Luminous Landscape Forum

Equipment & Techniques => Medium Format / Film / Digital Backs – and Large Sensor Photography => Topic started by: Drew Harty on May 09, 2007, 06:46:11 am

Title: Sharpness of Extension Tubes
Post by: Drew Harty on May 09, 2007, 06:46:11 am

Hello,

Has anyone tested the sharpness difference between usning extension tubes versus a dedicated macro lens?  Specifically I was thinking of purchasing a 12mm and/or a 24mm extension tube to use with with a Mamiya 80mm AF lens.  Are Extension tubes capable of producing the same degree of sharpness and tonal contrast as a macro lens?

Thanks,

Drew Harty

Title: Sharpness of Extension Tubes
Post by: zzzone on May 09, 2007, 07:23:29 am

Quote

Hello,

Has anyone tested the sharpness difference between usning extension tubes versus a dedicated macro lens?  Specifically I was thinking of purchasing a 12mm and/or a 24mm extension tube to use with with a Mamiya 80mm AF lens.  Are Extension tubes capable of producing the same degree of sharpness and tonal contrast as a macro lens?

Thanks,

Drew Harty
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Title: Sharpness of Extension Tubes
Post by: zzzone on May 09, 2007, 07:32:45 am

Quote

Hello,

Has anyone tested the sharpness difference between usning extension tubes versus a dedicated macro lens?  Specifically I was thinking of purchasing a 12mm and/or a 24mm extension tube to use with with a Mamiya 80mm AF lens.  Are Extension tubes capable of producing the same degree of sharpness and tonal contrast as a macro lens?

Thanks,

Drew Harty
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Hi

I have both the 80mm with an extension tube and recently bought the 120mm manual on ebay for just over 200GBP.  I haven't done a direct comparison but I would say don't miss out on the 120mm for the money, it is very sharp.

Steve

Title: Sharpness of Extension Tubes
Post by: PdF on May 09, 2007, 09:45:18 am

Quote

Hi

I have both the 80mm with an extension tube and recently bought the 120mm manual on ebay for just over 200GBP.  I haven't done a direct comparison but I would say don't miss out on the 120mm for the money, it is very sharp.

Steve
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Sharper than the 80mm Macro ?

PdF

Title: Sharpness of Extension Tubes
Post by: MarkKay on May 09, 2007, 10:21:23 am

i have been using my extension tubes on the Hassy H2 with the 50-110 zoom and Rollei XAct-2 with the non macro 120mm and 180mm schneider digitar lens.  For the former, I have the dedicated 120mm HC macro lens as well.  I have never compared the macro and zoom+ extension tubes directly but i am very impressed with my results using the combo.  I have a  leaf aptus 65 digital back so I am not sure how accurate any comparisons might be because it is my understanding that there  tends to be some edge distortion and sharpness falloff at the edges of non-dedicated macro lens when used with  an extension  tube. With a cropped sensor, I am not sure how accurate edge testing might be. Of course it is sometimes harder to get the exact framing with the extension tube combo but in general, I am very impressed with my combo.  At some point, I should do some direct comparisons.

Quote

Hello,

Has anyone tested the sharpness difference between usning extension tubes versus a dedicated macro lens?  Specifically I was thinking of purchasing a 12mm and/or a 24mm extension tube to use with with a Mamiya 80mm AF lens.  Are Extension tubes capable of producing the same degree of sharpness and tonal contrast as a macro lens?

Thanks,

Drew Harty
[a href=\"index.php?act=findpost&pid=116529\"][{POST_SNAPBACK}][/a]

Title: Sharpness of Extension Tubes
Post by: Drew Harty on May 09, 2007, 10:47:04 am

Quote

i have been using my extension tubes on the Hassy H2 with the 50-110 zoom and Rollei XAct-2 with the non macro 120mm and 180mm schneider digitar lens.  For the former, I have the dedicated 120mm HC macro lens as well.  I have never compared the macro and zoom+ extension tubes directly but i am very impressed with my results using the combo.  I have a  leaf aptus 65 digital back so I am not sure how accurate any comparisons might be because it is my understanding that there  tends to be some edge distortion and sharpness falloff at the edges of non-dedicated macro lens when used with  an extension  tube. With a cropped sensor, I am not sure how accurate edge testing might be. Of course it is sometimes harder to get the exact framing with the extension tube combo but in general, I am very impressed with my combo.  At some point, I should do some direct comparisons.
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I also shoot with the Leaf Aptus 65.  I have been shooting lens test of a target with the Aptus 65 and have been surpised at the differences in resolution at different f/stops on my Mamiya 80mm and 45mm lens.  The test have made me concerned about using extension tubes with the 80mm, but if there is only a difference in edge sharpness the combo would be acceptable for my purposes, particularly with the Aptus 65.

Thanks,

Drew Harty