How to test a second hand lens?
Discussion
Test for what?
Mechanically does it work. If relevant, electrical contacts - do they work? When mounted does body recognise it? If manual, input the lens details to the body.
Take pictures: does it stop down, or not. Does it expose (aperture) the same as another known lens. Is it as sharp as you would expect. If relevant, does it autofocus; does it need the autofocus fine tune carried out.
Off you go....
Mechanically does it work. If relevant, electrical contacts - do they work? When mounted does body recognise it? If manual, input the lens details to the body.
Take pictures: does it stop down, or not. Does it expose (aperture) the same as another known lens. Is it as sharp as you would expect. If relevant, does it autofocus; does it need the autofocus fine tune carried out.
Off you go....
flat-planedCrank said:
I'd probably take photos of something like a brick wall from varying distances / apertures and check if it's equally sharp across the frame too.
Just a rudimentary check to see if anything has become misaligned.
Maybe a burst of shots as well to see if the results are consistent - though if you don't plan to us it for bursts there may be less point to that.Just a rudimentary check to see if anything has become misaligned.
However if you are checking AF try a few different subjects and remember that the camera's AF system has certain requirements for contrast if consistent results are to be achieved. You need a subject that gives the camera half a chance to perform ...
What I want to see is both ends of the aperture spectrum, any CA and what the bokeh's like. Sharpness, unless it's a million miles out and needs sending off wouldnt bother me that much. I've always found original lenses seem to have slightly better colour rendition and sharpness over the 3rd party ones, but that's not put me off buying
On first inspection I would say that is not wonderfully sharp ... however sometimes thangs are not and one needs to know more before making an informed decision.
The first problem with your example, from this end of the 'net, is that it has been re-sized by Photobucket and no doubt has had a few other adjustments along the way before it hits my screen so it's really difficult to know whether what I am seeing is what you are seeing. If it is and the lens is operating within its expected range and setings and so on, then it looks very soft for a dSLR lens. Or any lens for that matter, short of something from one of the "fun" lens manufacturers.
Secondly, if you used AF, there is a possible question mark about how well your camera's AF can cope with the subject matter - and maybe even what settings you are using for AF. However there is nothing in the image that looks sharp to me. So I think we canleave that for a while.
Do you have a similar test shot using the same camera but another lens that you feel is a true representation of the AF capability? Better still, the same shot taken with a different lens. Maybe.
The first problem with your example, from this end of the 'net, is that it has been re-sized by Photobucket and no doubt has had a few other adjustments along the way before it hits my screen so it's really difficult to know whether what I am seeing is what you are seeing. If it is and the lens is operating within its expected range and setings and so on, then it looks very soft for a dSLR lens. Or any lens for that matter, short of something from one of the "fun" lens manufacturers.
Secondly, if you used AF, there is a possible question mark about how well your camera's AF can cope with the subject matter - and maybe even what settings you are using for AF. However there is nothing in the image that looks sharp to me. So I think we canleave that for a while.
Do you have a similar test shot using the same camera but another lens that you feel is a true representation of the AF capability? Better still, the same shot taken with a different lens. Maybe.
LongQ said:
On first inspection I would say that is not wonderfully sharp ... however sometimes thangs are not and one needs to know more before making an informed decision.
The first problem with your example, from this end of the 'net, is that it has been re-sized by Photobucket and no doubt has had a few other adjustments along the way before it hits my screen so it's really difficult to know whether what I am seeing is what you are seeing. If it is and the lens is operating within its expected range and setings and so on, then it looks very soft for a dSLR lens. Or any lens for that matter, short of something from one of the "fun" lens manufacturers.
Secondly, if you used AF, there is a possible question mark about how well your camera's AF can cope with the subject matter - and maybe even what settings you are using for AF. However there is nothing in the image that looks sharp to me. So I think we canleave that for a while.
Do you have a similar test shot using the same camera but another lens that you feel is a true representation of the AF capability? Better still, the same shot taken with a different lens. Maybe.
Ah right gotcha. The first problem with your example, from this end of the 'net, is that it has been re-sized by Photobucket and no doubt has had a few other adjustments along the way before it hits my screen so it's really difficult to know whether what I am seeing is what you are seeing. If it is and the lens is operating within its expected range and setings and so on, then it looks very soft for a dSLR lens. Or any lens for that matter, short of something from one of the "fun" lens manufacturers.
Secondly, if you used AF, there is a possible question mark about how well your camera's AF can cope with the subject matter - and maybe even what settings you are using for AF. However there is nothing in the image that looks sharp to me. So I think we canleave that for a while.
Do you have a similar test shot using the same camera but another lens that you feel is a true representation of the AF capability? Better still, the same shot taken with a different lens. Maybe.
Apart from any PB resize it's as is.
Manual focus of a 400mm FD fit lens on a 1000D with a converter. Finding correct focus was actually quite difficult and was the first thing I thought of when I saw the image for the first time.
