Pentax 150-450mm
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver
Did you manage to test the AF speed with the 1.4X John ?
Sorry no, it was a poor day really. I will try locally tomorrow and make a point of doing this and get back to you.
My outfit: K1ii - Pentax D FA 24-70mm f2.8 - Pentax DA* 300mm f4 - Pentax modified DA* 60-250mm f4 - Irix 15mm Firefly - Pentax FA 35mm - FA 50mm f1.4 - Tamron SP 90mm macro - Pentax AF 540 FGZ II
Welsh Photographer
Flickr
My PPG
Foundation NFT
Did you manage to test the AF speed with the 1.4X John ?
Sorry no, it was a poor day really. I will try locally tomorrow and make a point of doing this and get back to you.
Subjectively, it didn't seem to make a lot of difference, so I ran a test using an online stopwatch. Obviously it depends on how far the lens has to focus as to how long it will take, but with identical parameters we can establish the difference between speed with and without the converter.
Each shot was started at an aim point on the display, after which the lens was defocused the same amount every time ready for the next aim point. The aim point is irrelevant, but it was 5 second intervals. The delay was observed by seeing what the display on the shots taken was. This includes any operator variation, but that too will even out after a lot of shots.
Without the converter, the delay between the shutter release being pressed, the lens focusing and the shot being taken varied from 0.2s to 0.4s and averaged out at 0.3s
With the converter, the delay varied between 0.2s and 0.4s and averaged out at 0.3s
In summary, the converter made no difference whatsoever, Hope that helps, I'll post more into on the lens as I use it more.
Dave
Unfortunately Dave I don't have the 300mm, otherwise I'd be happy to try it out.
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That's a shame. I think the majority of birding and wildlife Pentax users will look at this and ask themselves two questions. Compared to the DA*300+ 1.4x TC how fast does it focus at 420mm and how does the image quality compare.
Dave
Unfortunately Dave I don't have the 300mm, otherwise I'd be happy to try it out.
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That's a shame. I think the majority of birding and wildlife Pentax users will look at this and ask themselves two questions. Compared to the DA*300+ 1.4x TC how fast does it focus at 420mm and how does the image quality compare.
Dave
Found this odd though:-
"...keeper rate rate is much higher with this lens then with the da*300 (+tc) and it feels like you have a higher buffer/burst rate. High iso looks cleaner as well comparing it with the da*300+tc"
Why? Surely these are camera/sensor issues not lenses?
Dave
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24265 posts
22 years
Tyldesley,
Manchester
In summary, it's a great lens, sharp, heavy, and the bokeh is sublime.
I've no doubt practice with it and better light will give better images yet, but so far it's very pleasing.