Loyal Site Supporter Registered: October, 2018 Location: Quebec City, Quebec Posts: 6,493 2 users found this helpful | Review Date: July 18, 2020 | Recommended | Price: $100.00
| Rating: 10 |
Pros: | Just a little degradation of prime lens sharpness, very light. | Cons: | None except it doesn't fit all lenses. | | Picture taken with an FA 200 mm f/4 telephoto + 1.4X TC, 1600 ISO, 1/500 sec @ f/9 handheld. Picture taken with an FA 200 mm f/4 telephoto + 1.4X TC, 200 ISO, 1/125 sec @ f/11 on a tripod. Picture taken with an FA 200 mm f/4 telephoto + 1.4X TC, 200 ISO, 1/40 sec @ f/16 on a tripod. | |
Pentaxian Registered: January, 2009 Location: East Bay Area, CA Posts: 6,611 3 users found this helpful | Review Date: June 20, 2019 | Recommended | Price: $230.00
| Rating: 9 |
Pros: | IQ is good, compact size | Cons: | none | | This is a very capable 1.4x TC for several 645 lenses. I use mine specifically with the A*600/5.6 when I need to fill the frame beyond the minimum FoV of the lens itself. For this purpose, it is slightly better to add the TC than it is to crop and size up the 600mm image.
Here is a sample comparison: | |
Site Supporter Registered: February, 2018 Location: NoVA Posts: 635 4 users found this helpful | Review Date: May 22, 2018 | Recommended | Price: $90.00
| Rating: 9 |
Pros: | Does what it's supposed to do with very little case space invasion | Cons: | It's effects are visible at high magnification, but maybe not important most of the time. | | The real question is: Should one use a teleconverter, or merely crop the photo from the shorter lens?
Here is a 1:1 center crop from an image made with a 645 A* 300/4, at f/11:
And here is a crop from an image made with the 1.4 converter, downsampled to the same resolution as the image above:
No question: Downsampling the longer lens combination is not better than using the shorter lens. But considering these crops (at least the first one) is part of a 7-foot-wide print viewed at 100 pixels/inch, they are both really good. I'd use the 1.4 when I needed all fifty million of my pixels, but otherwise the A* 300 just has nowhere to go but down. It didn't go very far down here, but the converter still degraded the image more than enlargment.
Another question is whether a shorter lens plus a converter is better than carrying both the shorter and the longer lens.
Here is a 1:1 crop made using the 400/5.6 ED(IF), at f/11:
And here is a crop at 1:1 (without downsampling) from the 300+1.4 at f/11:
Not much difference here, but I would say that the 400 looks a bit better. Clearly, the A* 300 is a (slightly) better lens, but the 400 is worth bringing if one needs to optimize for that focal length.
So, the advice is: If you use the 1.4, start with a great lens. Stop it down a bit, and then don't worry about it. The converter has visible effects at high magnification, but it is still a very capable teleconverter.
Rick "always room for a converter" Denney
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Loyal Site Supporter Registered: November, 2011 Location: pontiac mi. Posts: 392 1 user found this helpful | Review Date: June 28, 2015 | Recommended
| Rating: 9 |
Pros: | light, easy hookup, | Cons: | manual focus only. | | so sharp you can see individual hairs on the arm, no loss of IQ that I can see. the fact that Pentax sells it says that it has to be good.
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Site Supporter Registered: November, 2008 Location: Washington DC, USA Posts: 632 3 users found this helpful | Review Date: November 6, 2010 | Recommended | Price: $200.00
| Rating: 9 |
| This is a nice little converter. It works with more than just the A 300mm f/4. I have used this with my Pentax FA 400mm f/5.6 and the FA 120mm f/4 macro.
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