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12-05-2007, 03:24 AM   #1
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31mm Reversed

As promised this AM here are a couple of shots using a 31mm reversed on a K10D. As advised here
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care must be taken with the three stepup/down rings needed to fit the 58mm filter thread to the 52mm reversing ring thread and provide enough extension for the built in lens hood to clear the camera face.

Magnification is about 2:1

Hope this works.

David

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12-05-2007, 03:49 AM   #2
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I'm going to swim against the recent tide of positive comments on how good these reversed shots look.

I frankly don't like the images that a reversed lens creates most of the time. These shots are noisy, I see nothing in the images that is sharp. The colours look off and I find the bokeh harsh.

Sorry to be so harsh but I've given this a go awhile back and never liked the results. Once I got a good, dedicated macro lens I could see that the quality was 10x what a reversed lens could do.

Plus to top it off the reversed lens is a pain to focus and not much good for anything that moves. IMO you'll spend money on rings and extenders that would be far better spent on a dedicated lens.
12-05-2007, 04:01 AM   #3
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Thanks for trying it David. It saves me the money of buying the extra rings.

For me I think it is much too close, and as Peter mentions it looks as though it's hard to control the quality of the result on this one. The 43 was about impossible enough for me, so I'll just stick with it for now. At some point my goal is to replace with a macro anyway, and if I could ever find any tubes to use they would be on my list too.

Thanks again though. Cheers, Greg
12-05-2007, 04:13 AM   #4
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Greg, I picked up a set of Vivitar k mount extension tubes on Ebay last year for $30. They really increase the magnification on my Sigma 105 f2.8 1:1 macro and work great on the 43mm. Cheap, easy and IMO much better way to spend your money.

12-05-2007, 04:39 AM   #5
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Were they the PK/A versions? That's what I'm trying to find. Not for auto focus, but for auto exposure purposes. That way it will at least assist me in getting quicker exposures.
12-05-2007, 06:20 AM   #6
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I thought Dave's reversed 31mm photos were really well done. I think its just the jpeg compression artifacts that really spoil the crispness.

I've always had high magnification and tack sharp images with reverse rings not to mention the bokeh rolls off into cream fairly fast. The only problem was that the DOF was really thin and given that the focal point is relatively fixed, you gotta move the camera. Since you have to use stop down metering, its hard to stop down without moving the camera too much/keep it steady/keep subject in DOF.


Taken w/ Reversed 18-55mm Kit Lens @ 18mm, f22 (Aperture unavoidable lol)

Last edited by FotoPete; 12-05-2007 at 01:56 PM. Reason: grammar lol
12-05-2007, 06:44 AM   #7
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Good point FotoPete. The jpeg artifacts are probably what turned me off from trying it, although also the cost of buying 3 or 4 rings. I probably just need to experiment some more with the 43 reversed before passing judgement. Seems to work really well for flat, less 3 dimensional items, so maybe subject selection is also key when using the lenses reversed.

Thanks again to all, especially David for posting the results.

greg
12-05-2007, 07:18 AM   #8
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Well... maybe repost them at a much lower compression? I've rarely seen JPEG artifects make a photo so horrible...

12-05-2007, 08:16 AM   #9
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QuoteOriginally posted by txbonds Quote
Were they the PK/A versions? That's what I'm trying to find. Not for auto focus, but for auto exposure purposes. That way it will at least assist me in getting quicker exposures.
The Vivitar set I have has the aperture lever so you basically use them like an M lens in Manual mode. There are no electrical contacts on the tubes. So focus wide open, stop the lens down and take an exposure reading. I've found the exposures accurate, it's just a little slower than using a dedicated lens but with some practice they work well.

Maybe FotoPete's example is why I never liked my reversed results. This was back when I had an LX with a 50mm attached. Tried it for a week or 2 and decided fairly quickly to buy a 100mm f4 1:2 which was a much nicer experience. I was trying to do the same thing as David and shoot flowers and so on. Too much depth in the subject and too little DOF in the reversed lens. Plus a bugger to focus, even more so using a tripod.

A flat field subject may look ok but anything with a lot of depth just wasn't that good in my experience. I still carry the 49mm ring in the bag so in a pinch I might use it. But it hasn't been used in years. Maybe I should try it again on the DSLR.

What doesn't make too much sense to me though is why would you spend $20-25 per ring for 4-5 different lenses when the Tamron 90 or Sigma 105 versions cost around $350.00? Or you could get an older SMC M100mm f4 for less than $150.00 They will give you auto/manual everything with better results and add another mid length tele to the bag that is razor sharp.

Last edited by Peter Zack; 12-05-2007 at 08:27 AM.
12-05-2007, 10:02 AM   #10
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I agree Peter, which is why I take a moment of pause on buying a bunch of additional rings and reverse adapters. The one $9.95 investment (or whatever it cost) in the one for the 49mm reverse adapter seemed to be a fun investment to play with the 43. I really didn't intend to take it beyond that, but curiosity had me wondering.

Probably best advice to simply save for a future macro lens.
12-05-2007, 12:31 PM   #11
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Yes to all that. The original PEF images are better than the 0 level JPEG quality small size images posted however I don't class them as very successful. I had the rings so had a play. Subject was very close to the lens and focusing, even with a Magnifier M, was quite difficult. I normally use helicoil extension and/or auto tubes or bellows with Pentax A 50mm f2.8 macro or Tamron SP DI 90mm f2.8 macro.for close up work.

I think the 31mm limited needs to be pointed in the other direction. The 43 and 77 produced better results but I wouldn't make a habit of reversing the limited lenses.

Take Care

David
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