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01-07-2007, 10:29 PM   #1
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"macro" feature of Tamron 18-200 lens

I've now purchased the Tamron 18-200mm Di-II "macro" lens and am using it as the default lens on my K100D. I like the lens. I cannot say that it is obviously better than the two Pentax lenses (the kit 18-55 and the 50-200) that it's replacing, but it's no worse, might be a little better, and it's a lot more convenient.

But I'm wondering about a couple of things.

First, what does it mean to say that this is a "macro" lens? I know that macro means very close up photography, say, for photographing insects or flowers or rare postage stamps. But how do I use this capability of the lens? Is it simply a matter of using the telephoto capability while getting close to the subject? I don't see a button or anything else on the lens that turns "on" (so to speak) the macro capability. I'm sort of expecting that as, with my old Canon PowerShot S3 IS, you did have to change a setting in the camera in order to access the macro capability. Is this lens capable of doing close-up pictures any better than one of the Pentax lenses I mentioned above?

Second, if it is just a matter of getting closer to the subject, how close can I get? On my Canon S3, I could get so close the end of the lens was practically touching the subject. I gather that's not the case with this lens, but I'm not sure.

Third and finally, there's a "Lock" button on the barrel of this lens. What's it for? I have sort of figured out that, if I engage the lock, I can't change the zoom and perhaps not change the focus if I'm using manual focus. What I can't figure out is where I would want to use this feature.

Just so you know, there is a little user's guide inside the box the lens came in, but it's all in Japanese, which, alas, I do not read.

Will


Last edited by WMBP; 01-07-2007 at 10:32 PM. Reason: originally linked to product page on sigma4less.com; changed link to tamron.com
01-07-2007, 10:42 PM   #2
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After posting my questions a little while ago, it occurred to me that I should look at Tamron's web site and see what info I could find there. Good idea: I found this article about macro photography and it mentions my lens specifically. This pretty much answers my first question. I understand now that I just get close to the subject and focus away.

But I'm still wondering about my other two questions (how close can I get, and what's the "Lock" really for?). And now I have a new question: It looks like my lens provides 1:3.7 magnification at this range. What about at long range? Somewhere else on Tamron's site I saw a note that said this lens has an 11x magnification. Which is it? 3.7 or 11? I know that I'm missing something important here. I'm just not sure what.

Thanks,

Will
01-07-2007, 11:09 PM   #3
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Hey Will,

I think you are right in your assumption about the lock - so you don't lose setting as you focus. Funny that my sales rep at my store said you use it when storing the lens.

You refered to 11x magnification - this is the focal length magnification (200 / 18 = approx. 11).

To explain the macro magnification, I have a tough time explaining myself. In your case (according to Tamron's website) 200mm at the minimum focus distance of 45cm (about 17.6 inches?) the macro magnification is 1:3.7, means that a 1 inch subject would take 3.7 inches on your CCD/sensor. So the 1" subject is bigger than your ccd so your viewfinder should be full!. I know someone will correct me if I'm wrong
01-07-2007, 11:15 PM   #4
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it sez on the tamron website min focus distance is 17.7 inches......
so thats as close as ur gonna get...
and the macro is 1:3 so it's not quite lifesize..but close...

as for the lock..that will probably enable the macro focusing. going with my sigma lens...i have to toggle a switch to lock it at 80mm then it will focus up close...

so it's probably a similar feature....

here's a rough idea.....did some sample shots to show a friend some stuff behind photography...


macro focused 1:2 (sigma 28-80mm shot at 80mm macro on)




the actual size of the toy



and now the distance of the camera to the toy



here's one done with a 1:3 (sigma 28mm lens)



set up to that shot



dont know if that helps you clarify your questions..hopefully it gave you a rough idea..(or i probably just confused you more... LoL)

01-07-2007, 11:18 PM   #5
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QuoteOriginally posted by Alvin Quote
Hey Will,

I think you are right in your assumption about the lock - so you don't lose setting as you focus. Funny that my sales rep at my store said you use it when storing the lens.
Oh, well, I guess you could use it that way, too. :-)

I'm just wondering - why would I worry about locking the zoom as I focus? I don't worry about it with other lenses, after all. And the zoom adjustment ring or whatever you call it on the Tamron 18-200 is fairly "tight" (meaning that it doesn't slide as smoothly as the Pentax lenses I've got), so I don't think it's going to slide out of zoom on its own.


