[Pentaxor]

I just recently purchased a bargain Vivitar S1 90/2.5 + 1:1 macro adapter in C/FD mount. although I would had preferred getting one in K-mount (whether it is the Tokina or Vivitar), but it's scarcity and present market price is a bit of a challenge especially in K-mount. I could simply bought one but I'm reserving the big bucks on a different lens. so I just bought an FD/K adapter for this cheap lens instead.

so how did this combo worked out so far? here are some initial test results and evaluation afterwards.

the test is conducted into 4 several ways:

1.> lens+macro adapter + FD/K adapter with correction elements
2.> lens+macro adapter + FD/K adapter w/o correction elements
3.> lens+FD/K adapter with correction elements
4.> lens+FD/K adapter w/o correction elements


I wont bother to show the results with the macro adapter as it's generally the same results with the one without it. the only difference is that I lose infinity and increase my macro focus distance.

what is interesting to note is that I don't find the need for the macro adapter unless you really want to increase you magnification further beyond 1:1, since the FD/K lens with the correction elements already produces a 1.43x magnification factor, which works well if you are shooting macros without the heavy burden of adding weight caused by the macro adapter.

now to the more interesting stuff, I used the FD/K with and without it's correction elements. the elements on the adapter are easy to remove. although such removal would result to losing infinity focus but would also result to retaining atleast close to a 90mm focal length image wideness and preserve the IQ at it's optimal state and doesn't lose a considerable amount of light. this works well as long as you dont shoot to infinity.

here is the result for doing so: w/o correction elements. shot close to MFD at f2.5 wide open



now the next 2 images are shot with the correction elements present. there is a considerable loss of light here so exposure was adjusted about 1 stop or over inorder to replicate the same level of exposure as the one without the correction elements. the correction elements also produced a considerable amount of magnification which would make a 90mm lens turn into a 125mm lens. this might work well for people looking for a longer telephoto reach. it is also very effective at doing macros and close-ups. there is a very slight IQ degradation due to magnification when pixel-peep but not field relevant nor noticeable enough to be even given any real attention. I believe this is normal especially with the correction and magnification caused by the lens. magnification would also magnify any weakness the lens may possess. such magnification and correction lenses also produces oof circles which I consider as normal. the lens may also display a glow around bright objects and bleeding but was not evident on the photos presented. this maybe because I used a deep hood here or the color bleeding and glow is only obvious or apparent on medium distance to infinity shots( longer distance). however, this glow and bleeding somehow is eliminated by avoiding shooting at wide open or stopping further down. although the photos I've shown which were shot at f2.5 wide open doesn't appear to display such bleeding.

here are 2 shots close to MFD done wide open at f2.5 with the correction elements installed: notice the increased magnification




as a summary, the FD/K adapter works. but can also work as a double edge blade as well. it can only be as good as the lens you use for it. the added correction elements will enable you to shoot at infinity and give you a focal length equivalent of 125mm which is great for those who want to shoot at longer focal lengths. it is also great for macro because you can shoot closer plus the added benefit of an additional magnification. the sharpness, detail and contrast of the lens doesn't appear to suffer that much as perceived by others, well atleast for the lens that I used as an example. it is still superbly performing, although I feel that using the lens without the correction elements gives me that top notch/optimum IQ without any tiny little and minute hiccups that can be noticed from extreme pixel peeping. the BOKEH is superb and unbelievably smooth with or w/o the correction elements, which is the most important aspect of this lens.

my only 2 gripes about this combo is my inability to use the "A" exposure setting of the lens for metering and I would had preferred using this lens as a pure 90mm short telephoto, especially for it's bokeh at a wider perspective rather than at an extended 125mm equivalent.

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Last edited by Pentaxor; 05-12-2010 at 11:34 PM.

[Just12hvFun]

Thanks for the great review, Pentaxor

I almost bought one of this last week but didn't know enough to commit

This effort of yours works wonders for people like us who's considering to get one

I notice you also have the Sigma 70mm and the Pentax 100mm with you

You must have done some comparison among them

Anything opinion that you can share with us please

[Pentaxor]

Thanks for the great review, Pentaxor

I almost bought one of this last week but didn't know enough to commit

This effort of yours works wonders for people like us who's considering to get one

I notice you also have the Sigma 70mm and the Pentax 100mm with you

You must have done some comparison among them

Anything opinion that you can share with us please

your welcome. as comparison to my other macros, I am considering a side by side comparison between the 3 lenses. however, eventhough I havent done that yet, I do see the differences between the 3 lenses. the FA100s asset is the color, the Sigma 70 is the sharpness and contrast, and the Vivitar or Tokina 90mm f2.5 for its bokeh.

I however feel that the sharpness between the Sigma 70 and Tokina are somehow neck and neck. there are situations I feel the Sigma is slightly sharper and there are situations that the Vivitar is. but when it comes to bokeh, the Vivitar is a trump card.

[Just12hvFun]

Thanks for the sharing, Pentaxor

It really does live up to its name of 'BOKINA'

[GhoSStrider]

Thanks for the review. How far can you focus without the corrective elements?

[Lowell Goudge]

The canon adaptor acts as about a 15mm extension tube. The adaptor itself is 12pm thick and there I'd the shorter canon registry distance to consider also

These findings mirror mine with the adaptor. The conclusion being it would be worthwhile if you happen upon a portrait or medium tele at a really good price

[GhoSStrider]

Cool! Thanks for the info!