use of kenko mc7 macro tele 2x on pentax k-30

Started Feb 9, 2013 | Questions thread
Ursinho73 Regular Member • Posts: 430
Re: use of kenko mc7 macro tele 2x on pentax k-30

audiobomber wrote:

Ursinho73 wrote:

Mike, your specific questions were already answered very well and extensively. Thus, let me just add that the important part of the product's name is "macro" - not "tele". The converter will turn your nifty-fifty into a manual but otherwise fully fledged 3.5/100 macro lens capable of shooting 1:1 macros. As such, particularly with the lens stopped down to its sweet spot of f4.0-8.0, the combo works very well. It is probably the best "macro on the cheap" solution around. Happy shooting.

Hi Hannes. Magnification depends on the lens. The SMC 50mm has a native magnification of .15X. Adding a 2X TC doubles the magnification to 0.3X, which is 1:3 macro, not 1:1.

Dan, as Ron and Kent already pointed out you seem to confuse the product in question with a standard 2x TC - but it's not. It is basically an adjustable extension tube specifically made to provide 1:1 macro for 50mm lenses - with an added 2x TC for increased working distance.

audiobomber wrote:

Typical settings for my 100mm macro would be 1/180s, f11-16, and try to keep ISO below 800 for the K20D, ISO 1600 for the K-01.

That are adequate settings for a dedicated macro lens or a normal lens with a Raynox in front of it. However, when the thread opener uses his macro-tele-converter he should limit himself to f-stops of 4.0-8.0 max. because of the 2x TC effect which doubles the effective f-stop at any given apperture. Your recommendation would lead (on Mike's equipment !) to effective f-stops of 22 - 32 which is way to deep in diffraction territory.

audiobomber wrote:

"Best" depends on one's priorities. A Raynox diopter is best in some ways, extension tubes are best in some ways, reversing a lens is best in some ways.

Well, this is some kind of a common place statement, isn't it? Anyway, for the situation of Mike, who is about to combine his 1.8/50 with his new macro-tele-converter and to whom I addressed my "best solution" remark, I stand by my claim.

Reversing a DA 50mm lens is no option, as the lens has no aperture ring.

Extension tubes are actually just a less flexible version of what Mike bought. The added TC on his product has the highly welcomed effect of doubling the working distance. True, in theory the TC will lead to an image degradation as well, but with the very high center resolution of a good 50mm lens at medium apertures he would need to print VERY VERY big to practically see any of that degradation in his final image.

Finally, a Raynox on a standard prime will give a (practically) fixed magnification at a fixed working distance (and a pretty short one at that) with a slightly lesser image quality - at least it did in my comparison shots against the macro-tele-converter (owning and using both).



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