QuoteQuote:
You refered to 11x magnification - this is the focal length magnification (200 / 18 = approx. 11).
Ah, I see. Makes sense. So it's 11x from the widest angle to the farthest zoom. I wonder if that's what was meant by Canon when it described the lens on my old PowerShot S3 IS as "12x". I always assumed it was something like the magnification number on my binoculars. Apparently not.


QuoteQuote:
To explain the macro magnification, I have a tough time explaining myself. In your case (according to Tamron's website) 200mm at the minimum focus distance of 45cm (about 17.6 inches?) the macro magnification is 1:3.7, means that a 1 inch subject would take 3.7 inches on your CCD/sensor. So the 1" subject is bigger than your ccd so your viewfinder should be full!. I know someone will correct me if I'm wrong
Hmmm. I am following you here, but is it possible that you've got the numbers backwards? I'm thinking that it's more likely that a 3.7 inch insect will be represented by 1" on my sensor. In other words, when they say "1:3.7", I suspect they're describing the ratio of the size of the captured image to the live original, not the other way round. Make sense?

Thanks,

Will
01-07-2007, 11:22 PM   #6
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QuoteOriginally posted by -=JoN=- Quote
it sez on the tamron website min focus distance is 17.7 inches......
Missed that bit of info. Thanks for pointing it out.


QuoteQuote:
as for the lock..that will probably enable the macro focusing. going with my sigma lens...i have to toggle a switch to lock it at 80mm then it will focus up close...

so it's probably a similar feature....
So I should enable that lock in order to shoot macro? I'll try that.


QuoteQuote:
dont know if that helps you clarify your questions..hopefully it gave you a rough idea..(or i probably just confused you more...
Very helpful indeed, thank you much. The pictures were also very helpful and I appreciate your taking the time to share them. I will try to find some time tomorrow to test this out.

Will
01-07-2007, 11:47 PM   #7
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Jon - nice shot of Jazz/Meister. Wait a sec. 28-80? That looks like the Pentax powerzoom in the first shot, then you switched to a Sigma in the last shot. LOL.
01-08-2007, 12:04 AM   #8
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QuoteQuote:
So I should enable that lock in order to shoot macro? I'll try that.
try....my sigma's focus range numbers has 2 colours, one for none macro..and another for macro....if it's not in macro mode....the focus ring will only spin up to a certain point, then if you turn on macro, it will go all the way to the min focus range.....or it could just be to lock the lens..(actually thinking about it, i talked w/ tamron's reps 2 years ago in the photo expo, and the lock feature was to lock the lens at it's smallest form factor so it doesnt zoom by itself like lets say when it's hanging off of your shoulders...)

my sigma 70-210 has no lock or macro switch..it focus up close when im at the max focal length (210mm) and it will only macro focus at that length (also 1:3)

QuoteQuote:
Very helpful indeed, thank you much. The pictures were also very helpful and I appreciate your taking the time to share them. I will try to find some time tomorrow to test this out.
I already had them online..so it was no big deal.....just trying to help out...

QuoteQuote:
Jon - nice shot of Jazz/Meister. Wait a sec. 28-80? That looks like the Pentax powerzoom in the first shot, then you switched to a Sigma in the last shot. LOL.
thanks....

those were both sigma's...

here's a pic i found online..(canon mount tho, but practically looks the same)

http://members.telering.at/christian.reichenauer/sig28-80macro.jpg

i've had that lens since 1999....(replaced the kit lens that came w/ my zx-50, which i also still have, but it's in really really bad shape...both lens AND body...LoL)

01-08-2007, 07:11 AM   #9
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the lock is purely to stop the barrel drooping when u carry the camera about

unlike some sigma lenses there us no marco restiction or lens setting.. no need to set macro on the camera eiither..

a tamron macro.. lens on its own



macro with x 4 hoya close-up on the end..



