Photos taken by a Pentax camera for tech. discussion - Season 0

[tabako]

Oh yah, not the Pro 300 series... is it better than the older models?

Don't quite like the idea of taping the pins, since tape can come off over time and leave sticky residue. The teleconverter is actually quite easy to take apart and re-assemble, the lens assembly is mounted together as one solid piece so it's quite safe. Just takes a bit of time and patience working with all those tiny springs and pins... ;(

I just gotten the Pro 300 DG 1.4x from DDelectronics for $144 after 2% cash discount. Freaking cheap. Anyway I tested a bit.

IQ is very good, only very slight degration and if you dun pixel peep, its not noticable. It reports its presense to my camera, so I have accurate EXIF data, f4 -> f5.6 and 200mm ->280mm. Even the lens used in the EXIF will show 70-200mm + 1.4x.

Autofocus is very still very fast, only slower by a bit. Of cos in good light, in low light, even without 1.4x also will hunt. But of cos I have USM motor, after using 1.4x it is still a lot faster than sigma, tamron lens. So if you use it on 3rd party lens without a fast AF motor on the lens, be prepared that it will be very slow.

I have not used the old one, but if old one has bad IQ, then this new one will be better. Because all the website and online review rates it as good as original Canon EF extender 1.4x II.

 

[kengoh]

I didn't know 200mm is long enough for birds. I have 200mm, except bird park where in Singapore can I shoot bird with 200mm?

Depends on how far the bird is.
This shot was taken with 300mm & it's still not enuff reach.

Until the bird flew to a tree nearer & after I cropped:

I'm looking for longer zoom lens/solution. :sweat:

 

[pinholecam]

I'm looking for longer zoom lens/solution. :sweat:

This is a clear shot

The cheapest long lens solution with AF, Auto Aperture, will be a Bigma.

 

[Gengh]

I just gotten the Pro 300 DG 1.4x from DDelectronics for $144 after 2% cash discount. Freaking cheap. Anyway I tested a bit.

IQ is very good, only very slight degration and if you dun pixel peep, its not noticable. It reports its presense to my camera, so I have accurate EXIF data, f4 -> f5.6 and 200mm ->280mm. Even the lens used in the EXIF will show 70-200mm + 1.4x.

Autofocus is very still very fast, only slower by a bit. Of cos in good light, in low light, even without 1.4x also will hunt. But of cos I have USM motor, after using 1.4x it is still a lot faster than sigma, tamron lens. So if you use it on 3rd party lens without a fast AF motor on the lens, be prepared that it will be very slow.

I have not used the old one, but if old one has bad IQ, then this new one will be better. Because all the website and online review rates it as good as original Canon EF extender 1.4x II.

My Kenko 1.5x is also pretty decent, IQ acceptable when paired with a good lens. But when paired with the Tamron 70-300mm at the long end it was a disaster... :sweat: Exif is also not indicated correctly, there's no electronics inside so it can't change the info that the lens feeds to the body. Wonder if Kenko will eventually make the 300 pro series for other mounts including Pentax. :think:

 

[kesha]

Hi Nik3a, I just back from Singapore, I got my K7 from CS's friend, many thank to him (will post K7 shots later).

Shot this images at ViVo City, used K10D + Hoya 200mm/F3.5:

 

[ohok1973]

My Kenko 1.5x is also pretty decent, IQ acceptable when paired with a good lens. But when paired with the Tamron 70-300mm at the long end it was a disaster... :sweat: Exif is also not indicated correctly, there's no electronics inside so it can't change the info that the lens feeds to the body. Wonder if Kenko will eventually make the 300 pro series for other mounts including Pentax. :think:

At the long end, is it still auto focus or manual, am thinking of getting a 1.4x teleconvertor too.

 

[darrrrrrrrrr]

A very short shoot today with a welding glass filter and step-up ring I ordered from eBay. Shade 10 = 14 stop ND filter for only S$13.

I'll have to experiment more to get rid of color casts, vignetting and serious flaring since this is hardly optical quality glass.

40s

120s

 

[Gengh]

At the long end, is it still auto focus or manual, am thinking of getting a 1.4x teleconvertor too.

You mean using a 1.4x teleconverter with a 300mm f5.6 lens on the long end? I've only used this combo in fairly bright conditions (overcast but bright day), and the AF still worked fine. But that's just my experience, technically, it's probably pushing the limits of the AF sensors.

 

[ranchy]

A very short shoot today with a welding glass filter and step-up ring I ordered from eBay. Shade 10 = 14 stop ND filter for only S$13.

I'll have to experiment more to get rid of color casts, vignetting and serious flaring since this is hardly optical quality glass.

40s

120s

Woot i like the effects.. U took it during the day time? noon or evening? 120s exposure.. Ur ND filter is working. :bsmilie:

 

[kesha]

Yeah, I really like the effect, Darrenn.
120s?

