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04-15-2010, 02:13 AM   #1
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Witch good zoom at f2.8 + TC with it ?

Hi there,

I am looking for a replacement to my 70-300 Tamron. I need a fast lens. Since Pentax have some SDM issues, those lens are not an option for me (60-250, 50-135...).

Tamron, i am not very satisfied with my 70-300... i have also the 90mm macro, witch is sharp, but had a weird way of focussing...

So i am looking on Sigma. The 70-200mm f2.8 seem a good fit. The problem with this lens are :
- seem to have more than 3 versions of it: non sdm, sdm, and the new with the anti-vibration in it
- incompatibilty with teleconverter

My main concern is the TC. I want a 1.4x with it, but it seem that a Tamron or a Kenko 1.5x supposely works with it, but it doesn't seem to be worldwide.

Since i also want to use the TC on a future 300mm lens, it had to be compatible.

So, any good advice for me please?

04-15-2010, 05:03 AM   #2
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If you want the Sigma going with the current tc, you need the older pre-HSM versions. There are several users in this forum and the general consensus seems to be, that the pre-HSM pre-Macro version is the shrpest of all. I use it myself with the Sigma 1.4x tc quite regularily and cannot see a difference in the final image, between shots with and without that tc. The 2x tx has a very slight degrading infuence on the IQ, but very acceptable. Even that slight degradation might be contributed to my copy of the tc, as others have reported IQ just as good as with the 1.4x tc.

If you want the current HSM version of that lens, you need a third party tc, probably the Tamron 1.4x with the old Powerzoom contacts, which now serve as SDM contacts. I have not used that combination and cannot comment. I have the Kenko 1.5x tc with those contacts, but hardly ever use it, as the old Pentax tcs deliver much better IQ and for the Sigma lens I have the Sigma Apo tcs.

Honestly: If I would buy a 70-200/2.8 again, I would wait and search for the old pre-HSM version and use the matching Sigma Apo tcs. Thius combination is really a winning team. The compromise is, that you would need a separate tc for a 300mm prime later. But then, lens buying is almost always a compromise.

Ben
04-15-2010, 05:52 AM   #3
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I have a sigma APO 70-200F2.8 EX (Non DG Non macro) and both the 1.4x and 2x sigma APO - EX TCs.

This is referred to as version 1, for obvoius? reasons

I believe there are the following versions in order of production

APO 70-200F2.8 EX
APO 70-200F2.8 EX DG (same optical formula as version 1 but with coatings on rear element to prevent the already non existant reflection from the sensor)
APO 70-200F2.8 EX DG Macro
APO 70-200F2.8 EX DG Macro HSM

There may even be a DG Macro II version between the DG Macro and the HSM version. I don't really follow it that closely because I have been so pleased with the origonal that I see no reason to change.

The sigma TCs at present do not support the HSM version, and there is no clear release date for an HSM version of the TC.

IN addition, the TCs pass the lens data streight through the TC un modified, and therefore the aperture and focal length reported are for the prime lens, not the effective total aperture and focal length.

This may or may not be a problem for anyone using the TC because it has the following impacts.

for shake reduction the focal length used by the SR is for 1/2 the actual focal length, and depending on camera body, and viewing screen there are metering errors that are introduced because the camera does not know the actual aperture.

The metering issue is the most noticable with the K10D and K20D. It will result in a constant over exposure by 1-2 stops. It is most serious in terms of impact with the K10D because while it can be corrected in auto exposure modes, using exposure compensation, for some reason pentax removed exposure compensation in manual mode. As a result, you have to mentally under expose all the time. All other bodies, as far as I know (for sure my K7D and *istD) allow compensation in manual.
04-21-2010, 08:43 AM   #4
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QuoteOriginally posted by Ben_Edict Quote
If you want the Sigma going with the current tc, you need the older pre-HSM versions. There are several users in this forum and the general consensus seems to be, that the pre-HSM pre-Macro version is the shrpest of all. I use it myself with the Sigma 1.4x tc quite regularily and cannot see a difference in the final image, between shots with and without that tc. The 2x tx has a very slight degrading infuence on the IQ, but very acceptable. Even that slight degradation might be contributed to my copy of the tc, as others have reported IQ just as good as with the 1.4x tc.

