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Thread: Tamron 1.4xTC + Kenko 2xTC

  1. #1

    Default Tamron 1.4xTC + Kenko 2xTC

    Hi,
    I have a tamron 1.4xTC and Kenko 2xTC, can i add them up together and use on my Sigma 500mm lens? Wanna take a shot of the moon... Saw some beautiful moon shots so wanna see if i can get the details of the crater...

    btw, i'm using Alpha 200... so anyone has try to stack them up before? got compatibility issue?

  2. #2

    Default Re: Tamron 1.4xTC + Kenko 2xTC

    You won;t know till you try.

    If the physical dimensions of where the lense elements protrude do not preclude stacking TCs, just give it a go since you already have both TCs!

    Stack the 2x behind the 1.5x.

    hope this helps.

  3. #3
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    Default Re: Tamron 1.4xTC + Kenko 2xTC

    Nothing is stopping you from doing that....but you may not get a better image than by just using the 500mm and cropping.

    Here's why:

    1. Assuming you 500mm has a maximum apertur of f/8. The effective aperture becomes f/22 when you stack it with the 2 converters.

    2. At that magnification level you have to limit your shutter speed to faster than 1/60 otherwise the motion of the moon itself will blur the image.

    3. 1 & 2 above mean that you will have to shoot at really high ISO setting, which increases the noise.

    4. AF will not work, and manual focusing will be difficult. Infinity lock does not mean anything. Even if you use manual focus, your focusing screen may not be perfectly aligned (in terms of optical track) with the sensor. i.e, what appears sharp on your screen may not be sharp on your sensor.

    5. You setup will be unstable. Tripod mounting on the camera is most likely out of the question, and even if you have a tripod nound on the lens, it will not be stable enough because the teleconverters will push the camera so far away. At close to 1500mm focal length you will notice every smallest bit of camera shake.

    Having said that I would still encourage you to give it a try, provided you already have the lens and the converters. I would not recommend spending money on getting a new lens and converters for this purpose.

    When you try it, find an alternative method of supporting your camera, like using a bean bag large enough to support the entire camera-lens assembly. Aiming will be more troublesome, but it is going to be more stable.

    Some other tips:
    1. Use timer or a cable release to minimize camera shake. If using timer set it to around 2 seconds, which will give enough time for the camera to stabilize and not too long such that you can take more shots in a given period of time.

    2. Use mirror lock up. On film SLRs and timer mode the mirror is always flipped when the timer starts running. On my D200 mirror lock up means I press the shutter release once to flip the mirror, then again to actually release the shutter.

    3. Bracket your exposures and bracket your focus. In focus bracketing I mean focus to as clear as you can, and then take multiple shots while moving the focus a tiny little bit at a time between shots. Later you can pick the sharpest shot out of the lot. This helps to sidestep the problem of focusing screen and sensor misalignment I mentioned above.

    4. Use on camera histogram to check and adjust exposure. Your metering will not be accurate. Spot metering might help.

    5. Use custom white balancing off the moon itself, if you are shooting JPEG. The moon should be white under normal conditions.

    6. Finally, and possibily most importantly, is to set your expectations appropriately. Be patient, and be prepared to take a lot of shots. Don't expect to be able to get decent shots at the first try and by taking only 2 or 3 shots.

    Good luck!
    As complexity rises, precise statements lose meaning and meaningful statements lose precision.

  4. #4
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    Default Re: Tamron 1.4xTC + Kenko 2xTC

    One more thing...to prevent neck strain use a 90-degree angle finder attachment.
    As complexity rises, precise statements lose meaning and meaningful statements lose precision.

  5. #5

    Default Re: Tamron 1.4xTC + Kenko 2xTC

    Quote Originally Posted by roygoh View Post
    One more thing...to prevent neck strain use a 90-degree angle finder attachment.
    thks, i will take note and give it a try... juz that i am afraid it will burn off my body circuitry doing the stack up... i think i am paranoid.. both the TC are generic so should not be a prob... actually i decided to do this cos i am running out of things to shoot with the 500mm at my neighbourhood..

    yeh.. i got my angle finder and remote also...
    Last edited by maximize; 15th November 2008 at 05:28 PM.

