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03-07-2014, 10:12 AM - 2 Likes   #241
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Cross posted from the other TC thread...

Heres a few more images for you to look at..
A few quick images from this morning...

A crow stopped by up on the hill. The impressive thing to me in this shot is the crow is at least 40 meters away from me, the image is cropped to maybe 50% of it's original size and it still shows good feather detail. I'm not sure you could make the argument this shot could have been as good without the TC.



And of course, your usual squirrel images.







Full reach image 60-250 with 1.7 (shows as 450 in exif)



Full reach image 60-250 with 1.4 (show as 350mm in exif)


Full reach image 60-250 (shows as 250 in exif)


60-250 with 1.7 scaled as close as I could guestimate to 250..


60-250 with 1.4 exif says 252 mm.


The new TC 1.4 is definitely easier to use, calculates your focal length with the TC on and will probably live on my 60-250 when needed. The 1.7 TC is more difficult to use. But after the initial focus, the short throw of the TC acts as a limiter making AF very quick, it has noticeably more reach, but it doesn't accurately report the change in zoom setting, reporting everything as the max. available setting, so my 250 mm image (above) in the exif show 450.

The 1.7 also ads partial AF to MF lenses which the 1.4 does not.

I'm planning on keeping both.

03-07-2014, 10:34 AM   #242
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@Norm thanks for the pics..from what I see maybe a bit more contrast with the 1.4,if both are PP the same way,but IQ is about the same.I wonder if the DA*300 will be much different?? More contrast gives the illusion of a sharper image though would need raw files to really compare
03-07-2014, 10:37 AM   #243
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QuoteOriginally posted by Shanti Quote
@Norm thanks for the pics..from what I see maybe a bit more contrast with the 1.4,if both are PP the same way,but IQ is about the same.I wonder if the DA*300 will be much different?? More contrast gives the illusion of a sharper image though would need raw files to really compare
I used exactly the same post processing preset on all images 5 images, so no difference in processing. I'd expect similar results on any other lens.

Oops correction, any other high quality lens. I'd point out, I'm not testing these converters on my consumer level lenses, because when I tested them with the 1.7, the CA and purple fringing were magnified to the point of being unbearable.

Last edited by normhead; 03-07-2014 at 10:45 AM.
03-07-2014, 11:30 AM   #244
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@normhead, were those shots taken with equivalent f-stops? The OOF blur seems substantially different between the last three shots which should have all been at around 250mm with the bare lens looking like it has been stopped down more than the other two shots.

03-07-2014, 12:29 PM - 1 Like   #245
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QuoteOriginally posted by mikemike Quote
@normhead, were those shots taken with equivalent f-stops? The OOF blur seems substantially different between the last three shots which should have all been at around 250mm with the bare lens looking like it has been stopped down more than the other two shots.
I checked the values in the EXIF, (you can do that too by downloading the pictures) and t F-stops do vary. I may have to reshoot...

A couple more quick and dirty observations.

I've been carrying both the A-400 and the DA* 60-250. I'd like to leave the A-400 home, so I wanted to test which was better the 1.4 and 60-250 or the A-400. The first trial would indicate the 60-250 with the TC is better. Two fairly representative images.

The scene..


A-400


DA* 60-250 with 1.4 TC


Initial results would suggest that the 60-250 with 1.4 TC gives a better image than my A-400. Part of that may be that the auto focus is better than my manual focus. Regardlerss if the reason, looking at 10 images, my guess is I'm better off with the DA*60-250. Whether it would be different with a bench test, I don't care, I don't take a bench with me in the field. That would suggest that in the field, I can leave the A-400 home, or sell it, and bring the 1.4 TC instead. That will take more than a pound out of my pack.

If I sell it, that will go a long way towards the cost of the TC.

Last edited by normhead; 03-07-2014 at 12:34 PM.
03-07-2014, 12:49 PM   #246
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would like to see cīsame test with the1.7 TC,if not too much a hassle,on the 60-250
03-07-2014, 02:17 PM - 1 Like   #247
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OK, since I was interested, I went out again... this time, 3 shots at each setting picked the best of each,

The scene shot at 250mm.


The test chart, cropped to the size of the chart @250mm.


The test chart, cropped to the size of the chart @350mm. DA*60-250 + 1.4


The test chart, cropped to the size of the chart @400 mm (A-400)


The test chart, cropped to the size of the chart @450mm. DA* 60-250 + F 1.7 TC


The test chart, cropped to the size of the chart @560 mm (A-400 +1.4 TC)


The trend seems to be a constant improvement with longer focal length. No apparent degradation of the image due to TC use. IN this series the A-400 came out better than the DA*60-250 with the 1.4. I might have to devise a tie break.
03-07-2014, 08:45 PM   #248
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On this test the 1.7 seems a bit sharper than the 1.4, its really splitting hairs between these 2..I expected a bigger difference with the HD coating etc..

03-08-2014, 06:53 AM - 2 Likes   #249
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QuoteOriginally posted by Shanti Quote
On this test the 1.7 seems a bit sharper than the 1.4, its really splitting hairs between these 2..I expected a bigger difference with the HD coating etc..
That's what I'd expect... in my experience when you select a target like this, the more resolution you have on the image, the sharper it appears to be. One of the engineers estimated an uncoated lens would have 5% flare etc. an SMC might be 1% flare and reflection, the new HD coating might be .75%. In the overall scheme of things it's no a big difference, but as you get up into better lenses and equipment, the differences that you can buy become smaller and smaller. A D800 sensor is twice the size of an APS-c sensor and it can achieve 4000 lw/ph. But a K-3 can achieve 2700 lw/ph. 100% larger sensor, about 50% more resolution.. 3 times the cost. At the high end, the cost of relatively small improvements can be very big. In this cans the TC is HD, but the lens isn't, so it's possible any noticeable improvement will be even less.

A few more images, this time using the Sigma 70 macro and 1.4 TC.. which registers as a 98mm ƒ4.

K-3 SIgma 70 macro with HD DA 1.4 TC

Wide open at ƒ4


Stopped down to ƒ22


Up close and personal @ ƒ22

Last edited by normhead; 03-08-2014 at 07:07 AM.
03-08-2014, 08:08 PM   #250
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@Norm I know what you mean,as I sell/repair musical instruments & between say a flute for $3000 & one for $10000 the difference in tonal quality is about 5-10 %...
03-08-2014, 09:57 PM   #251
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QuoteOriginally posted by Shanti Quote
@Norm I know what you mean,as I sell/repair musical instruments & between say a flute for $3000 & one for $10000 the difference in tonal quality is about 5-10 %...
Yes - but the best 1000 or so concert flautists in the world, performing in the acoustically best hundred or so concert halls can make that 5% meaningful.
03-08-2014, 11:29 PM   #252
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I hope someone can try the new tc on one of the older camera bodies to see if it will work. Not sure why it would not work on my K-200D.

Rick
03-09-2014, 02:40 AM   #253
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QuoteOriginally posted by Rick in Ohio Quote
I hope someone can try the new tc on one of the older camera bodies to see if it will work. Not sure why it would not work on my K-200D.

Rick
It should work but SDM AF with the TC will most likely be bad if even useful.
Otherwise, everything should be fine IMO.
03-09-2014, 03:36 AM   #254
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Compatability with other lenses

Can anyone tell me if this new teleconverter is compatible with sigma and tamron lenses? everyone seems to be talking about pentax lenses and complaining! they are not the only lenses used on pentax camera's!
03-09-2014, 03:41 AM - 1 Like   #255
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A better question is, are 3rd-party Sigma and Tamron lenses compatible with this OEM teleconverter?
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