View Full Version : Pentax F 28-80 Macro VS Sigma 28-80 Macro VS Sigma 28-90 Macro

09-08-2013, 10:50pm

Not everyone is ready to drop a lot of $ on a Dedicated macro lens , or one of those (now) collectible Pentax Macro Lenses ...
Well Ive always been some what cheap at heart , and also some what inquisitive , so I thought I would check out the cheaper end of the scale so to speak , and pick up some of the more affordable contenders that may be suitable as an entry level lens to macro photography :

Now they did have to be auto focus , affordable , and relatively easy to find ( plentiful ) and not something considered a collectors item ! ( Big No No )
The budget cap for this exercise was $50 , and all the lenses here came under that ..

Sigma 28-90 Macro

This is my 2nd copy , the first refused to work on any body but one 35mm (http://www.bhphotovideo.com/c/search?Ntt=35mm&N=0&InitialSearch=yes/DFF/d30-v1-t9/DFFInline=regex) , and only 33% of the time , that lens got hammered (http://www.pentaxforums.com/forums/pentax-slr-lens-discussion/218786-warning-explicit-images-lens-violence.html#post2316937) ! But lets move past that .

The 28-90 Macro has a plastic mount , and some of these lenses may have issue working , so buying might ( might ) be risky ...


Now I haven't had much time with this lens , but here is a sample Macro shot of a fly ...

Now these next shots are going to be of the focus distance ( Minimum )

First image is at 28mm , and is as close as I can get and still Auto Focus .


The next image is at 90mm , and again as close as I can get with Auto Focus .


This one is Macro , and as close as I can get with Auto Focus .


And the last one is a cropped 2:1 ( 2000px : 1000px )


Pentax F 28-80 Macro

Sample Macro shot :


First one is 28mm (http://www.bhphotovideo.com/c/search?Ntt=28mm&N=0&InitialSearch=yes/DFF/d30-v1-t9/DFFInline=regex) and as close as I can get with Auto Focus .


Next one is at 80mm and as close as the Auto Focus will allow


Next one is the Maximum Macro and as close as the Auto Focus will allow


This one is a 2:1 crop


Sigma 28-80 Macro

Sample Macro shot :


First image is at 28mm and as close as the Auto Focus will allow


Next image is at 80mm and as close as the Auto Focus will allow


Next one is Macro , and as close as the Auto Focus will allow


Next one is a 2:1 crop


Lets talk a little about the Lenses:

Sigma 28-90 > This lens has the plastic mount , and as near as I can tell a bit of a rep for not working 100% with digital cameras ( True or false ? ) , all I know is I had a bad one and it got hammered hard . Now other than that , this 2nd lens works rather well so far ,
Function : There is a little switch on the side of the body , Normal and Macro .
You need to crank the lens to max magnification , in this case 90mm (http://www.pentaxforums.com/reviews/tamron-90mm-macro-vs-pentax-100mm-wr/introduction.html?src=al) , then you can switch to Macro mode .. To get out of Macro mode , you need to focus the lens on a object far enough away so the lens is not in the Macro range .
What I like about this lens is , even though you are in Macro , you can still focus to infinite ..

Pentax F 28-80 > This is quite a substantial lens ( weight ) . To enter into macro mode you just twist the zoom into the Macro range , now here the lens gets interesting . The Macro focus range is small , very small , in fact you need to teak the focus manually to be within the focus range ( for distance ) .. The lens does not Automatically focus through the entire Macro range , it needs user assistance or input ( manual focus ) . The other thing is once in Macro mode there is no infinite focus , you are stuck within the very limited Macro focus range .. ( I hope I have explained this well ? )

The other thing , which I dont know is normal or not , this is a very clunky lens .. What I mean by that is when the lens comes into focus it does so with a very audible clunk http://www.pentaxforums.com/forums/images/smilies/eek.png , I dont know what to make of that ...
Also the focus distance is on the long side for a Macro lens ( Distance to subject )

Sigma 28-80 > I have had the longest exposure to this lens ( within this trio ) , and it has proven to be a capable Macro lens for the $ Paid ..
This one is has a Metal mount ( apparently there is a Plastic mount version out there ) , and has proven to be durable and capable ( Macro ) .. Where this lens lets down is when used as an ordinary lens and especially from medium to longer distances .. Images are soft to downright soft if not in fact out of focus at times .
When not used as a Macro lens , this lens has over several months proven to be quite ordinary , worth every penny of the $40 paid ( 35mm Body lens combo ) . You simply can not compare this lens to ones costing a lot more , its just not fair , but its in Macro mode that the lens comes to life . Its not going to take commercial quality Macro images , what it will do is take decent macro images that will teach you a lot about macro photography . So once you learn how to take a decent image , then go buy a high $ ticket lens ..


If I had to draw a conclusion now ! I would say get the Sigma , but test it first to make sure it works ...

I will come back to this as time permits , as the Sigma 28-90 and Pentax F 28-80 are relatively new to me , so I just wantto run a few thousand images through each lens , before I say how good or average they may be for general use .. I did include links to the lens reviews , but I will finish this of ..

Hmmm , there are two more cheap Auto focus macro lenses out there , Cosina and Tokina ... ( ? )