1:1 means means an image the same size as the sensor.. it would have been 35mm wide with film about 24mm wide with our digital.. the tamron is 1:3.7 so think a frame fill just under four inches wide.. anything under 1:4 gets called a macro lens thow..

the watch gives some idea if image size

trog

Last edited by trog100; 01-08-2007 at 08:44 AM.
01-08-2007, 08:35 AM   #10
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this is better example of the 18 x 200 macro.. at 17 inches 200mm focal lengh this is what u would get at 1:3.7

as a rough guide a true 1:1 would give about one inch.. 1:2 two inches and so on..

a hoya close up filter set works nicely if u want to get closer..

it also works on the 28 x 80 1:2 sigma..

trog

ps.. the 17 inches isnt measured from the end of the lens by the way its measured from the sensor.. which puts u a lot closer to the subject than u think..

Last edited by trog100; 01-08-2007 at 08:41 AM.
01-08-2007, 09:07 AM   #11
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Only one end of the lens has the macro capability; usually the long end (200mm). The lock holds this zoom position and it's important that it does. In the 200mm position the internal arrangement of lens elements occupies the greatest space. To focus at macro subject distance the motion of internal elements uses this maximum space. At any other focal length those internal elements collide, risking internal damage as the AF motors slam the elements together seeking correct focus. Or in manual focus as the user attempt to twist the focus ring to the extreme close-up focus at other than full focal length. EDIT: The lock prevents both AF motors and manual users from reaching the extra focus distance when the lens is at some focal length other than maximum.

Last edited by jfdavis58; 01-08-2007 at 09:22 AM. Reason: further clarification
01-08-2007, 09:10 AM   #12
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QuoteOriginally posted by jfdavis58 Quote
Only one end of the lens has the macro capability; usually the long end (200mm). The lock holds this zoom position and it's important that it does. In the 200mm position the internal arrangement of lens elements occupies the greatest space. To focus at macro subject distance the motion of internal elements uses this maximum space. At any other focal length those internal elements collide, risking internal damage as the AF motors slam the elements together seeking correct focus. Or in manual focus as the user attempt to twist the focus ring to the extreme close-up focus at other than full focal length.
Ah, VERY helpful tidbit, this. Thanks.

Will
01-08-2007, 09:27 AM   #13
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QuoteOriginally posted by WMBP Quote
So it's 11x from the widest angle to the farthest zoom. I wonder if that's what was meant by Canon when it described the lens on my old PowerShot S3 IS as "12x". I always assumed it was something like the magnification number on my binoculars. Apparently not.
Will, that's exactly what they mean by the Nx on p&s cameras and camcorders, at least related to the 'optical zoom'. 'Digital zoom' is a bit fuzzier.
01-08-2007, 10:08 AM   #14
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I said:

QuoteOriginally posted by WMBP Quote
So it's 11x from the widest angle to the farthest zoom. I wonder if that's what was meant by Canon when it described the lens on my old PowerShot S3 IS as "12x". I always assumed it was something like the magnification number on my binoculars. Apparently not.
And Beth replied:

QuoteOriginally posted by bdavis Quote
Will, that's exactly what they mean by the Nx on p&s cameras and camcorders, at least related to the 'optical zoom'.
Beth, could you clarify, please? There's a bit of ambiguity there in the hand-off from my statement to yours. What I'm wondering is, which of the two possible interpretations of "12x" did you mean by "THAT"?
  1. Is the S3's "12x" meant to refer to the entire zoom range from wide to tele?
  2. Or does it simply tell me about the power of the telephoto zoom?
Will
01-08-2007, 11:29 AM   #15
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Hi Will
Usually when you see _X optical zoom, on a p&s camera it means that the the longes focal length is _times the shortest focal length. Say for instance that you have a fancy p&s that says it has a 12X optical zoom. Chances are that it would have something like a 18mm to 216mm (in dslr terms) zoom lens. (12 x 18 = 216) It is NOT comparable to the ratings of binoculars which IIRC give a direct magnification number. If I remember my binocular terminology, a 12x pair of binoculars means that the object is twelve times larger than it would appear to the unaided eye. Not the same with cameras, there the 12X refers to a ratio between the shortest and longest focal lengths.

NaCl(hope that helps)H2O
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