DA*55 and 1.4xTC

Sandy Hancock · 05-29-2014, 06:21 PM

I plan to use my newish HD DA 1.4x AW AF rear converter as my "Single In" lens for June, and have just tried it out on my DA*55. Interestingly, the maximum aperture I can set to the lens to is f/2.4, which is half a stop smaller than expected.

Does anyone know why this would be the case? With my DA*300 and DA*50-135 the maximum apertures are f/5.6 and f/4.0 respectively as expected.

Uluru · 05-29-2014, 06:24 PM

Originally posted by Sandy Hancock

I plan to use my newish HD DA 1.4x AW AF rear converter as my "Single In" lens for June, and have just tried it out on my DA*55. Interestingly, the maximum aperture I can set to the lens to is f/2.4, which is half a stop smaller than expected.

Does anyone know why this would be the case? With my DA*300 and DA*50-135 the maximum apertures are f/5.6 and f/4.0 respectively as expected.

Perhaps to ensure perfect accuracy of the focus. It may be a work in progress, though, and in future some firmware update may change it to f2.

Adam · 05-29-2014, 06:33 PM

Originally posted by Sandy Hancock

I plan to use my newish HD DA 1.4x AW AF rear converter as my "Single In" lens for June, and have just tried it out on my DA*55. Interestingly, the maximum aperture I can set to the lens to is f/2.4, which is half a stop smaller than expected.

Does anyone know why this would be the case? With my DA*300 and DA*50-135 the maximum apertures are f/5.6 and f/4.0 respectively as expected.

It seems that other AF lenses with F1.4 are also limited to F2.4 with the teleconverter (we tested the F and FA 50mm F1.4 in our in-depth review). This is obviously being forced through firmware, but the reasons for it are unknown. Perhaps to keep image quality to high standards...

DSims · 05-29-2014, 06:41 PM

Originally posted by Adam

t seems that other AF lenses with F1.4 are also limited to F2.4 with the teleconverter (we tested the F and FA 50mm F1.4 in our in-depth review). This is obviously being forced through firmware, but the reasons for it are unknown. Perhaps to keep image quality to high standards...

And this would make sense on the F or FA, but not necessarily on the DA*. Too bad if that's the reason.

Uluru · 05-29-2014, 07:23 PM

Originally posted by DSims

And this would make sense on the F or FA, but not necessarily on the DA*. Too bad if that's the reason.

In this case, DA*55 is indeed a 35mm capable lens.

DSims · 05-29-2014, 07:28 PM

Originally posted by Uluru

In this case, DA*55 is indeed a 35mm capable lens.

I'm not sure why you mentioned this; I was referring to the fact that the F and FA 50/1.4 need to be stopped down much more than the DA*55 does if you want high IQ.

Adam · 05-29-2014, 07:32 PM

Originally posted by DSims

I'm not sure why you mentioned this; I was referring to the fact that the F and FA 50/1.4 need to be stopped down much more than the DA*55 does if you want high IQ.

But the teleconverter amplifies imperfections in the lens, and wide-open they'd probably be quite easy to spot.

Look at the bright side: many high-end teleconverters from other brands (like Nikon) won't even fit on a 55mm; they require tele lenses.

Adam
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Sandy Hancock · 05-29-2014, 07:53 PM

Rather dreamy at f/2.4

Brutally sharp at f/5.6

DSims · 05-29-2014, 07:54 PM

Originally posted by Adam

But the teleconverter amplifies imperfections in the lens, and wide-open they'd probably be quite easy to spot.

Look at the bright side: many high-end teleconverters from other brands (like Nikon) won't even fit on a 55mm; they require tele lenses.

True, I guess even on the DA*55 it might be easy to recognize the imperfections if it were able to use wider apertures.

---------- Post added 05-29-14 at 07:57 PM ----------

Originally posted by Sandy Hancock

Rather dreamy at f/2.4

Brutally sharp at f/5.6

Whadayaknow: It looks like proof arrived as I was typing!

VisualDarkness · 05-30-2014, 03:44 AM

Still I think it's a bad choice to limit it like that, it doesn't hurt really to have the option even though the quality may suck bad. I guess they just played it safe.

pid · 05-30-2014, 07:08 AM

I think it has to do with the smaller diameter of the Lenssystem of the converter. There would be to much light reflection between lens and Converter. The "dreamy effect" will occur with all f-stops bellow f2.8. In Low Light situation you will get better results below f2.8 as in sunlight with hard contrasts. I tested it with all three FA Limiteds and the DA*55 with the same results. The "dreamy effect" disapears behind f2.8 in combination with the Converter this will be f4.0.

Uluru · 06-02-2014, 08:43 PM

Originally posted by VisualDarkness

Still I think it's a bad choice to limit it like that, it doesn't hurt really to have the option even though the quality may suck bad. I guess they just played it safe.

