testing a lens for sharpness

clive

clive

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clive
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how do i find out just how sharp a new lens is ie do i switch in camera sharpening off and shoot in raw/tripod mount just wondered what the best way is to do it before i go playing with my new toy its a tokina 11mm-16mm f2.8 btw.
 
Just take pictures with it, why you want to concern yourself over such things before you use it beats me :shrug:
 
If you go looking for problems, you'll find them. And unless you have a very good idea of what is good for a lens of that type, and what is less good, you'll be disappointed. When in reality, it's a known high quality lens.

Whatever you do, don't check sharpness in the corners at 11mm f/2.8 :eek: :D
 
u8myufo said:
Just take pictures with it, why you want to concern yourself over such things before you use it beats me :shrug:
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+1

Sharpness is over-rated. Stop worrying. Go take some interesting photographs. And if they're sharp count that as a bonus (unless the sharpness is distracting from the interstingness).

But please don't share them if they're not interesting (regardless of sharpness) :thumbs:

Noone has yet taken an interesting photograph of a sharpness/focus test card. You could view that as a challenge, or you could just accept that many excellent photographers have tried and failed in this regard already, and that it's perhaps better to move on to real world subjects.. .. ..
 
Alastair said:
Noone has yet taken an interesting photograph of a sharpness/focus test card. You could view that as a challenge, or you could just accept that many excellent photographers have tried and failed in this regard already, and that it's perhaps better to move on to real world subjects.. .. ..
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:lol: Love it!:lol:
But actually very true.
Go out, take real pictures of real things.
Don't pixel peep, it will drive you crazy.
Enjoy your new lens.
 
u8myufo said:
Just take pictures with it, why you want to concern yourself over such things before you use it beats me :shrug:
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Why? Because most lenses today have to deal with high pixels counts thus may not be upto the job as they date from the film era. Sharpness also lets you know how useable the lens is and wither or not the lens is built correctly.


As or the OPs question take pictures as you normally do and view them at the resolution you normally view them at.
 
POAH said:
Why? Because most lenses today have to deal with high pixels counts thus may not be upto the job as they date from the film era. Sharpness also lets you know how useable the lens is and wither or not the lens is built correctly.


As or the OPs question take pictures as you normally do and view them at the resolution you normally view them at.
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The overwhelming majority of lenses are fine. If you draw the short straw, you have redress under the Sale of Goods Act.

Do you try to find out if your new car can actually do 0-60 in 6.7 seconds before you buy it? Do you use calibrated timing gear to check before you buy?

Well then.
 
jon ryan said:
The overwhelming majority of lenses are fine. If you draw the short straw, you have redress under the Sale of Goods Act.

Do you try to find out if your new car can actually do 0-60 in 6.7 seconds before you buy it? Do you use calibrated timing gear to check before you buy?

Well then.
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And how do you see if your lens is not fine ;)

if most lenses are fine why do you get mk2 versions ;)
 
POAH said:
And how do you see if your lens is not fine ;)

if most lenses are fine why do you get mk2 versions ;)
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It's called "development". What happens is, someone makes something to, picking an example at random, create images of scenes. Let's call the original innovator, to pick a name entirely at random, Joseph Nicéphore Niépce. Joe used a medium called bitumen of Judea on which to record an image of his garden. But this took an exposure of several hours to produce an image. So, some "development" happened. That is, someone took a look at the existing technology and worked out how to make it work a bit better.

Get it now?
 
jon ryan said:
It's called "development". What happens is, someone makes something to, picking an example at random, create images of scenes. Let's call the original innovator, to pick a name entirely at random, Joseph Nicéphore Niépce. Joe used a medium called bitumen of Judea on which to record an image of his garden. But this took an exposure of several hours to produce an image. So, some "development" happened. That is, someone took a look at the existing technology and worked out how to make it work a bit better.

Get it now?
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But why where they developed? Lenses are not like electronic technology, they don't have the same life span.

If you are happy with lenses that are not sharp fair enough but I'm certainly not.
 
POAH said:
But why where they developed? Lenses are not like electronic technology, they don't have the same life span.