  6. #6
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    Default Re: Tamron 1.4xTC + Kenko 2xTC

    Hey, check out my thread Moon @ 2200mm

    I shot at an effective aperture of f/20, and it was challenging to say the least. I don't think the Alpha 200 has mirror-lockup, and neither does my Alpha 700. Even the neckstrap dangling from the camera was enough to cause image blur due to camera shake.

    Roygoh has basically covered all the salient points. And yes, finding and tracking the target is not easy. I used a ballhead, and even as I tightened the ballhead, that action was enough to shift the lens off target. At that magnification (when I shot with 1000mm +2x), the movement of the moon is pretty apparent and fast, so that would mean adjusting the camera every 30 seconds or so.

    Of course, image quality isn't going to be great, and with two TCs stacked, you're probably going to lose even more contrast and image resolution. The images that I've shown have actually been PP'ed. The original ones were kinda "muddy".

    Still, it's great fun and very satisfying when you manage to nail a good shot!
    Sony Alpha system user. www.pbase.com/synapseman

  7. #7

    Default Re: Tamron 1.4xTC + Kenko 2xTC

    Quote Originally Posted by synapseman View Post
    Hey, check out my thread Moon @ 2200mm

    I shot at an effective aperture of f/20, and it was challenging to say the least. I don't think the Alpha 200 has mirror-lockup, and neither does my Alpha 700. Even the neckstrap dangling from the camera was enough to cause image blur due to camera shake.

    Roygoh has basically covered all the salient points. And yes, finding and tracking the target is not easy. I used a ballhead, and even as I tightened the ballhead, that action was enough to shift the lens off target. At that magnification (when I shot with 1000mm +2x), the movement of the moon is pretty apparent and fast, so that would mean adjusting the camera every 30 seconds or so.

    Of course, image quality isn't going to be great, and with two TCs stacked, you're probably going to lose even more contrast and image resolution. The images that I've shown have actually been PP'ed. The original ones were kinda "muddy".

    Still, it's great fun and very satisfying when you manage to nail a good shot!

    yeh.. me juz wanna try to do some experiments with the lens thats all... part of the learning process... even at 500mm is rather shaky... too bad i dun have those veri good sturdy tripod.. i have a ball head type also... it somehow is worst than my $29 pan/tilt tripod... think the neck of the ball head is not strong and stable enough to keep it stable... in fact.. i find the shift was caused by mostly the wind... so i had to keep it really low... have to wait for the next full moon now.. ooooh... long wait... mean time i will try to optimize my setup and setting...

    yah.. i remembered i saw someone posted a thread on some moon shots.. was it you.. i couldnt remember but it was crisp sharp and beautiful.. i remembered i told myself when i have my 500mm i will give it a try...

    u have 1000mm with 2x... so i use 500mm with 2x and 1.4x... juz kidding.. i noe it will definitely degrade the quality veri much.. but juz wanna make sure my little experiments dun have to send in to SSC...

    but why f20? i did a sharpness test for my lens... its at f8...

  8. #8
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    Default Re: Tamron 1.4xTC + Kenko 2xTC

    As complexity rises, precise statements lose meaning and meaningful statements lose precision.

  9. #9

    Default Re: Tamron 1.4xTC + Kenko 2xTC

    Quote Originally Posted by roygoh View Post
    hey, awsome pics.. yah.. i wanna take something similar to replace the microsoft desktop moon pics for my wallpaper...

  10. #10
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    Default Re: Tamron 1.4xTC + Kenko 2xTC

    Quote Originally Posted by maximize View Post
    but why f20? i did a sharpness test for my lens... its at f8...
    The lens is a fixed aperture mirror lens at f/10. So with 2x tc, the effective aperture would be f/20
    Sony Alpha system user. www.pbase.com/synapseman

  11. #11

    Default Re: Tamron 1.4xTC + Kenko 2xTC

    Quote Originally Posted by synapseman View Post
    The lens is a fixed aperture mirror lens at f/10. So with 2x tc, the effective aperture would be f/20
    boleh.. understand liao.. kam sia...

    does that mean u still set the camera at f10, but effectively its f20.. or u set it at f20?
    Last edited by maximize; 18th November 2008 at 11:15 PM.

  12. #12
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    Default Re: Tamron 1.4xTC + Kenko 2xTC

    2x teleconverters cause a 2 stop loss in light reaching the sensor.

    Mirror lenses have fixed apertures. They are non-adjustable.
    Sony Alpha system user. www.pbase.com/synapseman

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