We can only imagine a number of bad reviews and deliberately evil remarks about the quality of the TC if they allowed it. Because people would not understand physical barriers.
There are some physical limits to everything, and a TC is not a substitute for a dedicated lens design. TC is a complementary tool, used with consideration and care, mostly for telephoto lenses at moderately wide apertures (f2.8 – f/4). So I'd say, a DA100WR should be a staring point of some meaningful use. DA*200, DA*300 are the lenses TC can be used with success, and DA*60-250 being one almost pointless to be used with a TC. Of them all, DA*300 should be the most popular, natural choice.

I can't even understand why are people using a TC with a DA*55 lens, or, on the other hand, 18-135/3.5-5.6 zoom and kit lenses.

VisualDarkness · 06-02-2014, 09:02 PM

Me neither. You can even get longer lenses used for the same price or less than the converter, still people even want it for the 18-135 or even 18-55.
I just dislike limitations like that even though I understand the reasoning behind them.

Sandy Hancock · 06-02-2014, 09:32 PM

I satisfactorily explained in my original post why I used the DA*55 with the converter. Any other time I would of course use my FA77, or crop a shot with the DA*55 mounted directly.

I just thought it was interesting

zbrueningsen · 06-19-2014, 04:25 AM

UluEU, have you used the DA 55 before? I really wanted an 85mm lens but didn't want to shell out what the FA 85 cost. So a 1.4 teleconverter was The idea. For me doing portraits is why. It isn't that we want a telephoto lens, but the DA 55 is simply a masterpiece of optics.

05-29-2014, 06:21 PM	#1
Sandy Hancock Moderator Site Supporter Join Date: Feb 2012 Location: Adelaide Hills, South Australia Photos: Gallery \| Albums Posts: 11,275	*DA55 and 1.4xTC** I plan to use my newish HD DA 1.4x AW AF rear converter as my "Single In" lens for June, and have just tried it out on my DA55. Interestingly, the maximum aperture I can set to the lens to is f/2.4, which is half a stop smaller than expected. Does anyone know why this would be the case? With my DA300 and DA*50-135 the maximum apertures are f/5.6 and f/4.0 respectively as expected.

05-29-2014, 06:33 PM	#3
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,608	Originally posted by Sandy Hancock I plan to use my newish HD DA 1.4x AW AF rear converter as my "Single In" lens for June, and have just tried it out on my DA55. Interestingly, the maximum aperture I can set to the lens to is f/2.4, which is half a stop smaller than expected. Does anyone know why this would be the case? With my DA300 and DA50-135 the maximum apertures are f/5.6 and f/4.0 respectively as expected. It seems that other AF lenses with F1.4 are also limited to F2.4 with the teleconverter (we tested the F and FA 50mm F1.4 in our in-depth review). This is obviously being forced through firmware, but the reasons for it are unknown. Perhaps to keep image quality to high standards... Adam* PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

06-02-2014, 08:43 PM	#12
Uluru Banned Join Date: May 2010 Location: Back to my Walkabout Creek Photos: Gallery \| Albums Posts: 2,535	Originally posted by VisualDarkness Still I think it's a bad choice to limit it like that, it doesn't hurt really to have the option even though the quality may suck bad. I guess they just played it safe. We can only imagine a number of bad reviews and deliberately evil remarks about the quality of the TC if they allowed it. Because people would not understand physical barriers. There are some physical limits to everything, and a TC is not a substitute for a dedicated lens design. TC is a complementary tool, used with consideration and care, mostly for telephoto lenses at moderately wide apertures (f2.8 – f/4). So I'd say, a DA100WR should be a staring point of some meaningful use. DA200, DA300 are the lenses TC can be used with success, and DA60-250 being one almost pointless to be used with a TC. Of them all, DA300 should be the most popular, natural choice. I can't even understand why are people using a TC with a DA55 lens, or, on the other hand, 18-135/3.5-5.6 zoom and kit lenses. Last edited by Uluru; 06-02-2014 at 08:50 PM.*

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05-29-2014, 06:24 PM	#2
Uluru Banned Join Date: May 2010 Location: Back to my Walkabout Creek Photos: Gallery \| Albums Posts: 2,535	Originally posted by Sandy Hancock I plan to use my newish HD DA 1.4x AW AF rear converter as my "Single In" lens for June, and have just tried it out on my DA55. Interestingly, the maximum aperture I can set to the lens to is f/2.4, which is half a stop smaller than expected. Does anyone know why this would be the case? With my DA300 and DA*50-135 the maximum apertures are f/5.6 and f/4.0 respectively as expected. Perhaps to ensure perfect accuracy of the focus. It may be a work in progress, though, and in future some firmware update may change it to f2.