If you are happy with lenses that are not sharp fair enough but I'm certainly not.
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*sigh*

Just say if the concept of technological advancement is too complicated for you and I'll try to explain it again using shorter words. :gag:
 
Alastair said:
Noone has yet taken an interesting photograph of a sharpness/focus test card. You could view that as a challenge, ..
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hmm - there was a sharpness/focus test card free in this months digital photography ... just trying to think of an intersting photo to take of it now.
 
POAH said:
But why where they developed? Lenses are not like electronic technology, they don't have the same life span.

If you are happy with lenses that are not sharp fair enough but I'm certainly not.
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Really? I thought that's exactly what most lens upgrades were about, as well as weight reduction?

One of the most common failure points of older telephotos (300/2.8, 400/2.8 non IS etc) is the focus motor. Once that goes they're effectively expensive doorstops.
 
jon ryan said:
The overwhelming majority of lenses are fine. If you draw the short straw, you have redress under the Sale of Goods Act.

Do you try to find out if your new car can actually do 0-60 in 6.7 seconds before you buy it? Do you use calibrated timing gear to check before you buy?

Well then.
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Took the words out of my mouth Jon, but I was going to say if you bought a new car would you take it for a spin to see if the tyres would last the distance what the manufacturers state :D
 
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jon ryan said:
*sigh*

Just say if the concept of technological advancement is too complicated for you and I'll try to explain it again using shorter words. :gag:
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Ok use shorter words
 
Once upon a time, two blades on your razor gave a shave as smooth as a baby's bum - but now you need at least five blades and a couple of 'lubra-strips' to get a shave that smooth - but is the five-blade mk VII version any sharper? :lol:
 
weybourne said:
Once upon a time, two blades on your razor gave a shave as smooth as a baby's bum - but now you need at least five blades and a couple of 'lubra-strips' to get a shave that smooth - but is the five-blade mk VII version any sharper? :lol:
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No,they are just more expensive and bigger...............:D
 
POAH said:
Why? Because most lenses today have to deal with high pixels counts thus may not be upto the job as they date from the film era. Sharpness also lets you know how useable the lens is and wither or not the lens is built correctly.
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Where does the film era come into the equation with a Tokina 11mm-16mm f2.8 :shrug:
 
POAH said:
sorry but I can't do it using small enough words ;)
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No worries, I have a fairly broad vocabulary so long words will be fine.

But if you can't do it, just try to be a man and admit it, hmmm? Nothing to be ashamed of if a task is beyond you.
 
jon ryan said:
But if you can't do it, just try to be a man and admit it, hmmm? Nothing to be ashamed of if a task is beyond you.
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I thought I saw a pig flying past my window, but it wasnt, just a magpie.
 
jon ryan said:
No worries, I have a fairly broad vocabulary so long words will be fine.

But if you can't do it, just try to be a man and admit it, hmmm? Nothing to be ashamed of if a task is beyond you.
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If you can't understand there is no point in try to explain as you'll never get it.
 
POAH said:
If you can't understand there is no point in try to explain as you'll never get it.
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If you are incapable of explaining, just say so. Otherwise, give your explanation and let's see if I can understand. Or are you pre-judging a result without offering or examining evidence? Guessing, in other words. If the latter, I hope you don't ever think of getting involved in any scientific field!
 
Serious answer to the OP's question

I purchase a spyderLensCal to set up my lenses then stored the results on my D300. Shortly afterwards I remove the settings as they caused more problems than fixed. What I did was set my camera up on one tripod and the Spyderlenscal on another with both set at the same height. Fair enough you might say? then I hit the problem, what distance should the camera be away from the target?. Research showed that different companies had different ideas ,some said a fixed distance others a different distance on a particular mm length of lens, and others quoted percentages of this and that to work out. That left me baffled as to which was correct. I did try different distances and the camera settings for sharpness were different using the same lens each time. Thinking on it futher logically, if the subject is too close to the camera it will be out of focus and too far away no point in taking the photo anyway. So distance can have a vast effect on how sharp a picture will be.

