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12-08-2009, 09:40 PM   #1
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TEST: Stacking MULTIPLE 2X Teleconverters

Hey Guys, I just picked up 3 beaten-but-still-usable teleconverters tonight off craigslist for $35. I Dont know if you guys would be able to rank the quality of those TC for me (I'd be happy if anyone can!), bu I did some funny things with the TC -- thats right! STACKING THEM TOGETHER! (Or else why the heck you think I bought 3 at once?)

To my knowledge nobody here had done that on this forum. So I might as well be the first one to play around.

Below are all the TCs:



Test:
With the lens at 210mm, the 3 TCs will make the lens into 1680mm. Given min apreature will become f44.8. What a scary number eh?
Becasue it is late at night here in Toronto, I couldnt do much testing. I only take a few shot around my room just to see how the image will turn out (and prove if it is useful at night)

Equipment, in the order of attachment:
1. Pentax K-x
2. Makinon No.1 2X TC
3. Osawa RC4 TC
4. Tamaron MC 2X TC
5. Kiron 28-210 4-5.6 MF Zoom

Procedures:
1. Kiron lens was set on 210mm, f5.6 when all the photo were taken.
2. All TC are cleaned to ensure they are clear
3. All the photo were taken without any supporting device, IE: they are all taken hand-held.
4. Focus accuracy could not be guaranteed as it is really really really dark via viewfinder.

Observation:
0. Photo still shows up even tho the Apature is @ 44.8!
1. But the photos look like shit. Seriously. Useful perhaps only if you can justify the loss of quality.
2. Pentax's SR works.
3. given that the Kiron 28-210 is not the best zoom, things could change if i use other lens.
4. Order of TC could play a role on how the image quality turn out
5. Tamaron's TC is scratched on front element
6. there are permenant and inevitable specks that shows on the photos due to the poor TC conditions.


Followed By image taken:
1. full size
2. Further cropped













And this is the original Image @ 28mm.




Shall I run more test? If so what should I take?


Last edited by AMBIVALENCE; 12-08-2009 at 10:20 PM. Reason: Photo resize
12-09-2009, 04:26 AM   #2
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Set focus to infinity ... get a tripod ... and shoot the moon if you can ... although i think the really slow shutter speed will cause blur movement as the moon is always on the move.
12-09-2009, 09:35 AM   #3
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Any kind of indoor tests with this would be in vain -- think of how thin the DOF is. Also, you might get sharper results with a smaller aperture on the lens, though that would result in a miniscule actual aperture! Loan two tripods from somewhere (one for the lens and one for the camera!) and try out some extremely long exposures

BTW, with that kind of setup, just setting the lens to infinity focus might not be accurate. Focusing properly might be impossible.
12-09-2009, 12:10 PM   #4
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Gosh I remember trying that once. I just ended up buying longer lenses

12-09-2009, 02:40 PM   #5
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Original Poster
QuoteOriginally posted by FotoPete Quote
Gosh I remember trying that once. I just ended up buying longer lenses
Yeah! but i can still see myself attaching 3 TCs on a 500mm. I dont know why, It's just something I would do...
12-09-2009, 02:50 PM   #6
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Hey, if you've got them you might as well use them!
12-09-2009, 09:43 PM   #7
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QuoteOriginally posted by Spyder Quote
Hey, if you've got them you might as well use them!
Who doesnt want a 6000mm lens? Or 12000mm lens to be more precise (1000mm pentax)
12-09-2009, 10:13 PM   #8
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QuoteOriginally posted by AMBIVALENCE Quote
Who doesnt want a 6000mm lens? Or 12000mm lens to be more precise (1000mm pentax)
Wouldn't a 500 turn into a 4000mm with 3 2x teleconverters?

And wouldn't a 1000 turn into an 8000?

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