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09-07-2010, 09:28 PM   #16
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As was yours :-)

09-08-2010, 05:40 AM   #17
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QuoteOriginally posted by Marc Sabatella Quote
- We don't actually know if that shot would have come out better or worse without the TC by simply cropping - that's the usual sense in which TC's are said to be counterproductive.
I am very sorry about the horrific condition of the test board, but it was raining cats and dogs here yesterday and I only had a small window of opportunity to run some trials. So it is what it is...


Without TC, 300mm, f/8, 170% CROP



With TC(1.7x), 510mm, f/8, 100% CROP




QuoteQuote:
It may also be the case that the specific lens in question does work better with TC's than most modern consumer zooms.
I'm honestly thinking we struck gold here! In fact... CA and PF even improve with TC than without it.

QuoteQuote:
There is still the issue of loss of light (and the effect of this on AF where relevant) to consider in evaluating the extent to which it makes sense to use a TC.
Definitely the biggest bummer of this combo. The lens sits most comfortably at f/8 which already makes it rather slow in many circumstances, but once the TC is attached, it takes a considerable hit in speed.


I'm going to give this setup another go over the weekend when(hopefully) the weather improves.

Last edited by JohnBee; 09-08-2010 at 05:51 AM.
09-08-2010, 07:48 AM   #18
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The crops do tell a good story here - that's better than I've seen with modern consumer zooms. Not that I've seen the 1.7x AF TC in particular with any of them. But no matter how you slice it, it does look like a great combo.
09-08-2010, 07:53 AM   #19
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Thanks for the answer that was very informative. I had considered the quality issue and was thinking along the same lines. I grew up in N. Va and went to college at VCU! Nadine

09-08-2010, 08:01 AM   #20
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Thanks for the help! Your test was great and I would find that combo perfectly acceptable the only issue I have is if your converter would be compatible with the Sigma DG lens I was thinking of using that with.
09-08-2010, 08:04 AM   #21
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Please forgive this newbie! I will be more careful in future.
Nadine
09-08-2010, 08:11 AM   #22
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QuoteOriginally posted by NMercader Quote
Thanks for the help! Your test was great and I would find that combo perfectly acceptable the only issue I have is if your converter would be compatible with the Sigma DG lens I was thinking of using that with.
I believe Sigma makes an excellent 1.4x TC

TBH. I would lean toward matching your lens with a TC of same brand so as to get the most out of your setup. I've been running some quick trials here with other 300mm lenses I own and I do believe the combination I posted here is a unique circumstance. So I wouldn't want to mislead you into thinking you might achieve similar results with another lens/TC combination.

On a brighter note, I have a bit of time off this afternoon and the sun has come out again.
I'm going to nail a new resolution chart to the board and run some more tests
09-08-2010, 11:01 AM   #23
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I snagged this handheld during lunch today. It was ISO1600 and underexposed(didn't get a chance to adjust anything) so there is detail loss. Having said that, I printed out some new high res. resolution charts today and so I'll be doing some more testing with those tomorrow afternoon. Aside from the bird, I really like the way it's handing OOF details such as branches etc. These are the area's that usually come up as problematic.


K20D, ISO1600, 1/240s, 510mm, f/5.6

I have another image I'll post next where I tested CA/PF in strong backlighting. Though I'll say ahead of time, the combo performed admirably. This is the only Lens/TC combination I've ever seen where CA is reduced.


Last edited by JohnBee; 09-08-2010 at 11:46 AM.
09-08-2010, 12:24 PM   #24
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QuoteOriginally posted by JohnBee Quote
I am very sorry about the horrific condition of the test board, but it was raining cats and dogs here yesterday and I only had a small window of opportunity to run some trials. So it is what it is...


Without TC, 300mm, f/8, 170% CROP



With TC(1.7x), 510mm, f/8, 100% CROP




I'm honestly thinking we struck gold here! In fact... CA and PF even improve with TC than without it.

Definitely the biggest bummer of this combo. The lens sits most comfortably at f/8 which already makes it rather slow in many circumstances, but once the TC is attached, it takes a considerable hit in speed.


I'm going to give this setup another go over the weekend when(hopefully) the weather improves.
John,
Same thing happened to me a while back, using this TC (adapter) with my DA*300/4: the pics "seemed" sharper!
I though at first it was because I was more careful taking the shots than without the TC attached? Read: less sloppy technique.
But then I saw this post of yours!
Happy to see that I wasn't dreaming.

JP
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