just bought a Canon 450D

Discussion in 'Digital Photography' started by iCheese, Sep 26, 2009.

  1. iCheese macrumors regular

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    May 31, 2006
    #1
    I have a few starting questions that have just popped into my head. This is my first SLR with an autofocusing lens, and my first DSLR.

    1. Is it bad to move the focusing ring while the lens is set to Auto-focus, or while the camera is turned off?

    2. In Auto-P and some other modes, I have the camera set to take both a RAW and JPG copy of the shot. After looking at the two copies on my computer in iPhoto, I noticed that the contrast and color looks a lot different between the two. The JPG seems to have darker colors and so on. Why is this?

    3. I think I read the camera body of the 450D is rated to last 100,000 shots. What happens after I reach that? Does the body just stop working and break down, or is there a very good chance it will last a lot longer than that? Is that number just an average?

    thanks so much for any answers!
     
  2. gkarris macrumors 604

    gkarris

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    #2
    1. No...

    2. RAW is directly from the camera's sensor, JPG is a compressed so colors/exposure may change (in layman's terms) depending on the algorithm.

    3. The world ends - before it does, go out and get a better camera... ;)

    Enjoy your new camera, post pics.

    This is my favorite Canon site:

    http://www.photography-on-the.net
     
  3. iCheese thread starter macrumors regular

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    May 31, 2006
    #3
    1. I wasn't sure if the lens is set to some sort of drive while operating in autofocus mode. I don't exactly know how external autofocusing lenses operate. I don't want to break it!

    Two new questions:

    1. What is a really good book to read for a better understanding of how exposure works. Something that explains to a beginner how aperture, shutter speed, etc all add up to a good picture.

    2. What is the best website for sharing and posting picture galleries? Flickr? Photobucket?

    Thanks
     
  4. iBookG4user macrumors 604

    iBookG4user

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    #4
    This is not always true though! If your lens is not equipped with USM, you do not want to turn the focus ring if it is set to autofocus, it can ruin the autofocus motor. However, if your lens does have USM, then you can turn the focus ring while it is set to Autofocus and have no adverse effects.

    I highly recommend Understanding Exposure by Bryan Peterson, great book that really shows you the fundamentals of photography :)

    Personally I use Deviantart, although Flickr is also a good website to share them on. Another one would be Smugmug.
     
  5. iCheese thread starter macrumors regular

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    #5
    I was checking out the Understanding Exposure book on amazon, as I had heard it was recommended, but it seemed like it dealt more with advanced picture taking techniques. Does it still go into basic stuff for a beginner?

    The only lens I have now is the kit lens that came with the camera, and it has image stabilization. Does this mean it is ok to move th focusing ring whenever?
     
  6. iBookG4user macrumors 604

    iBookG4user

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    #6
    It does go into the basics as well as a bit more advanced, so it should be fine for you. And your lens does not have USM, so no, you should not turn the focus ring without it being set to manual focus.
     
  7. Techhie macrumors 65816

    Techhie

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    #7
    Moving the MF ring on that lens (18-55mm IS kit) will damage the lens' AF motor if it is not set to be in manual focus. With JPGs, the camera is set to apply a set WB to the photo before export, as with RAW you have to do this yourself. The 100,000 shot life is simply an average of how long the shutter (that thing that flips up to expose the sensor) will last. You may get more or less than 100,000 actuations, and if it the shutter breaks at any point Canon does fairly cheap repairs.
     
  8. iCheese thread starter macrumors regular

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    May 31, 2006
    #8
    Good to hear about the book, I will look for it now.

    I am glad I got clarification about the lens. I was avoiding touching the focus ring when it wasn't in MF mode. Does the damage only occur when the camera is turned on, or will it also be bad when the camera is turned off?
     
  9. Vogue Harper macrumors 6502

    Vogue Harper

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    #9
    That's true - I busted a 50mm f1:8 lens by accidentally turning the focus ring while it was set to autofocus. It made a horrible grinding noise next time it tried to focus and wouldn't autofocus properly after that. Thank goodness it was my cheapest lens though.

    I would also recommend the Bryan Peterson book. It is excellent. Teaches you the basics about exposure (which is really what photography is technically) and gives you EXIF information for all the shots in his book so you can go and replicate them if you wanted to. I have bought copies for a few of my friends when they got into DSLR photography.
     
  10. Techhie macrumors 65816

    Techhie

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    #10
    Doesn't matter if it is on or off. Imagine the AF motor being a hand that grabs the AF ring when AF is on, and lets it go when MF is on. If you try to turn the ring while the "hand" is on it, you will feel resistance and if you try hard enough the AF motor will twist and break. Not a very great design, but what do you expect for a cheap kit lens? I had my 450 stolen last week, and I was just about to order a nice USM lens for it that doesn't have this problem :(
     
  11. iCheese thread starter macrumors regular

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    May 31, 2006
    #11
    Damn, sorry to hear about your stolen camera. I hate thieves so much.

    Your description of the focusing mechanism makes a lot of sense. I was hoping that I could somehow bring the lens all the way in before storing it or whatever, so I am guessing I will have to put it in MF in order to do this all the time.

    Most of the camera bags I have seen store the camera with the lens facing down, and I am concerned that if the weight of the camera is resting somewhat on the lens, then maybe unnecessary stress will happen. Is this a non-issue?

    Also, to everyone who recommended Understanding Exposure, thank you so much. This is exactly the book I was wanting.
     
  12. Techhie macrumors 65816

    Techhie

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    #12
    It shouldn't be a problem, just make sure that you put the lens caps on both ends before storing it away, and also put the zoom/focus ring all the way down.
     
  13. munkees macrumors 65816

    munkees

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    #13
    I always set my lenses to MF when not in use.
     
  14. iCheese thread starter macrumors regular

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    May 31, 2006
    #14
    I meant talking about a lens that is already attached to the camera. If the lens is attached, and the whole camera plus lens is facing down, then some of the weight of the camera might be put on the lens. This is why I was thinking about whether or not it would be worthwhile to set the lens to MF and retract the lens assembly fully before putting it in a bag. I don't know how much it matters though. I know the lens has to be rotated for movement, but I also dont know if any slight force exerted straight back on the lens would be bad or not.

    This is what I am considering doing.
     
  15. MrSmith macrumors 68040

    MrSmith

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    Nov 27, 2003
    #15
    How about polarizers?

    I'd like to add a question regarding twisting the end of the lens. I've ordered a polarizer for my stock lenses that came with the camera. How about twisting those?
     
  16. ftaok macrumors 601

    ftaok

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    #16
    Regarding the AF/manual focus adjust issue ...

    Not all USM is created equal. Canon has two flavors of USM. The better version (ring-type) allows for full-time manual focus overide. The lesser version (micro-motor) does not. You can manually focus while in AF mode on a ring-type USM lens, but typically not on a micro-motor USM lens.

    There aren't too many Canon lenses with the micro motor USM, but they exist.

    I believe the EF-S 18-200 IS USM uses the lesser version of USM.

    The EF 70-300 IS USM is one of the more popular zooms, and it uses the micro-motor USM.
     
  17. scaredpoet macrumors 604

    scaredpoet

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    #17

    The circualr polarizong filter? that you can twist at any time. It's a free-wheeling kinda of ring and that turns independent of the lens focusing ring.
     
  18. Vogue Harper macrumors 6502

    Vogue Harper

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    #18
    No problem as circular polarisers turn within the filter ring itself and the force required to turn them should not be enough to turn the auto focus motor.
     

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