Results 1 to 14 of 14

Thread: Lens Testing.

  1. #1

    Default Lens Testing.

    Bros, I am going to build a studio to test lens performance, which includes, sharpness (MTF and resolution as well), distortion, LC and HFOV etc. Wanno to know how many of your guys may be interested in these kind of testing.
    Based on the how many focal lengths to be tested, may have 10 to 20 dollars charge. Please comments.

  2. #2

    Default Re: Lens Testing.

    Since no boby reply. I'd make it clearer: my testing studio is just for fun.

  3. #3

    Default Re: Lens Testing.

    Most of compact digital cameras now are 12x, 15x and even 20x. Surely, you can not have good performance in every focal length, also you can not expect they are as good as normal 3x compact digital.

    How good is the MTF, which focal length is the softest point, wide, midium or tele? How much is the Lateral color at wide and tele? How much is the light falloff when wide open?

    For DSLR, how good is the distortion at the wide angle side? How soft the MTF should be?

    From the testing, you may know how to use your current and choose next lens.

  4. #4

    Default Re: Lens Testing.

    How do you actually generate the MTFs?

    This lens testing may be useful to those who want to find out if they have a bad sample of lens or after ultimate lens resolution. Then again, you may need to establish the benchmark for which the lens are judge upon and will be rather tedious.

    Perhaps you care to elaborate more on what to expect?

  5. #5
    Member
    Join Date
    Oct 2007
    Location
    Eastland
    Posts
    235

    Default Re: Lens Testing.

    Quote Originally Posted by eng01170 View Post
    How do you actually generate the MTFs?

    This lens testing may be useful to those who want to find out if they have a bad sample of lens or after ultimate lens resolution. Then again, you may need to establish the benchmark for which the lens are judge upon and will be rather tedious.

    Perhaps you care to elaborate more on what to expect?
    I am interested. What brand of lens are you able to test? Nikon, Canon, Sony? What kind of analysis do you provide?

  6. #6

    Default Re: Lens Testing.

    To eng01170, yes, you really asked the questions.

    For MTF measurement, one need work out the knife-edge spread function (distribution) and then calculate.
    To have a benchmark which could be applied to all lenses is impossible. For example, for a zoom lens, wide angle side may suffer from more distortion, light falloff and lateral color, also the MTF drops a lot at the edge; at tele side, however, the MTF may be lower but be more uniform for the whole aperture, also lateral color may be obverious; at normal side (middle focal length), lens may have most of aberration balanced and perform better.
    Different company has different design requirement, like Nikon and Canon, they may concern lens performance more on the centre than on edge, but for Pentax, I saw some lens have quite uniform distribution of MTF. So, when conduct testing, I have to bear all these factors in mind so that the test result come out is complete.

    Any way, all the values I test is quantitative, based on which I will do some comparison and advise.

    To king kong,

    Fine. Thanks.
    Basically, I can test all the lens you mentioned and pointand shoot camera as well. However, manual focus lens may not be accurate, I suppose.
    I am testing the optical performance of the lens. I can test focal length, field of view, MTF, light falloff, lateral color and distortion. I am not going to test something like, the AF speed and noise of motor etc.


    Hope more people show they interest and let me know by reply my post.

  7. #7
    Member
    Join Date
    Oct 2007
    Location
    Eastland
    Posts
    235

    Default Re: Lens Testing.

    Quote Originally Posted by camoptics View Post
    To eng01170, yes, you really asked the questions.

    For MTF measurement, one need work out the knife-edge spread function (distribution) and then calculate.
    To have a benchmark which could be applied to all lenses is impossible. For example, for a zoom lens, wide angle side may suffer from more distortion, light falloff and lateral color, also the MTF drops a lot at the edge; at tele side, however, the MTF may be lower but be more uniform for the whole aperture, also lateral color may be obverious; at normal side (middle focal length), lens may have most of aberration balanced and perform better.
    Different company has different design requirement, like Nikon and Canon, they may concern lens performance more on the centre than on edge, but for Pentax, I saw some lens have quite uniform distribution of MTF. So, when conduct testing, I have to bear all these factors in mind so that the test result come out is complete.

    Any way, all the values I test is quantitative, based on which I will do some comparison and advise.

    To king kong,

    Fine. Thanks.
    Basically, I can test all the lens you mentioned and pointand shoot camera as well. However, manual focus lens may not be accurate, I suppose.
    I am testing the optical performance of the lens. I can test focal length, field of view, MTF, light falloff, lateral color and distortion. I am not going to test something like, the AF speed and noise of motor etc.


    Hope more people show they interest and let me know by reply my post.
    I am very interested to test out some of my Nikon Lenses. Are you fully setup now? Where are you located? How to contact you? Mayby you can PM me.

  8. #8

    Default Re: Lens Testing.

    Sorry, have not set up yet. Thanks.

  9. #9
    Senior Member
    Join Date
    Jan 2004
    Location
    Catchment Area
    Posts
    2,441

    Default Re: Lens Testing.

    Maybe, you can elaborate on the proposed equipment you are gonna to use, the size of your studio, whether you're gonna to offer your service full time, your charges, time frame to set up and perhaps some other information for us.

    I suppose the lens testing to be carried out at 3m or at most 6m and not any further.
    I love big car, big house, big lenses, but small apertures.

  10. #10

    Default Re: Lens Testing.

    Hi, Smallaperture, seems to me you are very good at lens and Optics.

    My studio have not set up yet, in my plan, it may be that kind of size you mentioned.

    To test lens is just my hobby, from which I could explore my interest. No, I am not going to run it as business. As for the charge, it is because cost a lot of my time. As such, probably I can do it only in weekend.

    If very few people are interested in it, I may delay the setup. No point to have a setup can only play on a few lenses again and again.

  11. #11

    Default Re: Lens Testing.

    if you want to play with the lens, I can provide you with my lens in return for the test results

    I am not sure if I am willing to pay for such a service. It is "interesting" to know lab test results but ultimately one can do it by himself by shooting test shots.

    maybe someone can help to compile it into a website, which may prove valuable as time passes.

  12. #12

    Default Re: Lens Testing.

    Thanks. You are right in many sense.

    Anyway, some people may be interested in this kind of technical testing about the lens.

  13. #13

    Default Re: Lens Testing.

    Bros, Pls vote if you are interested in the testing.
    Thanks.

  14. #14
    Senior Member
    Join Date
    Jan 2004
    Location
    Catchment Area
    Posts
    2,441

    Default Re: Lens Testing.

    Quote Originally Posted by camoptics View Post
    Hi, Smallaperture, seems to me you are very good at lens and Optics.

    My studio have not set up yet, in my plan, it may be that kind of size you mentioned.

    To test lens is just my hobby, from which I could explore my interest. No, I am not going to run it as business. As for the charge, it is because cost a lot of my time. As such, probably I can do it only in weekend.

    If very few people are interested in it, I may delay the setup. No point to have a setup can only play on a few lenses again and again.
    Hahaha, paiseh leh. I know very little actually. In CS, there are many gurus, experts, specialists in Optics, in digital photo, in post-processing and so forth.

    Anyway, all the best to your project.
    I love big car, big house, big lenses, but small apertures.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •