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06-22-2010, 07:51 PM   #1
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Newbie question on close up lens

Hi

I am interested in buying a close up lens.
My main application will be to reduce the minimum focusing distance (not really to get a macro shot).
I am planning to get a 67mm size because I want to use it with Fa* 85mm.

I found 2 websites that have the list of close up lenses:
Currently Available 2 Element (Achromatic) Close-up Lenses
Fuzzcraft.com | A list of achromatic close-up lenses | Photography, audio and light DIY projects

From what I've gathered, the lens appropriate to my need is the Pentax T226 with +0.44 diopter or T132 with +0.76 diopter.
Another option is the Canon 500D 77mm using a step up ring.

The magnification (diopter value) should be as minimum as possible so I can keep the maximum focusing distance as far as possible.

Is this possible?
I want to know if this is workable.
Is there any other option? A better option maybe?

Any comment and suggestion is very much appreciated.

cheers
Glenn


Last edited by bodhi08; 06-22-2010 at 08:13 PM.
06-23-2010, 07:56 AM   #2
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Maybe you should ask this in the "Pentax SLR Lens Discussion" section of this forum.
06-23-2010, 09:42 AM   #3
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Yes, since this is a pretty specialist question - most people asking about close-up lenses are wanting them for more "consumer" oriented lenses with smaller filter sizes, and want high, not low diopters (not they even know those terms!) - I'm moving this to the lens forum, where I suspect you'll get better responses.

I'd also check out the newer Marumi achromats, which are available in a variety of sizes and seem very reasnably priced.
06-23-2010, 10:36 AM   #4
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I guess the question is, exactly what are you trying to achieve with the lens.

remember that the diopter is really 1/focal length, and with the close up attached, you modify the maximum focusing distance of the lens to be equal to the focal length of the close up lens. A 0.5 diopter therefore sets the maximum focusing distance to 2 meters.

06-24-2010, 10:27 AM   #5
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QuoteOriginally posted by Lowell Goudge Quote
I guess the question is, exactly what are you trying to achieve with the lens.

remember that the diopter is really 1/focal length, and with the close up attached, you modify the maximum focusing distance of the lens to be equal to the focal length of the close up lens. A 0.5 diopter therefore sets the maximum focusing distance to 2 meters.
A short answer to that is: I am trying to figure out ways to use the FA 85mm a bit more.
It is such a nice lens but because of the limited FOV on APS-C cameras, I don't find the focal length that useful. I really wish it were a 35 or 50mm

I was thinking about using extension tubes but have not tried it.

Maybe I'll just get a close up lens and use the 85mm as macro lens since I don't have any macro lens
I want to keep AF if possible, that's why I am thinking of close up lens instead of extension tube.

2 meters maximum focusing distance doesn't sound too bad. I don't need to get too close to the subject.

I am thinking about those few macro shots in a wedding situation such as the wedding ring etc. So I can basically put on the close up lens when required and take it off to take normal portraits.

Should I buy those cheap close up lens to play around with before getting the expensive ones?
Maybe the one with +1 diopter because they are easier to find compared to +.5

With higher magnification (such as +2 or +4) does it make the DOF thinner than +.5?

cheers

Last edited by bodhi08; 06-24-2010 at 10:32 AM.
06-24-2010, 01:00 PM   #6
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I wouldn't worry about keeping AF for macro - most people use and recommend manual focus anyhow for macro photography.

Yes higher magnification gives thinner DOF for the same focal length, because higher magnification is achieve through shorter distances, and shorter distance always translates into shallower DOF, diopter or no diopter.

If it's really just for the occasional wedding ring shot in the middle of a portrait session, sure, a cheap +1 diopter could be worth a shot - but frankly, I'd be more inclined to simply switch lenses to something that focuses closer on its own. Even the kit 18-55 if you have that. Or maybe get a cheap MF macro prime, or a regular prime (like a 50, since it seems you want one anyhow) with its own closeup lens (or extension tube).

Last edited by Marc Sabatella; 06-25-2010 at 08:53 AM.
06-24-2010, 03:11 PM   #7
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QuoteOriginally posted by bodhi08 Quote
A short answer to that is: I am trying to figure out ways to use the FA 85mm a bit more.
It is such a nice lens but because of the limited FOV on APS-C cameras, I don't find the focal length that useful. I really wish it were a 35 or 50mm
If the lens was working for you generally, and you just wanted to do some close-focus work, I would follow Mark's suggestion of a +1 diopter close-up lens (and upgrade to a 2-element close-up lens later if necessary).

Your FA85 by itself has a minimum focus of 0.85m; to change the maximum focus distance to 0.85m you need a close-up lens with a power of about (1/ 0.85m) = +1.2 diopter.

You also might be able to get away with a smaller-diameter close-up lens on a step-down ring (after carefully testing for vignetting and interference problems, of course)

However, since you say that the 85mm focal length is too long, it may be time to start looking for another lens (perhaps a close-focusing 35mm or 50mm or a 28-75mm/2.8 zoom).
06-25-2010, 02:28 AM   #8
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Thanks for the input.

I'll try cheap +1 to +4 diopters and see how it goes.
And I am also trying to get a second hand Raynox 150 if anyone is selling.

85mm generally works for outdoor photo shoots where there is enough room to move around to get more than just a head and shoulder portraits. And timing is not very critical.
I've had few full body portraits taken with it.
Excellent IQ, beautiful bokeh.

But a wedding is a different animal.
I am trying to use it on 2nd body instead of zoom such as DA 50-135mm.
Mainly for the speed (in a church with no flash) and (thus) the thin DOF to get more OOF area.
Not easy, but lots of fun

cheers


Last edited by bodhi08; 06-25-2010 at 02:34 AM.
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