I'm going to try some sharpening with smart photo editor tonight but yes the initial result isn't really "great".
Still I'd rather find the limitations with a £59 lens/converter combo than try something more exotic and still fall short of expectations.
All good fun though and a good learning experience.
cheers
Mo.
Edited by Mojocvh on Monday 3rd June 20:58
Mojocvh said:
LongQ said:
On first inspection I would say that is not wonderfully sharp ... however sometimes thangs are not and one needs to know more before making an informed decision.
The first problem with your example, from this end of the 'net, is that it has been re-sized by Photobucket and no doubt has had a few other adjustments along the way before it hits my screen so it's really difficult to know whether what I am seeing is what you are seeing. If it is and the lens is operating within its expected range and setings and so on, then it looks very soft for a dSLR lens. Or any lens for that matter, short of something from one of the "fun" lens manufacturers.
Secondly, if you used AF, there is a possible question mark about how well your camera's AF can cope with the subject matter - and maybe even what settings you are using for AF. However there is nothing in the image that looks sharp to me. So I think we canleave that for a while.
Do you have a similar test shot using the same camera but another lens that you feel is a true representation of the AF capability? Better still, the same shot taken with a different lens. Maybe.
Ah right gotcha. The first problem with your example, from this end of the 'net, is that it has been re-sized by Photobucket and no doubt has had a few other adjustments along the way before it hits my screen so it's really difficult to know whether what I am seeing is what you are seeing. If it is and the lens is operating within its expected range and setings and so on, then it looks very soft for a dSLR lens. Or any lens for that matter, short of something from one of the "fun" lens manufacturers.
Secondly, if you used AF, there is a possible question mark about how well your camera's AF can cope with the subject matter - and maybe even what settings you are using for AF. However there is nothing in the image that looks sharp to me. So I think we canleave that for a while.
Do you have a similar test shot using the same camera but another lens that you feel is a true representation of the AF capability? Better still, the same shot taken with a different lens. Maybe.
Apart from any PB resize it's as is.
Manual focus of a 4000mm FD fit lens on a 1000D with a converter. Finding correct focus was actually quite difficult and was the first thing I thought of when I saw the image for the first time.
I'm going to try some sharpening with smart photo editor tonight but yes the initial result isn't really "great".
Still I'd rather find the limitations with a £59 lens/converter combo than try something more exotic and still fall short of expectations.
All good fun though and a good learning experience.
cheers
Mo.
The big problem is starting with less than optimal material as the effect is to over correct. [silk purse/sows ear]
Thanks for taking the time BTW.
Mo.
Well sorry if you feel miffed but you got plenty of good advice, and part of communication is not getting the focal length wrong by a factor of 10!
Two things to ponder: (1) 'You get what you pay for' - a 400mm £59 lens is never going to be good (2) The best way to judge a lens is by the results it gives.
What were you expecting, a link to some software that would say the lens was very good? The camera is fine, it's the milk bottle in front of it that's killing the results
Two things to ponder: (1) 'You get what you pay for' - a 400mm £59 lens is never going to be good (2) The best way to judge a lens is by the results it gives.
What were you expecting, a link to some software that would say the lens was very good? The camera is fine, it's the milk bottle in front of it that's killing the results
Simpo Two said:
Well sorry if you feel miffed but you got plenty of good advice, and part of communication is not getting the focal length wrong by a factor of 10!
Two things to ponder: (1) 'You get what you pay for' - a 400mm £59 lens is never going to be good (2) The best way to judge a lens is by the results it gives.
What were you expecting, a link to some software that would say the lens was very good? The camera is fine, it's the milk bottle in front of it that's killing the results
I think I'll just leave it as it is.Two things to ponder: (1) 'You get what you pay for' - a 400mm £59 lens is never going to be good (2) The best way to judge a lens is by the results it gives.
What were you expecting, a link to some software that would say the lens was very good? The camera is fine, it's the milk bottle in front of it that's killing the results
Ah ha!
OK, which 400mm lens and which FD to EOS converter?
Some quick observations.
There are some rather ungood cheap converters and some slightly better ones in the "with glass" field. I have one (Kood) that allows removal of the added lens if you don't need focus to infinity. Or you can do it properly with a glassless brass adapter from Ed Mika - excellent but not economy prices.
Next. Manual MF of an fd lens on a digital body is tricky. Also you may need to consider what the min focus distance is.
Yes they may need a lot of sharpening, even when focus is good. DoF can be very narrow indeed.
There is usually a sweet spot combo that works so well it makes the rest look poor.
Action shots are a challenge! But if you can pre-focus on where the target will be the potential should be tremendous.
What are you thinking of using it for?
OK, which 400mm lens and which FD to EOS converter?
Some quick observations.
There are some rather ungood cheap converters and some slightly better ones in the "with glass" field. I have one (Kood) that allows removal of the added lens if you don't need focus to infinity. Or you can do it properly with a glassless brass adapter from Ed Mika - excellent but not economy prices.