If you want the current HSM version of that lens, you need a third party tc, probably the Tamron 1.4x with the old Powerzoom contacts, which now serve as SDM contacts. I have not used that combination and cannot comment. I have the Kenko 1.5x tc with those contacts, but hardly ever use it, as the old Pentax tcs deliver much better IQ and for the Sigma lens I have the Sigma Apo tcs.

Honestly: If I would buy a 70-200/2.8 again, I would wait and search for the old pre-HSM version and use the matching Sigma Apo tcs. Thius combination is really a winning team. The compromise is, that you would need a separate tc for a 300mm prime later. But then, lens buying is almost always a compromise.

Ben
Hi Ben,

So, pre-hsm will be better, but i have the feeling that the noise of the zoom-in/out will bother me. Is it that bad ?

The Kenko 1.5x is difficult to find, the only one i saw available on BHphoto: 1.5x DG AF Teleplus Teleconverter for Pentax AF witch isn't the good one for HSM.

I don't mind buying a non macro, i already have a 1:1 macro lens. I might not mind buying the non-HSM, as long as it focus that fast as the HSM, and that the noise isn't so bad

If i need another tc for a 300mm lens, so be it... as long as i can use one of them with my macro lens

Can you tell me witch exact model you have for the sigma 1.4x tc ? I just want a win-win duo

thanks,

04-21-2010, 08:50 AM   #5
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QuoteOriginally posted by Lowell Goudge Quote
I have a sigma APO 70-200F2.8 EX (Non DG Non macro) and both the 1.4x and 2x sigma APO - EX TCs.

This is referred to as version 1, for obvoius? reasons

I believe there are the following versions in order of production

APO 70-200F2.8 EX
APO 70-200F2.8 EX DG (same optical formula as version 1 but with coatings on rear element to prevent the already non existant reflection from the sensor)
APO 70-200F2.8 EX DG Macro
APO 70-200F2.8 EX DG Macro HSM

There may even be a DG Macro II version between the DG Macro and the HSM version. I don't really follow it that closely because I have been so pleased with the origonal that I see no reason to change.

The sigma TCs at present do not support the HSM version, and there is no clear release date for an HSM version of the TC.

IN addition, the TCs pass the lens data streight through the TC un modified, and therefore the aperture and focal length reported are for the prime lens, not the effective total aperture and focal length.

This may or may not be a problem for anyone using the TC because it has the following impacts.

for shake reduction the focal length used by the SR is for 1/2 the actual focal length, and depending on camera body, and viewing screen there are metering errors that are introduced because the camera does not know the actual aperture.

The metering issue is the most noticable with the K10D and K20D. It will result in a constant over exposure by 1-2 stops. It is most serious in terms of impact with the K10D because while it can be corrected in auto exposure modes, using exposure compensation, for some reason pentax removed exposure compensation in manual mode. As a result, you have to mentally under expose all the time. All other bodies, as far as I know (for sure my K7D and *istD) allow compensation in manual.
So, it seem that you and Ben have the same lens, and tc. Thanks a lot for the 4 70-200mm version, one more than i tought !

I am not sure i understand what you said about the metering issue. Since i have a K20D, in a practical use, is it that bad ? Having to under expose one you know that is okay i think...


By the way, it is the only solution i can have for a fast zoom lens ? Maybe there is another solution that i didn't see?

The APO 70-200F2.8 EX or EX DG isn't available on ebay
04-21-2010, 11:45 AM   #6
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QuoteOriginally posted by TanGU Quote
Hi Ben,

So, pre-hsm will be better, but i have the feeling that the noise of the zoom-in/out will bother me. Is it that bad ?

The Kenko 1.5x is difficult to find, the only one i saw available on BHphoto: 1.5x DG AF Teleplus Teleconverter for Pentax AF witch isn't the good one for HSM.

I don't mind buying a non macro, i already have a 1:1 macro lens. I might not mind buying the non-HSM, as long as it focus that fast as the HSM, and that the noise isn't so bad

If i need another tc for a 300mm lens, so be it... as long as i can use one of them with my macro lens

Can you tell me witch exact model you have for the sigma 1.4x tc ? I just want a win-win duo

thanks,

The Sigma tcs for Pentax AF mount are so far available only in one version, that with the screwdriver AF. There might have been a pre-DG and a DG version, but I don't know that - and honestly I do not care abou that DG designation, as I cannot see any difference in flareing/ghosting between my older pre-DG and my later DG Sigmas.

