[hinman]

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I quoted this from the long threaded discussions in Tamron 1.4x converter pictures as after few test with the TC, I find the $69.99 new TC from Wolfe's camera store quite good and it does well when I try it on my Tamron 70-300 Di LD Macro.

If you are in the market looking for the Tamron 1.4x TC without much success, I recommend to give this TC a try. The store seems to post the TC in the online store and sometime in ebay store

Wolfe's Camaera online store

• Promaster AF 1.7X Teleconverter 2009 : Wolfe's Camera Shop
• In ebay: eBay My World - wolfes.com

John, thanks for the summary and I can attest to your findings for both Tamron 1.4x and Promaster 1.7x TC. I am on the cheapo side in pushing a consumer tele zoom to its limits. Do you notice more PF/CA when you use your 1.4x? I have much more showing of PF/CA on my Tamron when the 1.4x TC is used. And PF is a bit better controlled when Promaster is used. Perhaps it is more related to Tamron zoom's PF, more pronounced with the TC.

Without a tripod, I find the 1.4x TC work very well even at 420mm. But a bit more difficult for 510mm with the Promaster. Registration of 300mm for SR is very taxing for long distance objects in hand holding.

Promaster 1.7x AF TC | Tamron 1.4x Pz-AF MC4



Some hand-held casual walk around test shots

Promaster 1.7x AF TC

#1
1/400 sec, f/7.1, 510mm, iso 200, about 15 feet away


#2
1/400 sec, f/7.1, 226mm, iso 200, about 12 feet away


#3
1/160 sec, f/7.1, 153mm, iso 200, about 8 feet away


#4
1/320 sec, f/9.0, 242mm, iso 400, about 6 feet away


#5
112mm


#6
510mm


#7
127.5mm


#8
510mm


#9
510mm


All with Promaster 1.7x AF TC

Full set flickr test shots
PF/CA is better controlled in Promaster 1.7x TC

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Last edited by hinman; 08-12-2008 at 03:19 PM.

[hinman]

While the promaster 1.7x should have about 1.5 f/stop loss, the promaster TC has a MC coating and though I still find traces of PF/CA in the test shots. PF/CA is better controlled when I use the Promaster TC.

When I use the Tamron 1.4x TC on the Tamron 70-300 Di LD Macro zoom, the PF/CA is more pronounced and it become annoying though the IQ are pretty reasonable in both TC considering the light loss and the conventional wisdom that TC should only be used with prime with fast speed.

I use the Promaster 1.7x TC to shoot hummingbird at 510mm without use of tripod

Promaster 1.7x AF TC


Tamron 70-300 Di LD Macro

#1
at 510mm
(in similar scene when Tamron 1.4x TC is used, all branches with
highlight are purple)


#2


#3


#4


#5


#6


Promaster 1.7x AF TC

I am amateur and the Promaster 1.7x, costing $69.99 brand new, has enabled my consumer grade Tamron 70-300 Di LD zoom to reach 510mm with no issues in AF though the f/stop loss, and all the other known caveats in using TC. The best part about that TC, when used in Tamron zoom in particualr, is the better control of PF/CA. PF/CA is NOT all gone but I found much better controlled in comparing to Tamron 1.4x TC.

[hinman]

About the PF/CA, here is the horrible shot from me on using the Tamron 1.4x

#1
Using Tamron 1.4x on Tamron 70-300 in 420mm
1/640 sec, f/7.1, 420mm, iso 400, 0 Ev


Tamron 1.4x Pz-AF MC4


#2
And on similar shot
with Promaster 1.7x on Tamron 70-300 in 510mm
on a different day with different lighting but in similar timing in the morning
1/500 sec, f/7.1, 510mm, iso 400, 0 Ev


Promaster 1.7x AF TC

It is not scientific but base on my few days of testing, I find PF/CA a bit better with the Promaster when using on the Tamron zoom, not as pronounced as with the Tamron 1.4x.

Thanks,
Hin

[k100d]

thanks for bringing this up. looks like a good alternative to the usual Pentax or Tamron TC's that are expensive. how did you find the overall quality of the photos after TC? cuz the ones you've posted up look really good so far

[hinman]

thanks for bringing this up. looks like a good alternative to the usual Pentax or Tamron TC's that are expensive. how did you find the overall quality of the photos after TC? cuz the ones you've posted up look really good so far

I find the overall quality quite usable to me. When used on my Tamron 70-300 zoom, I find the combination yielding to 510mm quite alright for hand holding and picture quality comes out reasonable. But then, I am not picky and without trained eyes to see the degradation on image quality. And I can simply assume that the TC will work better with prime lens. If one can find the Tamron 1.4x TC, I would think the Tamron has an edge in terms of picture quality and less light loss. But the promaster at $69.99 is a good alternative if the tamron 1.4x turns out to be impossible to find and with huge price tag.

The other good alternative with similar price to the promaster is the Kenko 1.5x TC with auto focus. I heard from others that the promaster won't work with AF with SDM lens though I see the two yellow SDM contacts in the inner housing of the TC. And I don't have the DA * lens to confirm. So if you have the DA * lens, you should confirm the findings and bear that in mind before the purchase.

I have good discussion with another Pentaxian in Dpreview and he managed to use the 1.7x TC with his Tamron SP 90mm f/2.8 to add distance to his 90mm with 153mm after the multiplier and he manage to get good decent macro on butterfly and the TC serves to add extra distance away from the butterfly for him

• Promaster 1.7x AF TC on Tamron 90mm macro: Pentax SLR Talk Forum: Digital Photography Review
• Tripod 100% crops using Tamron 90mm macro with and without Promaster TC: Pentax SLR Talk Forum: Digital Photography Review

[OrenMc]

Thanks hinman,

I was asking about this TC a couple months ago. Glad to see some results.

[hinman]

Thanks hinman,

I was asking about this TC a couple months ago. Glad to see some results.

You should see how another Pentaxian uses the TC to add distance to his Tamron 90mm. And he later compares the shot with and without the TC and he is quite satisfied with the results in using the TC on a macro AF lens

• Tripod 100% crops using Tamron 90mm macro with and without Promaster TC: Pentax SLR Talk Forum: Digital Photography Review

[heatherslightbox]

I just ordered the Promaster 1.7x TC (from Wolfe Camera) for myself to try on the DA55-300, as well as my Tammy 28-75, A50/1.7, and A100/4 macro. I'm one of those who really doesn't need an extra long lens very often, so it's not worth it to shell out a bunch of money for something I might use a few times in a year, so this makes more sense.

Hin, your pics with the Tammy 70-300 + TC look great! I'm really looking forward to seeing what this TC will do with the 55-300. I really like the idea of having a 765mm (after 1.5x crop and 1.7x of TC) lens for less than $100..

Even with as slow as our "consumer" telezooms are on the long end, as long as we're not planning on shooting in the dark, stopping down to f/11 isn't that big of a deal.

I'll be posting once I get the TC and try it out.

Heather

[hinman]

I am glad that you take the plunge with the promaster 1.7x which I find a great bargain for $69.99 from Wolfe's camera as a brand new item. Several people who discussed with me in dpreview are quite satisfied with the purchase.

All the best,
Hin