Results 1 to 12 of 12

Thread: A Few Newbie Questions

  1. #1
    Member
    Join Date
    Dec 2006
    Location
    Serangoon
    Posts
    684

    Default A Few Newbie Questions

    Hi, sorry got some amateur problems that i do not understand. Really need some help.

    1. F number usually refers to aperture due to my very limited knowledge. There is always a F number range on lens. What does that stands for? Is it the maximum size the aperture can open till?

    2. Does image quality and sharpness depends more on the sensor, or the lens, or the camera body/model?

    3. Related to question 2, does it means using a older DSLR model but using it with a very good lens, will still give you brilliant results or not?

    4. Is there any difference between say bigger lens 72mm and say smaller ones like 58mm lens?

    5. Does it mean that a poor sensor with a very high megapixel number will still yield very poor results?

    6. Is it a must to get a dry box or dry cab for a prosumer camera?

    Thanks

  2. #2

    Default Re: A Few Newbie Questions

    1. F number usually refers to aperture due to my very limited knowledge. There is always a F number range on lens. What does that stands for? Is it the maximum size the aperture can open till?
    for prime lenses the largest aperture is constant, for zoom lenses it tends to change with the focal length (not on all tough), the range indicates this change. The smallest aperture is usually not indicated in the lense name, only on the aperture adjustment ring.

    2. Does image quality and sharpness depends more on the sensor, or the lens, or the camera body/model?
    lens and mathematic algorithms used for the interpretation of the data.

    3. Related to question 2, does it means using a older DSLR model but using it with a very good lens, will still give you brilliant results or not?
    yes also an older DSLR will still produce good results, however older sensor may be more sensible to noise....

    4. Is there any difference between say bigger lens 72mm and say smaller ones like 58mm lens?
    bigger as in focal length or bigger as in diameter of lense?

    5. Does it mean that a poor sensor with a very high megapixel number will still yield very poor results?
    yes

    6. Is it a must to get a dry box or dry cab for a prosumer camera?
    if you dont keep it in aircon conditions and you prefer to have no mould on your lens, yes

  3. #3
    Member
    Join Date
    Dec 2006
    Location
    Serangoon
    Posts
    684

    Default Re: A Few Newbie Questions

    Thank you Michael for helping me make sense on those things.

    For question 4, i was referring to the diameter of the lens. Thanks once more.

    Zhiliang

  4. #4
    Senior Member
    Join Date
    Aug 2005
    Location
    Tanjong Katong
    Posts
    3,710

    Default Re: A Few Newbie Questions

    Quote Originally Posted by Zhiliang View Post
    Thank you Michael for helping me make sense on those things.

    For question 4, i was referring to the diameter of the lens. Thanks once more.

    Zhiliang
    Diameter of the lens? Do you mean filter thread size?

    Usually (not always), the bigger the filter thread, the faster the lens. Faster lens usually come with quality (not always too) and price (this one always ).

    Regards,
    Arto.

  5. #5
    Senior Member
    Join Date
    Jan 2006
    Location
    Dreamy Nikon Land
    Posts
    2,874

    Default Re: A Few Newbie Questions

    The diameter of the lens, normally if larger, will means more light can enter. Thus, normally they can allow a smaller f-number, what we normally called fast lens.

    However, because it is more difficult to make a large piece of glass, thus they are more expensive.
    Andy Ang :lovegrin: - "A Photo speaks a thousand words. Have you spoken today?"
    APAD | Blog

  6. #6
    Member
    Join Date
    Dec 2006
    Location
    Serangoon
    Posts
    684

    Default Re: A Few Newbie Questions

    Thanks....

  7. #7
    Senior Member
    Join Date
    Jan 2006
    Location
    West Legion
    Posts
    7,751

    Default Re: A Few Newbie Questions

    Quote Originally Posted by Artosoft View Post
    Diameter of the lens? Do you mean filter thread size?

    Usually (not always), the bigger the filter thread, the faster the lens. Faster lens usually come with quality (not always too) and price (this one always ).

    Regards,
    Arto.
    the larger diameter is your lens, the larger the hole in your pocket.

  8. #8
    Member
    Join Date
    Nov 2006
    Location
    Singapore
    Posts
    289

    Default Re: A Few Newbie Questions

    Quote Originally Posted by ExplorerZ View Post
    the larger diameter is your lens, the larger the hole in your pocket.
    Agree...

    To TS, as said before, I only would like to add a little bit information

    f number is refer to the lens capability of open or close. Normally must write f/2.8 but people are lazy and only type f2.8.

    If a lens focal lens is 50mm f/1.8 mean the maximum diameter the aperture could open is equal f/1.8=50/1.8=27.77mm

    For longer lenses, it is hard to achieve large f number (means open wider) because let compare 200 f/4 and 200 f/2.8

    The maximum aperture for f/2.8=200/2.8=71mm
    The maximum aperture for f/4=200/4=50mm

    So you can see the difference..That's why the longer lense often requires larger barrel (results in all glasses inside lens are required to be larger in size, thus,harder to fabricate and in quality control, increased in weight...), so the the price for long lens increase in exponential function...


    Just go compare the 70-200 f/4 and 700-200f/2.8..He he..You will see the prices are much much different...
    A person is useless unless he is standing up for himself, for his future, and for his dreams.

  9. #9
    Senior Member
    Join Date
    Aug 2005
    Location
    Tanjong Katong
    Posts
    3,710

    Default Re: A Few Newbie Questions

    Quote Originally Posted by standingup View Post
    ...Just go compare the 70-200 f/4 and 700-200f/2.8..He he..You will see the prices are much much different...
    Can also compare 50/1.4 and 50/1.8 price . It is less than 1 stop difference. Same made in China.