The screwdriver AF is ofcourse somewhat noisy. But the K10/K20 is not really a silent camera, so for me personally, the AF action does not add more distraction, than the camera provides already... And AF speed is en par between SDM and screwdriver AF, which at least comparissons between lenses which are available in both versions indicate.

Lowell and myself have the same version of the Sigma and we both have a similar regard for that lens and the 1.4c tc. But Lowell's 2x tc is better than mine

I personally think, this lens is the best solution for a fast telezoom in Pentax AF mount, so some would argue the Pentax FA 80-200/2.8 being better. May be - but at a steep price for a lens that has been out of production for 10 years or so.

The next option would then be one of the SDM/HSM zooms, either by Sigma or by Tamron, combined with the Tamron tc - if you can find one for a not too absurd price.

Another option, if the 300mm reach is important, would ofcourse be the Sigma 100-300/4. This seems to be so good, that the difference to a 300mm prime lens gets unnnoticed in real shots. This option may save you the need to buy a tc.

Ben
04-21-2010, 11:53 AM   #7
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QuoteOriginally posted by TanGU Quote
So, it seem that you and Ben have the same lens, and tc. Thanks a lot for the 4 70-200mm version, one more than i tought !

I am not sure i understand what you said about the metering issue. Since i have a K20D, in a practical use, is it that bad ? Having to under expose one you know that is okay i think...


By the way, it is the only solution i can have for a fast zoom lens ? Maybe there is another solution that i didn't see?

The APO 70-200F2.8 EX or EX DG isn't available on ebay
for the metering issue, on a K20 it will be easier to cope with than K10D.

the impact is that the metering at all apertures will be wrong by between 1 and 1.5 stops depending on whether you use the 1.4x or 2x TC. This is easy to establish, and once you have it exactly, you set exposure compensation for the lens and you are done with it.

On the K10D there is a second issue. EV comp is disabled in manual mode, so when you meter, each time youdo, you need to do a test shot or adjust the exposure manually by increasing the shutter speed, or stopping down a little. it is a real pain.

Do a search in the market place and on EBAY. Usually there are one or two for sale.
04-21-2010, 11:58 AM   #8
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QuoteOriginally posted by Ben_Edict Quote
The Sigma tcs for Pentax AF mount are so far available only in one version, that with the screwdriver AF. There might have been a pre-DG and a DG version, but I don't know that - and honestly I do not care abou that DG designation, as I cannot see any difference in flareing/ghosting between my older pre-DG and my later DG Sigmas.
my 1.4x is a non DG version, my 2 x is a DG version. When I bought thelens origonally, I didn;t like the 2x I saw, but then several years later, when I wanted more length, I got the 2x DG at adorama, and I have been very pleased with the performance. I don't know if there is something else they have done optically between DG and non DG.
QuoteQuote:
The screwdriver AF is ofcourse somewhat noisy. But the K10/K20 is not really a silent camera, so for me personally, the AF action does not add more distraction, than the camera provides already... And AF speed is en par between SDM and screwdriver AF, which at least comparissons between lenses which are available in both versions indicate.

Lowell and myself have the same version of the Sigma and we both have a similar regard for that lens and the 1.4c tc. But Lowell's 2x tc is better than mine
my TC say's thanks
QuoteQuote:

I personally think, this lens is the best solution for a fast telezoom in Pentax AF mount, so some would argue the Pentax FA 80-200/2.8 being better. May be - but at a steep price for a lens that has been out of production for 10 years or so.

The next option would then be one of the SDM/HSM zooms, either by Sigma or by Tamron, combined with the Tamron tc - if you can find one for a not too absurd price.

Another option, if the 300mm reach is important, would ofcourse be the Sigma 100-300/4. This seems to be so good, that the difference to a 300mm prime lens gets unnnoticed in real shots. This option may save you the need to buy a tc.

Ben
I have heard, cant say first hand that some people think the 100-300 is a little soft at 300. Also, for me, I use the lens with and without TCs, and F2.8 is very important for me, and perhaps the OP as well. SOmething to consider although I do use the lens an awful lot with a TC, for indoor stage performances I shoot it without the TC and use it almost exclusively wide open

04-21-2010, 09:32 PM   #9
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QuoteOriginally posted by TanGU Quote
The APO 70-200F2.8 EX or EX DG isn't available on ebay
I have one on the marketplace w/ a 2x tc
https://www.pentaxforums.com/forums/photographic-equipment-sale/98736-sale-si...worldwide.html
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