Go Back   Steve's Digicams Forums > Digital SLR and Interchangeable Lens Cameras > Pentax / Samsung dSLR, K Mount Mirrorless

Reply
 
Thread Tools Search this Thread
Old Jun 21, 2006, 12:24 AM   #1
Senior Member
 
Illuminati's Avatar
 
Join Date: May 2006
Location: California, USA
Posts: 583
Default

I'm tired of shaming myself for using a cheapo macro lens attachment and want to buy a legitimate but affordable zoom lens. My local camera shop doesn't carry any Pentax-compatible lenses, so I'm forced to shop online.

This Tamron lens caught my eye: http://www.buydig.com/shop/product.aspx?sku=TM28200XRPA
The 1.5 magnification from my *ist DS should allow this lens to serve me at 300mm. Does anyone have any experience or opinions about this lens?

Should I consider getting the 28-300mm model instead (it is $39 more than the 28-200mm)? I'm only considering the 28-200mm for the price. Here is the details about the 28-300mm model: http://www.buydig.com/shop/product.aspx?sku=TM28300XRPA

Thanks in advance
Illuminati is offline   Reply With Quote
Sponsored Links
Old Jun 21, 2006, 12:38 AM   #2
Senior Member
 
meanstreak's Avatar
 
Join Date: Mar 2006
Posts: 1,234
Default

Illuminati wrote:
Quote:
I'm tired of shaming myself for using a cheapo macro lens attachment and want to buy a legitimate but affordable zoom lens. My local camera shop doesn't carry any Pentax-compatible lenses, so I'm forced to shop online.

This Tamron lens caught my eye: http://www.buydig.com/shop/product.aspx?sku=TM28200XRPA
The 1.5 magnification from my *ist DS should allow this lens to serve me at 300mm. Does anyone have any experience or opinions about this lens?

Should I consider getting the 28-300mm model instead (it is $39 more than the 28-200mm)? I'm only considering the 28-200mm for the price. Here is the details about the 28-300mm model: http://www.buydig.com/shop/product.aspx?sku=TM28300XRPA

Thanks in advance
A bunch of us have it over in the KM / Sony forum. Most of us like it, especially for the price. There is a newer model and it's about double in price, but no significant difference. It's a terrific walk-around lens.... not as sharp at 4.0 or wider, but it does a good job overall.
meanstreak is offline   Reply With Quote
Old Jun 21, 2006, 12:53 AM   #3
Senior Member
 
Illuminati's Avatar
 
Join Date: May 2006
Location: California, USA
Posts: 583
Default

Thanks for the quick response!

Would you recommend I bite the cost/weight/quality bullet and get the 300mm instead of the 200mm? I'm wondering what I can do with the 200mm lens, and if the added distance of the 300mm lens is worth the extra $39.
Illuminati is offline   Reply With Quote
Old Jun 21, 2006, 6:20 AM   #4
TDN
Senior Member
 
TDN's Avatar
 
Join Date: Jun 2006
Posts: 1,288
Default

Well since you're going for macro, I would suggest you take the 300mm

If you look at the specs, the 28-300 has a 1:2.9 magnification ratio, compared to the 1:4 of the 28-200.

On your digital you'll even have a little better macro performance, so it'll be close to 1:2

I'm no expert, but I'd go for the 28-300

There are people on here that know a lot more about this stuff than me, so they'll probably help you out much better

TDN
TDN is offline   Reply With Quote
Old Jun 21, 2006, 8:21 AM   #5
Senior Member
 
nlp239's Avatar
 
Join Date: Jan 2005
Posts: 719
Default

All this 'true' macro against zoom-macro is confusing this ole man can anyone explain to point me somewhere EASY to understand.

As is this thing aboutthe ratios of 1:1, 1:2, 1:10 etc.

Thanks
nlp239 is offline   Reply With Quote
Old Jun 21, 2006, 10:54 AM   #6
TDN
Senior Member
 
TDN's Avatar
 
Join Date: Jun 2006
Posts: 1,288
Default

Well, those thing are measured in comparison to the size of classic 36mm film.

For example, 1:1 means that something you shoot will have the exact same size on the film as in reality. When the film is developed and printed on a larger format, this'll give you a pretty nice magnification.

1:2 means that it is half the size on the film compared to in reality. (thus: 1/2)
1:3 -> one third of the real size. etc...

Some ebayers put 1.1 in their auctions, and then quote the lens to be a macro lens, but 1.1 (notice the "." instead of ":") actually means 1:10, which means something you shoot will be 10 times smaller on the film than in reality, and so not really providing any real "macro"


Now since digital sensors are a little smaller than 36 mm film, the macro ratio is actually a little better than stated on the lens. (they're 24mm, so "36mm equivalent" is 24x1.5=36mm, that's why you can add half the focal length of lenses when used on a DSLR)
So 1:3 will actually be closer to 1:2 (do the math, 1:3 + 1:6 (half of 1:3) = 3:6 = 1:2)

Hope this answers your question.

TDN
TDN is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 7:56 AM.