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03-30-2014, 08:54 AM   #1
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Sharpest aperture with a TC?

Hello, i have a question; lets say for example the sharpest f stop for the da*300 is f/5.6, if i add the new 1.4x TC, is f/5.6 still the sharpest aperture? or does it get better stoped down?
In other words, when adding a TC does a lense maintain its sharpest aperture ? (i know it looses its widest but i am not familiar with the technical details of how this happens though)

Thanks

03-30-2014, 09:13 AM   #2
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When you use a TC, it's effectively spreading the light from the lens out. The best aperture for edge sharpness no longer matters because the edges aren't hitting the sensor anymore. The best aperture for center sharpness should remain (so if the lens was at its center sharpness best at f4, it would be best at f4 on the lens which becomes effectively 5.6 with a 1.4tc.
03-30-2014, 09:39 AM   #3
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QuoteOriginally posted by narual Quote
When you use a TC, it's effectively spreading the light from the lens out. The best aperture for edge sharpness no longer matters because the edges aren't hitting the sensor anymore. The best aperture for center sharpness should remain (so if the lens was at its center sharpness best at f4, it would be best at f4 on the lens which becomes effectively 5.6 with a 1.4tc.
Ok, for using the real example i gave (i just bought the da*300, that should be here this week, that's why i care hehe), the best aperture remains 5.6 but it becomes 7.1? (with the new TC that passes the data correctly)

what about DOF, for example, the DOF of f4 that becomes 5.6 maintains? in other words, is everything affected when f4 becomes f5.6 or only the amount of light?

Thanks
03-31-2014, 01:18 AM   #4
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QuoteOriginally posted by carlosodze Quote
Ok, for using the real example i gave (i just bought the da*300, that should be here this week, that's why i care hehe), the best aperture remains 5.6 but it becomes 7.1? (with the new TC that passes the data correctly)

what about DOF, for example, the DOF of f4 that becomes 5.6 maintains? in other words, is everything affected when f4 becomes f5.6 or only the amount of light?

Thanks
It would be great if someone can answer that too. My x1.4 just arrived, but at work right now, don't have the space or time to test. I only did a few shot with my 50-135 + x1.4. I think (please correct me if I am wrong) the DOF remains the same, just the light are spread out. So F4 should look the same @5.6 after the x1.4, just "lower" amount of light is reaching the sensor.

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