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05-22-2008, 02:03 PM   #1
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DA*200mm +1.5TC Vs A*300mmF4

One thing I have noticed is that Kenko 1.5X works flawlessly with DA200mm in both AF and the quiet operation of the in lens motor.

I have chosen the DA*200mm at F4 plus the 1.5Kenko TC compared with A*300mm at F6.5. I believe they are on level field now at least in terms of F stop. Here is the close up which is self-explanatory. All were taken with support and 2 s delay shutter to reduce camera shake to the minimum







200mm plus Kenko 1.5x












200mm plus Kenko 1.5x










Daniel, Toronto
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05-22-2008, 02:37 PM   #2
Syb
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So... are you selling your 200SDM?

:-)

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05-22-2008, 03:10 PM   #3
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QuoteOriginally posted by Syb Quote
So... are you selling your 200SDM?

:-)

Syb
I would not mind bringing over to EU and selling that with a tidy profit as I believe it is quite pricey there in the region of US$1400 compared with the US price of around 1000.

My wife loves the travel plan or preretirement orientation somewhere in EU.

Daniel, Toronto
05-22-2008, 07:17 PM   #4
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DA200mm wide open with 1.5TC which is equivalent to F6.5

Daniel

05-22-2008, 08:01 PM   #5
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Do you happen to have a 200 shot without the TC? If so, could you blow it up 1.5x and compare to the 300 please?

It is quite obvious that the TC damages the IQ.

Also, when you say that the 200 was shot at F4, does that have an converted aperture approximating the F6.3 used for the 300?
05-22-2008, 08:46 PM   #6
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Daniel, I'm a little confused by your methodology for this test. The DA*200 f/2.8 + the Kenko 1.5 TC becomes a 300mm f/4 (well, f/4 and a smidge, but near enough). To do an apples to apples test, the A* 300 f/4 should be shot wide open as well, or at least test both lenses at the same aperture(s). As it is now, you're comparing one lens coupled with a TC wide open, to another lens with no TC stopped down 1.3 stops.
05-23-2008, 12:53 AM   #7
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QuoteOriginally posted by Groundloop Quote
Daniel, I'm a little confused by your methodology for this test. The DA*200 f/2.8 + the Kenko 1.5 TC becomes a 300mm f/4 (well, f/4 and a smidge, but near enough). To do an apples to apples test, the A* 300 f/4 should be shot wide open as well, or at least test both lenses at the same aperture(s). As it is now, you're comparing one lens coupled with a TC wide open, to another lens with no TC stopped down 1.3 stops.

The DA*200mm at F4 is not wide open. See my earlier test and inquieries from dpreview

My apology to all; New comparison images : Pentax SLR Talk Forum: Digital Photography Review

I did what you said a week ago and compared the two both at F4.5 . That ended up very much one side in favour of the da200mm+tc combo because of the aperture advantage. The whole dpreview thread is self explanatory

Daniel, Toronto
05-23-2008, 05:34 AM   #8
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Thanks for sharing this with us.

From another test here in the forum using the DA*300 + 1.4xTC / 2xTC I concluded that DA* 300 had to be stopped down 1 stop for 1.4xTC (f/5.6) and 2 stops for 2xTC (f/8) to achieve full resolution.

Therefore, I would be interested to see a comparison with the 200mm at f/5.6 or smaller as well. Then of course, the first sample has defocus (otherwise, the corners wouldn't be sharper than the centre). And I would like to see an upsampled 200mm w/o TC as well, as another poster already suggested.

EDIT. Just had a look at DPR. Your findings aren't quite in line with some K20D's DA*/TC findings which is more demanding resolution-wise anyway. Therefore I am wondering what you did to ensure that you got accurate focus with the TC? Did you try a manual focus bracketing?


Last edited by falconeye; 05-23-2008 at 05:41 AM.
05-23-2008, 01:37 PM   #9
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QuoteOriginally posted by Aegon Quote
Do you happen to have a 200 shot without the TC? If so, could you blow it up 1.5x and compare to the 300 please?

It is quite obvious that the TC damages the IQ.
I am no expert. Any suggestion as to how to blow up 1.5X ? I get confused easily. It would be a good test of the two * lenses.
QuoteQuote:
Also, when you say that the 200 was shot at F4, does that have an converted aperture approximating the F6.3 used for the 300?
Yes. About F6.5 which is why I shot the A*300mm at F6.3 for comparison

Daniel
05-24-2008, 03:19 AM   #10
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One issue about the Kenko TC 1.4 & 1.5 and 2x. Because it does not reflect its presence, the SR will only work partially.
It is a AF combo and the SR is auto set to 200mm . But in fact it should have SR catered for 300mm.
Pentax 1.7x does reflect the true FL for the SR to work though

Daniel
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