the squares), then there is room for the lens to be sharper. If the finest detail is already within 2 pixels, then you are already limited by sensor resolution.

but lets say i take a photo at 3000+ X 2000+ resolution, a good lens would capture everything sharp at 100% right? coz sometimes if some photos are abit blur i tend to sharpen them and reduce image size to improve on the quality. i dont quite get your idea, if i blow an image past 100%, it's sure to pixelate right? so what do you mean by spanning more than 2 pixel at 400% means the photo can be sharper? to test how sharp my lens can get issit to take a photo on a tripod and see how sharp it can get? sorry i'm abit slow on this. please advice. thx. :sweatsm:

 

[dawgbyte77]

Just to clarify... not that I'm assuming you did but for the sake of example, no amount of sharpness can fix out of focus. Also, if you use depth of field as F2.8, say 2 rows of people, you may get blurred image at the front or behind. I believe the sharpness of 18-70mm is better than your average (sometimes even high-end) point & shoot cameras. Another thing is that sometimes I find RAW to be less sharp (my opinion, not scientifically proven) compared to straight JPEG. But then again, I'm wearing spectacles with very thick lenses.

 

[lsisaxon]

but lets say i take a photo at 3000+ X 2000+ resolution, a good lens would capture everything sharp at 100% right? coz sometimes if some photos are abit blur i tend to sharpen them and reduce image size to improve on the quality. i dont quite get your idea, if i blow an image past 100%, it's sure to pixelate right? so what do you mean by spanning more than 2 pixel at 400% means the photo can be sharper? to test how sharp my lens can get issit to take a photo on a tripod and see how sharp it can get? sorry i'm abit slow on this. please advice. thx. :sweatsm:

I think you didn't get what I mean. Yes, I meant a test for lens sharpness.

If a lens is sharp, then if the image falls on the sensor, it can either fall spot on the pixel or it will fall somewhere in between both. So to check that, what you can do is to zoom in until you can see the pixels. If a transition which you are sure is in spot-on focus, on the image, the transition should span no more than 2 pixels. If the lens is not sharp enough, then the transition would step through several pixels before it reaches the other tone.

Here is an examples of what I mean by the transition over less than 2 pixels. The shot is taken with D2X at 12mp and a small region cropped out and blown up.

which is part of this picture

Nikon 105/2.8 Micro

As you can see, the transition of the sharpest details do not span more than 2 pixels. This shows that the images are still limited by the sensor resolution not the lens resolution.

Comparing with this picture, taken with a D70s at 6mp, the Nikon 18-70mm DX cannot even resolve details to within 3 pixels.

which is part of

Nikon 18-70/3.5-4.5 DX

Which would also means that on a D2X, the lens would not be able to resolve to better than 4 pixels.

 

[alechim]

alot of other factors determine the sharpness of a pic, ample lighting do have an impact...

 

[lsisaxon]

Just to clarify... not that I'm assuming you did but for the sake of example, no amount of sharpness can fix out of focus. Also, if you use depth of field as F2.8, say 2 rows of people, you may get blurred image at the front or behind. I believe the sharpness of 18-70mm is better than your average (sometimes even high-end) point & shoot cameras. Another thing is that sometimes I find RAW to be less sharp (my opinion, not scientifically proven) compared to straight JPEG. But then again, I'm wearing spectacles with very thick lenses.

Yes. RAW output is definitely less sharp than the JPG because normally (unless overridden) the camera processor will sharpen the picture before it is converted to JPG.

 

[espn]

Eh? Not the case to my testing of the D2x wor..

Original Image

The rest are all 100% crops

 

[alechim]

Eh? Not the case to my testing of the D2x wor..

What lens did you use sia??

 

[lsisaxon]

Eh? Not the case to my testing of the D2x wor..

Can you do a 300% crop so that you can see the pixels? Which lens is that?

 

[markccm]

for such high MP, holding & breathing techniques are very important as well.

just a little shakes & it shows greatly due to the details captured.
in this aspect, its not very forgiving.

 

[lsisaxon]

for such high MP, holding & breathing techniques are very important as well.

just a little shakes & it shows greatly due to the details captured.
in this aspect, its not very forgiving.

Of course when you want to do a test, use a tripod or use flash.

Same goes for film. I am used to shooting for prints up to 16"x20".

 

[espn]

What lens did you use sia??

I bollow 50 f/1.8 use one...

 

[itsybitsyspidy]

oh lsisaxon bro, i think i'm getting what you mean. i learnt quite abit from your detailed explaination. How sharp my photo can get, provided i use a tripod and have ample lighting, is also dependant on how much detail the camera itself can capture. Thus in the example of D70s(6mp), when you blow up 400% the transition is more than 2 pixel, whereas if you've replaced the body with a DsX(12MP) on the tripod, same lens same shot, you would have ended up with a sharper and more detailed photo right, and blowing to 400% now would only result in a transition of possible just 2 pixel only?

In short, the so called sharpness i have been looking for may not only be limited by the lens itself, but also on the camera body itself?

Lets say the 18-70 on D70s takes about 4 pixels to be able to resolve the details, then on a D2X(theoretically) it should take about 8 pixels to resolve the details?

paisae i so problematic :sweat:

 

[lsisaxon]

oh lsisaxon bro, i think i'm getting what you mean. i learnt quite abit from your detailed explaination. How sharp my photo can get, provided i use a tripod and have ample lighting, is also dependant on how much detail the camera itself can capture. Thus in the example of D70s(6mp), when you blow up 400% the transition is more than 2 pixel, whereas if you've replaced the body with a DsX(12MP) on the tripod, same lens same shot, you would have ended up with a sharper and more detailed photo right, and blowing to 400% now would only result in a transition of possible just 2 pixel only?

In short, the so called sharpness i have been looking for may not only be limited by the lens itself, but also on the camera body itself?

Lets say the 18-70 on D70s takes about 4 pixels to be able to resolve the details, then on a D2X(theoretically) it should take about 8 pixels to resolve the details?

paisae i so problematic :sweat:

You're getting close. Except that in your last remark, if a lens can resolve to 4pix on a D70, on a D2X it does not take 8pix but rather 1.4 (square root of 2 since the megapixels is doubled) x 4 which is near 6 pixels.

So you see, even when the megapixel number is doubled the linear resolution improves only by about 1.4x.

Ultimately, even if you have the best lens, if you blow the image to 100% pixel size, you will still see that it is blur. Only when you define the output size to a fixed physical size will you se an improvement because now over the same area, you have more pixels to represent the picture.

 

[itsybitsyspidy]

You're getting close. Except that in your last remark, if a lens can resolve to 4pix on a D70, on a D2X it does not take 8pix but rather 1.4 (square root of 2 since the megapixels is doubled) x 4 which is near 6 pixels.

So you see, even when the megapixel number is doubled the linear resolution improves only by about 1.4x.

Ultimately, even if you have the best lens, if you blow the image to 100% pixel size, you will still see that it is blur. Only when you define the output size to a fixed physical size will you se an improvement because now over the same area, you have more pixels to represent the picture.

wow thx bro, i think i've finally understood what you meant. thanks for all the trouble.

 

[itsybitsyspidy]

Anyone has any inside information on when there will be new stock for this lens? I'm going crazy waiting for it. :angry: ahhhhhhhhhhhhhhh!! :mad2:

 

[Andy Ang]

Not good enough, ditch the 18-70 for 17-35 at least.

Sounds good.. :devil:

Sell me the 18-70 ba... ;p

 

[espn]

Sounds good.. :devil:

Sell me the 18-70 ba... ;p

:nono: You also buy 17-35.. go go go!!