 

[tabako]

You mean using a 1.4x teleconverter with a 300mm f5.6 lens on the long end? I've only used this combo in fairly bright conditions (overcast but bright day), and the AF still worked fine. But that's just my experience, technically, it's probably pushing the limits of the AF sensors.

Won't the 1.4x pushed the aperture to f8? Pentax can AF with f8? cool, cos lower end Canon can only AF with f5.6, there are electronics contact on teleconverter that tell the camera body that it is f8, and Canon just auto shut off AF, it won't even attempt to try and AF.

Not unless you buy 1D series body which can AF at f8.

 

[darrrrrrrrrr]

Woot i like the effects.. U took it during the day time? noon or evening? 120s exposure.. Ur ND filter is working. :bsmilie:

It was taken at around 2pm so it was broad daylight. Normal shutter speed was around 1/500s, f8, ISO 100. Yup the "ND filter" definitely works!

 

[ohok1973]

You mean using a 1.4x teleconverter with a 300mm f5.6 lens on the long end? I've only used this combo in fairly bright conditions (overcast but bright day), and the AF still worked fine. But that's just my experience, technically, it's probably pushing the limits of the AF sensors.

am thinking of using it with a tamron af18-250mm. the long end will be 6.3 for this lens, that rounds up to abt 8.9(1.4x) with the convertor.

Wonder if it will work, i knows it doesnt work with a 2x convertor

 

[tabako]

am thinking of using it with a tamron af18-250mm. the long end will be 6.3 for this lens, that rounds up to abt 8.9(1.4x) with the convertor.

Wonder if it will work, i knows it doesnt work with a 2x convertor

It does not work that way with aperture, it pushes 1 stop. so from f4 -> f5.6, f5.6 -> f8, f8 -> f11 etc. 2x teleconverter will push 2 stops for aperture.

So you are actually looking at f9. Works or not depend on your camera body, every model has a different AF limit. Mine does not work with more than f5.6 to AF.

Actually I calculated, 1 stop is more or less x 1.4.
From wiki: The photography term "one f-stop" refers to a factor of √2 (approx. 1.41) change in f-number, which in turn corresponds to a factor of 2 change in light intensity.

 

[ohok1973]

It does not work that way with aperture, it pushes 1 stop. so from f4 -> f5.6, f5.6 -> f8, f8 -> f11 etc. 2x teleconverter will push 2 stops for aperture.

So you are actually looking at f9. Works or not depend on your camera body, every model has a different AF limit. Mine does not work with more than f5.6 to AF.

Actually I calculated, 1 stop is more or less x 1.4.
From wiki: The photography term "one f-stop" refers to a factor of √2 (approx. 1.41) change in f-number, which in turn corresponds to a factor of 2 change in light intensity.

so what is the limit for KX? been surfing the web with no results...

 

[gigahz]

Benchmark for K7d + 70mm 2.4

 

[felixcat8888]

Benchmark for K7d + 70mm 2.4

Beautifully captured :thumbsup:

 

[Gengh]

Won't the 1.4x pushed the aperture to f8? Pentax can AF with f8? cool, cos lower end Canon can only AF with f5.6, there are electronics contact on teleconverter that tell the camera body that it is f8, and Canon just auto shut off AF, it won't even attempt to try and AF.

Not unless you buy 1D series body which can AF at f8.

Effective max aperture is indeed f8, but I guess since the teleconverter doesn't tell the body that, the body still works thinking it's f5.6. And since there's enough light, it'll just try its best.

I actually didn't know that the bodies are designed to cut off AF once you mount something with small max aperture sizes on, I thought they'll just struggle and fail to lock AF.

ohok1973, f6.3 with 1.4x might really be pushing it, I'm not sure if it'll work. Maybe if your scene is a nice daylight scene it'll still be ok. You can't use a 300+mm f9 equivalent lens in any dim condition anyway right?

 

[tabako]

Effective max aperture is indeed f8, but I guess since the teleconverter doesn't tell the body that, the body still works thinking it's f5.6. And since there's enough light, it'll just try its best.

I actually didn't know that the bodies are designed to cut off AF once you mount something with small max aperture sizes on, I thought they'll just struggle and fail to lock AF.

ohok1973, f6.3 with 1.4x might really be pushing it, I'm not sure if it'll work. Maybe if your scene is a nice daylight scene it'll still be ok. You can't use a 300+mm f9 equivalent lens in any dim condition anyway right?

Oh the teleconverter doesn't tell the body, no wonder. But in this case, EXIF will not report true aperture.

Actually my kenko if i tape the pins, so that it won't tell the camera also can mount slower lens. But I only have f4 lenses now, so I'll try next time.

 

[darrrrrrrrrr]

Not the best of skies, but you get the idea.

1/500

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