I have always thought 3rd party lenses can never be quite as good as the camera manufacturers own make, obviously there are exceptions and the mm range might not suit the owner. Usually the price reflects this and is a good guide as to sorting the good from the not quite up to standard types

So my advice would be if your happy with the photos then leave well alone, if not send the lens back for recalibration.

Realspeed
 
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People tune their guitars, check their tyre pressures, have thermometers and measuring tapes and scales, have cars and boilers serviced, tweak their PCs, sharpen their lawnmower blades etc. etc.. Wanting to get the best performance from your tools and possessions is not unusual or silly.

What's wrong with verifying that your camera gear is set up for optimum performance, especially if it has a combined value of several thousand pounds - money spent in the deliberate pursuit of perfection? I'm not ashamed to admit that I calibrate every lens/body I own. I think I've a good grasp of the reasons why calibration may be needed and a pretty fair handle on the whys and wherefores of how to do it.

I quite agree with "If it ain't broke don't fix it.", but I like to verify that it is not broken. A 135/2 that is focusing a little off is just going to be a waste. Mine needs +2 with my 5D2 and +11 with my 7D. That latter adjustment is not one I'm going to be content to ignore.
 
jon ryan said:
So, now we've settled that we can get back to the subject, which was you explaining why you think I am in error as you claim in your earlier post:



Go right ahead.
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andy, you should realise by now that poahs posts also follow a "globular rather than a linear structure" He isn't going to explain why you are in error because that would risk you proving that you arent.

He's far more likely to keep on prolonging this pointless diversion until either the thread gets closed or you lose your temper and accuse him of activity more commonly carried out by mythical creatures that live under bridges and eat goats.

my advice - put him on ignore and enjoy a 'reduced provocation' TP experience
 
tdodd said:
People tune their guitars, check their tyre pressures, have thermometers and measuring tapes and scales, have cars and boilers serviced, tweak their PCs, sharpen their lawnmower blades etc. etc.. Wanting to get the best performance from your tools and possessions is not unusual or silly.

What's wrong with verifying that your camera gear is set up for optimum performance, especially if it has a combined value of several thousand pounds - money spent in the deliberate pursuit of perfection? I'm not ashamed to admit that I calibrate every lens/body I own. I think I've a good grasp of the reasons why calibration may be needed and a pretty fair handle on the whys and wherefores of how to do it.

I quite agree with "If it ain't broke don't fix it.", but I like to verify that it is not broken. A 135/2 that is focusing a little off is just going to be a waste. Mine needs +2 with my 5D2 and +11 with my 7D. That latter adjustment is not one I'm going to be content to ignore.
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I don't disagree tim, but it should be in moderation as the point of ensuring you've got a sharp copy is to use the kit to take pictures - we don't want to wind up like those motorheads who spend years and thousands of pounds tuning, tweaking, and modifying their cars, but never actually get out and drive them for fear of the chromy bits getting dirty
 
big soft moose said:
andy, you should realise by now that poahs posts also follow a "globular rather than a linear structure" He isn't going to explain why you are in error because that would risk you proving that you arent.

He's far more likely to keep on prolonging this pointless diversion until either the thread gets closed or you lose your temper and accuse him of activity more commonly carried out by mythical creatures that live under bridges and eat goats.

my advice - put him on ignore and enjoy a 'reduced provocation' TP experience
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Oh, I realise that. It's just that I've had a long, hot day stuck in the office with the sun shining outside, and I needed a little harmless displacement activity. Bating people like that is a little cruel - they can't really help themselves - but they do serve to entertain. For a given value of `entertain`, that is. :)
 
jon ryan said:
Oh, I realise that. It's just that I've had a long, hot day stuck in the office with the sun shining outside, and I needed a little harmless displacement activity. Bating people like that is a little cruel - they can't really help themselves - but they do serve to entertain. For a given value of `entertain`, that is. :)
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I've also just realised i called you 'andy' :bonk: - its been a long day here too, mainly stuck in a sweltering meeting room with people yelling at each other.
 
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