    Regards,
    Arto.

  10. #10
    Senior Member
    Join Date
    Sep 2004
    Location
    Cons digger.
    Posts
    3,924

    Default Re: A Few Newbie Questions

    wow.. so many pros give input already.. don't mind me amatuer give some also.

    1. F number usually refers to aperture due to my very limited knowledge. There is always a F number range on lens. What does that stands for? Is it the maximum size the aperture can open till?
    Yes.. single digit f-numbers means constant throughout zoom range.
    eg:70-200/2.8 means from 70mm to 200mm max aperture is f2.8.
    2 numbers means a range of max aperture depending on focal length.
    70-300/3.5-4.6 means at 70mm max aperture is f3.5 at 300 is f4.6


    2. Does image quality and sharpness depends more on the sensor, or the lens, or the camera body/model?
    Both. But more on the lens. If you have a very sharp lens but only 2megapixels with lousy sensor the image will be sucky. vice-versa, a fantastic sensor with lousy lens will also give crappy picture.


    3. Related to question 2, does it means using a older DSLR model but using it with a very good lens, will still give you brilliant results or not?
    digital bodies these days up to 3years back can give quite impressive results.

    4. Is there any difference between say bigger lens 72mm and say smaller ones like 58mm lens?
    yes, as previously mentioned. bigger thread size bigger hole in wallet.

    5. Does it mean that a poor sensor with a very high megapixel number will still yield very poor results?
    My personal opinion yes. Unlike the days of film where you can change the film if you didn't like certain tones or colours, but with digital, the processing style is stuck and you can't do anything about it other than post process it afterwards to get the results you want. That said for an inferior sensor that is inherently noisy, you can't do much about it. It's better to get clean and good output from the start.


    6. Is it a must to get a dry box or dry cab for a prosumer camera?
    individual preference. I don't stay in an aircon room and my "hand-me-down" cams previously didn't have that luxury as well. They've been enjoying the same humid environment as me without fungus. Then I bought an air-tight box and use silica gel to pamper them. 2 years after that, I could afford a small dry cab and now it's storing my stuff neatly inside.


    Thanks
    Last edited by yanyewkay; 26th January 2007 at 11:07 AM.
    “How fortunate for leaders that men do not think.” - Adolf Hitler

  11. #11
    Member
    Join Date
    Dec 2006
    Location
    Serangoon
    Posts
    684

    Default Re: A Few Newbie Questions

    Quote Originally Posted by yanyewkay View Post
    wow.. so many pros give input already.. don't mind me amatuer give some also.

    1. F number usually refers to aperture due to my very limited knowledge. There is always a F number range on lens. What does that stands for? Is it the maximum size the aperture can open till?
    Yes.. single digit f-numbers means constant throughout zoom range.
    eg:70-200/2.8 means from 70mm to 200mm max aperture is f2.8.
    2 numbers means a range of max aperture depending on focal length.
    70-300/3.5-4.6 means at 70mm max aperture is f3.5 at 300 is f4.6


    2. Does image quality and sharpness depends more on the sensor, or the lens, or the camera body/model?
    Both. But more on the lens. If you have a very sharp lens but only 2megapixels with lousy sensor the image will be sucky. vice-versa, a fantastic sensor with lousy lens will also give crappy picture.


    3. Related to question 2, does it means using a older DSLR model but using it with a very good lens, will still give you brilliant results or not?
    digital bodies these days up to 3years back can give quite impressive results.

    4. Is there any difference between say bigger lens 72mm and say smaller ones like 58mm lens?
    yes, as previously mentioned. bigger thread size bigger hole in wallet.

    5. Does it mean that a poor sensor with a very high megapixel number will still yield very poor results?
    My personal opinion yes. Unlike the days of film where you can change the film if you didn't like certain tones or colours, but with digital, the processing style is stuck and you can't do anything about it other than post process it afterwards to get the results you want. That said for an inferior sensor that is inherently noisy, you can't do much about it. It's better to get clean and good output from the start.


    6. Is it a must to get a dry box or dry cab for a prosumer camera?
    individual preference. I don't stay in an aircon room and my "hand-me-down" cams previously didn't have that luxury as well. They've been enjoying the same humid environment as me without fungus. Then I bought an air-tight box and use silica gel to pamper them. 2 years after that, I could afford a small dry cab and now it's storing my stuff neatly inside.


    Thanks

    Thanks so much, they have been very very helpful. Does ALLl lens of DSLR have the real focal length as stated unlike a prosumer which might only have a equavalent?

  12. #12
    Senior Member
    Join Date
    Dec 2005
    Location
    KFC
    Posts
    1,776

    Default Re: A Few Newbie Questions

    Quote Originally Posted by Zhiliang View Post
    Thanks so much, they have been very very helpful. Does ALLl lens of DSLR have the real focal length as stated unlike a prosumer which might only have a equavalent?
    yes, all the lens of dslr state their exact focal length. to calculate the equivalent focal length for dslr, it depends on the camera brand and which camera already...

    for nikon dslr, the whole lineup of dslr is 1.5x
    for olympus dslr, the whole lineup of dslr is 2x
    for canon dslr, there are 1.0x, 1.3x and 1.6x

    1.5x means if the lens focal length is 70-200, the equivalent focal length is 105mm to 300mm
    09 Oct 09 officially marks the date I become a canon convert.

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
  •