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04-11-2012, 05:35 AM   #1
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Macro lens?

I have a Tamron Adaptall-2 28-50mm f/3.5-4.5 lens which says macro on it, is it a true macro lens and has anyone got any experience and tips of this lens . (I am new to macro so please forgive me)

04-11-2012, 05:52 AM   #2
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QuoteOriginally posted by fourfivesix Quote
I have a Tamron Adaptall-2 28-50mm f/3.5-4.5 lens which says macro on it, is it a true macro lens and has anyone got any experience and tips of this lens . (I am new to macro so please forgive me)
I clicked the link in your post. It says Magnification Ratio 1:4 (at 50mm). Macro is generally 1:2 or greater. Also, I don't know of any zoom lens with real macro capability. But your lens is close focusing, which is useful.
04-11-2012, 07:50 AM   #3
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As noted Macro is usually considered to be 1:2 or greater. Some folks insist on 1:1. Many zooms add the word macro on the lens because the manufacturer thought it would sell better. And they were probably right. 1:4 is not true macro but is a very nice 'close focusing' ratio. Assuming the lens is sharp enough you should get good images from it, just not true 'macro'. For pictures of flowers and other moderate sized things 1:4 works just fine. For small insects or other really small things you will not be able to fill the frame.
04-11-2012, 08:46 AM   #4
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Thanks what would happen if I added a 2x converter?

04-11-2012, 09:03 AM   #5
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Lensmakers label their glass MACRO because it's sexier and uses less ink than CLOSE-FOCUS. I know of exactly one 'real' macro-zoom, the massive Schneider Betavaron 50-125 enlarger zoom. All others are just close-focus.

QuoteOriginally posted by fourfivesix Quote
Thanks what would happen if I added a 2x converter?
Images would look twice as large, so the lens would go from a maximum of 1:4 to 1:2 magnification, which *is* macro. You would also need exposures that are four times as long, because a 2x TC eats two f-stops of light.

Allow me to plug this: https://www.pentaxforums.com/forums/pentax-lens-articles/152336-cheap-macro-b...lose-work.html
04-11-2012, 09:39 AM   #6
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Try other AD-2 lens ... 103A possible

QuoteOriginally posted by fourfivesix Quote
I have a Tamron Adaptall-2 28-50mm f/3.5-4.5 lens which says macro on it, is it a true macro lens and has anyone got any experience and tips of this lens . (I am new to macro so please forgive me)

Bonjour fourfivesix,

Since you have already a PK/M or a PK/A mount, I would suggest looking at other Adaptall-2 lenses ... the "103A" Model (80-210 f3.8/ 4) is very good and very inexpensive Tamron Adaptall-2 80-210mm F/3.8-4 Model 103A

The "macro" comes in at 1:2.8 and at 1:1.4 with the "01F" 2x TC.

Check out "Rocky Cameras" Tamron , they have a lot of them ... but get a "103A" as opposed to "03A" ... plus there's lot of other options in Adaptall-2's and SP's ...like the "23A" that I have.

Allez et bon courage, John le "Brown" Baudet du Poitou
04-11-2012, 07:45 PM - 1 Like   #7
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One warning with a 2x converter is that the lens will not focus as close as the lens without it. Because you have to move further back to obtain the minimum focus distance, the image will not be as large as it would be if you used a close-up filter, extension tubes or bellows. To get better results in the macro arena, the last two are the best options for good magnification and sharpness. You still lose light because of the "bellows factor" which is dependant on the amount of extension you add between the lens and the camera body/sensor, but not as much light as a 2x converter will cause you to lose.

regards,
04-13-2012, 08:09 PM   #8
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My macro lens is my Pentax A35-105 F3.5, which I use often on my K20D. It has a very odd shift in the focus ring to allow macro focusing at all zoom ranges (35-105mm). This lens can be found quite reasonably priced on Ebay. It does basically everything well and when testing my new K1000 SE I went for a close up of the inside of a tulip with sunlight shining through the petals to light it. I was surprised to find that the tulip was actually INSIDE the lens hood I had attached when I took the picture and I could still fine focus on different parts of the interior of the flower. Needless to say I'm quite eager to see the results when I get the pics back.

Ok, just checked it with a measuring tape, may have been exaggerating slightly, minimum focus distance is 4.5" at 35mm and about 24" at 105mm, so it was just touching the petals with the lens hood when I was focused on the interior about an inch deeper.


Last edited by PPPPPP42; 04-13-2012 at 08:21 PM.
04-15-2012, 01:15 PM   #9
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There are some great macro lenses to be found on e-bay and on the marketplace here. I found mine (FA 100mm 2.8) on the marketplace here in pristine condition. When I was looking, I wanted a 100mm FL and after doing some research, the ones I ended up searching for were the F 100mm 2.8, FA 100mm 2.8, Tamron 90mm 2.8 and the Sigma 105mm 2.8.
The 50mm lengths are less expensive.
And a friend who shoots with Canon just recently purchased some Macro filters because she didn't want to invest in a macro lens; she doesn't do enough macro photography to make it worth it. Anyway, in the camera store they told her the filters let more light in than extension tubes so she went with the filters.
04-15-2012, 02:00 PM   #10
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in truth, it is not that the c\u filters let in more light, but that the extension tubes reduce the light as the extension increases. This is called bellows factor. It is very predictable. Here is an on-line calculator to determine exposure changes:

Cooksey-Talbott Gallery - Online Photographic Bellows Extension Calculator - Nature, Photograph, Photo, Gallery, Panorama, Wallpaper, Desktops, Sierra, Waterfalls, California Hills, Yosemite, Ansel Adams Wilderness, Sonora Pass, Ithaca, Trinity Alps

regards,

Last edited by BigDave; 04-15-2012 at 03:22 PM.
04-15-2012, 02:18 PM   #11
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QuoteOriginally posted by BigDave Quote
One warning with a 2x converter is that the lens will not focus as close as the lens without it. Because you have to move further back to obtain the minimum focus distance, the image will not be as large as it would be if you used a close-up filter, extension tubes or bellows. To get better results in the macro arena, the last two are the best options for good magnification and sharpness. You still lose light because of the "bellows factor" which is dependant on the amount of extension you add between the lens and the camera body/sensor, but not as much light as a 2x converter will cause you to lose.

regards,
This is somewhat misleading

A 2x teleconverter does not alter the behavior of the lens, the working distance from the front of the lens to the subject is the same. The way lenses are sometimes defined with the focusing distance being measuerd from the subject to the focusing plane does change, but only by the thickness of the TC
04-18-2012, 06:05 AM   #12
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Lowel:

OOPS, you are correct! The lens focuses about the same distance with the 2x converter, but MAN do you lose a lot of light! I tested this with a 2x converter and an extension tube (12mm), and the extension tube was the way to go. The extension tube allows for closer focusing, as mentioned, but the short extension tube did not lose much light (the 2x converter lost 2 stops, the 12mm tube, about 1/3 stop at most). We need all of this stuff in our kit!

Regards,
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