Next. Manual MF of an fd lens on a digital body is tricky. Also you may need to consider what the min focus distance is.
Yes they may need a lot of sharpening, even when focus is good. DoF can be very narrow indeed.
There is usually a sweet spot combo that works so well it makes the rest look poor.
Action shots are a challenge! But if you can pre-focus on where the target will be the potential should be tremendous.
What are you thinking of using it for?
LongQ said:
Ah ha!
OK, which 400mm lens and which FD to EOS converter?
Some quick observations.
There are some rather ungood cheap converters and some slightly better ones in the "with glass" field. I have one (Kood) that allows removal of the added lens if you don't need focus to infinity. Or you can do it properly with a glassless brass adapter from Ed Mika - excellent but not economy prices.
Next. Manual MF of an fd lens on a digital body is tricky. Also you may need to consider what the min focus distance is.
Yes they may need a lot of sharpening, even when focus is good. DoF can be very narrow indeed.
There is usually a sweet spot combo that works so well it makes the rest look poor.
Action shots are a challenge! But if you can pre-focus on where the target will be the potential should be tremendous.
What are you thinking of using it for?
well with a price of £39 you wont be surprised to hear it's a goog looking Tokina 400 f6.8. I was hoping to piggyback it with my C8 sct for some less than widefields...OK, which 400mm lens and which FD to EOS converter?
Some quick observations.
There are some rather ungood cheap converters and some slightly better ones in the "with glass" field. I have one (Kood) that allows removal of the added lens if you don't need focus to infinity. Or you can do it properly with a glassless brass adapter from Ed Mika - excellent but not economy prices.
Next. Manual MF of an fd lens on a digital body is tricky. Also you may need to consider what the min focus distance is.
Yes they may need a lot of sharpening, even when focus is good. DoF can be very narrow indeed.
There is usually a sweet spot combo that works so well it makes the rest look poor.
Action shots are a challenge! But if you can pre-focus on where the target will be the potential should be tremendous.
What are you thinking of using it for?
Interestingly I've just unscrewed the converter center element, it's an air spaced doublet, took some jiggling and manipulating to get both elements back together looks something like a T ring with some gubbins in the middle
and even then the elements were not really tight in the holder.... 
Yep the converters "work" but as always it's swings and roundabouts, the difficulty is when you have a lens that is a bit out of the ball park, it could be the costs of a "bespoke" conversion make it totally counter productive tbh.
Yes, Ed Mika -some good ideas here but same as above-no one off's and lets be honest here, throwing good money after a small amount of bad.
I think a final test of the converter will be using the lens as intended on a film camera of it's era. That will show the failings of lens, converter or both.
cheers
Mo.
Mojocvh said:
well with a price of £39 you wont be surprised to hear it's a goog looking Tokina 400 f6.8. I was hoping to piggyback it with my C8 sct for some less than widefields...
Interestingly I've just unscrewed the converter center element, it's an air spaced doublet, took some jiggling and manipulating to get both elements back together looks something like a T ring with some gubbins in the middle and even then the elements were not really tight in the holder....
Yep the converters "work" but as always it's swings and roundabouts, the difficulty is when you have a lens that is a bit out of the ball park, it could be the costs of a "bespoke" conversion make it totally counter productive tbh.
Yes, Ed Mika -some good ideas here but same as above-no one off's and lets be honest here, throwing good money after a small amount of bad.
I think a final test of the converter will be using the lens as intended on a film camera of it's era. That will show the failings of lens, converter or both.
cheers
Mo.
Hmm.Interestingly I've just unscrewed the converter center element, it's an air spaced doublet, took some jiggling and manipulating to get both elements back together looks something like a T ring with some gubbins in the middle
and even then the elements were not really tight in the holder.... Yep the converters "work" but as always it's swings and roundabouts, the difficulty is when you have a lens that is a bit out of the ball park, it could be the costs of a "bespoke" conversion make it totally counter productive tbh.
Yes, Ed Mika -some good ideas here but same as above-no one off's and lets be honest here, throwing good money after a small amount of bad.
I think a final test of the converter will be using the lens as intended on a film camera of it's era. That will show the failings of lens, converter or both.
cheers
Mo.
In period Vivitar were the alternative (to Canon) lens of choice. Tamron were popular because you bought a mount with a standard lens and so one lens could, in theory, fit several bodies.
Sigma and Tokina vied for third place and then came the others - Kiron ( I have one of their 28mm lenses - huge disappointment) and Cosina (Whatever happens to them ... oh ... still going strong ....)
Yes they are marginal although I inadvertently picked up a Vivitar Series 1 70-210 (or thereabouts) when I bought a Canon F1 body a few years ago and that can be made to work quite well, considering).
However the real fun is to get hold of one of the big old "white" primes if you can.
Still a challenge to use and get good results but if that fails at least you keep fit whilst lugging it around practicing.
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