05-29-2014, 06:41 PM	#4
DSims Veteran Member Join Date: Sep 2009 Location: Southern California Photos: Gallery \| Albums Posts: 3,236	Originally posted by Adam t seems that other AF lenses with F1.4 are also limited to F2.4 with the teleconverter (we tested the F and FA 50mm F1.4 in our in-depth review). This is obviously being forced through firmware, but the reasons for it are unknown. Perhaps to keep image quality to high standards... And this would make sense on the F or FA, but not necessarily on the DA*. Too bad if that's the reason.

05-29-2014, 07:23 PM	#5
Uluru Banned Join Date: May 2010 Location: Back to my Walkabout Creek Photos: Gallery \| Albums Posts: 2,535	Originally posted by DSims And this would make sense on the F or FA, but not necessarily on the DA. Too bad if that's the reason. In this case, DA55 is indeed a 35mm capable lens.

05-29-2014, 07:28 PM	#6
DSims Veteran Member Join Date: Sep 2009 Location: Southern California Photos: Gallery \| Albums Posts: 3,236	Originally posted by Uluru In this case, DA55 is indeed a 35mm capable lens. I'm not sure why you mentioned this; I was referring to the fact that the F and FA 50/1.4 need to be stopped down much more than the DA55 does if you want high IQ.

05-29-2014, 07:32 PM	#7
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,608	Originally posted by DSims I'm not sure why you mentioned this; I was referring to the fact that the F and FA 50/1.4 need to be stopped down much more than the DA55 does if you want high IQ. But the teleconverter amplifies imperfections in the lens, and wide-open they'd probably be quite easy to spot. Look at the bright side: many high-end teleconverters from other brands (like Nikon) won't even fit on a 55mm; they require tele lenses. Adam* PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

05-29-2014, 07:53 PM	#8
Sandy Hancock Moderator Site Supporter Join Date: Feb 2012 Location: Adelaide Hills, South Australia Photos: Gallery \| Albums Posts: 11,275 Original Poster	Rather dreamy at f/2.4 Brutally sharp at f/5.6

05-29-2014, 07:54 PM	#9
DSims Veteran Member Join Date: Sep 2009 Location: Southern California Photos: Gallery \| Albums Posts: 3,236	Originally posted by Adam But the teleconverter amplifies imperfections in the lens, and wide-open they'd probably be quite easy to spot. Look at the bright side: many high-end teleconverters from other brands (like Nikon) won't even fit on a 55mm; they require tele lenses. True, I guess even on the DA*55 it might be easy to recognize the imperfections if it were able to use wider apertures. ---------- Post added 05-29-14 at 07:57 PM ---------- Originally posted by Sandy Hancock Rather dreamy at f/2.4 Brutally sharp at f/5.6 Whadayaknow: It looks like proof arrived as I was typing!

05-30-2014, 03:44 AM	#10
VisualDarkness Veteran Member Join Date: Nov 2011 Location: Uppsala, Sweden Photos: Gallery Posts: 4,439	Still I think it's a bad choice to limit it like that, it doesn't hurt really to have the option even though the quality may suck bad. I guess they just played it safe.

05-30-2014, 07:08 AM	#11
pid Pentaxian Join Date: Jan 2010 Photos: Gallery Posts: 567	I think it has to do with the smaller diameter of the Lenssystem of the converter. There would be to much light reflection between lens and Converter. The "dreamy effect" will occur with all f-stops bellow f2.8. In Low Light situation you will get better results below f2.8 as in sunlight with hard contrasts. I tested it with all three FA Limiteds and the DA*55 with the same results. The "dreamy effect" disapears behind f2.8 in combination with the Converter this will be f4.0.

06-02-2014, 09:02 PM	#13
VisualDarkness Veteran Member Join Date: Nov 2011 Location: Uppsala, Sweden Photos: Gallery Posts: 4,439	Me neither. You can even get longer lenses used for the same price or less than the converter, still people even want it for the 18-135 or even 18-55. I just dislike limitations like that even though I understand the reasoning behind them.

06-02-2014, 09:32 PM	#14
Sandy Hancock Moderator Site Supporter Join Date: Feb 2012 Location: Adelaide Hills, South Australia Photos: Gallery \| Albums Posts: 11,275 Original Poster	I satisfactorily explained in my original post why I used the DA55 with the converter. Any other time I would of course use my FA77, or crop a shot with the DA55 mounted directly. I just thought it was interesting

06-19-2014, 04:25 AM	#15
zbrueningsen Veteran Member Join Date: Oct 2011 Location: Nebraska Photos: Albums Posts: 902	UluEU, have you used the DA 55 before? I really wanted an 85mm lens but didn't want to shell out what the FA 85 cost. So a 1.4 teleconverter was The idea. For me doing portraits is why. It isn't that we want a telephoto lens, but the DA 55 is simply a masterpiece of optics.