Pentax 200mm, Sigma 180mm tests

As I now have both of these lenses I have done a few comparison shots with the Pentax A*200mm f4 macro and the Sigma DG 180mm f3.5

Basic specs are, the Sigma weighs in at 1200grms with a 72mm filter and the Pentax at 950grms with a 58mm filter,

I was a bit lazy and had the Pentax mounted on the K20 and the Sigma was on the K7, Not sure if this will make a huge difference with the comparisons, but both cameras were setup the same and mounted on tripods side by side.

These are the 2 beasties in question.
[IMG]http://i184.photobucket.com/albums/x261/ClarkyinAus/Lenses180mm200mmmacros.jpg[/IMG]

The Pentax at f6.7, The seed pods were about 4metres away from the camera, uncropped and no PP just resized for the web.
[IMG]http://i184.photobucket.com/albums/x261/ClarkyinAus/Pentax200mmf63.jpg[/IMG]
The Sigma at f6.7
[IMG]http://i184.photobucket.com/albums/x261/ClarkyinAus/Sigma180mmf67.jpg[/IMG]
The Pentax wide open at f4
[IMG]http://i184.photobucket.com/albums/x261/ClarkyinAus/Pentax200mmf4.jpg[/IMG]
The Sigma wide open at f3.5
[IMG]http://i184.photobucket.com/albums/x261/ClarkyinAus/Sigma180mmf4.jpg[/IMG]
A flower with the Pentax about 500mm away
[IMG]http://i184.photobucket.com/albums/x261/ClarkyinAus/Flower200mm-1.jpg[/IMG]
Same flower with the Sigma about 500mm away
[IMG]http://i184.photobucket.com/albums/x261/ClarkyinAus/Flower180mm.jpg[/IMG]
A couple of random shots handheld with the Pentax
[IMG]http://i184.photobucket.com/albums/x261/ClarkyinAus/Bee200mm.jpg[/IMG]
[IMG]http://i184.photobucket.com/albums/x261/ClarkyinAus/Bee200mm2.jpg[/IMG]

Overall not a great difference between the 2, I like the colours from the Pentax, I am probably not the best judge for these kind of tests, so what do you all think. :

The Pentax walks it.


Mike trundles off to have another look at the FA 200mm Macro on Ebay ....

I don't think the Pentax walks it but I would rather have the Pentax than the Sigma based on size and these images.

It's hard to tell, the two cameras are giving different exposures, probably due to the difference in metering systems. I'd take the K20D and Pentax A*200 please

Thanks guys, I wouldn't say the Pentax walks it either, I like the Pentax wide open, bokeh is better IMO, and the bee shots are amazing handheld, I don't think I would have got them as good with the Sigma.

I agree with John, that the different exposures with the two differnt cameras doesn't help with the comparisons, in reality I should switch the lenses over and re-shoot the test. any ideas on how or what I should shoot to get a definitive result, as I said running these tests is not really my go, so I will take on board any tips you may have.

Cheers.

PS when Mike gets that FA 200mm we can do some more comparisons Mike just make sure you keep enough cash for bus fare home

I think the Sigma is miles better and you should sell me the A* 200

Is anyone else surprised at the difference in exposure levels?

For me the Pentax has nicer bokeh and colour, and the smaller size would be a lot more appealing.

It's a little hard to tell much at this size but the Sigma looks sharper to me (I feel dirty saying that ).

The magnification seems odd too, the Pentax shots look much longer than the Sigma ones.

This was the last test I did - feel free to copy my methods to your heart's content buddy.

From the above I prefer the Pentax, but both of them look much nicer than that horrible Voigtlander you've got - surely it's time you found a new home for that one? I might even take it off you as a favour...

The K20D's on spot metering, the K-7 on matrix, so for the 200mm shots the K20D was metering from the dark seed pod in the centre of the image, hence the lighter shot overall.

And the flower shots were shot with and without flash, hence the dark background on the Pentax 200mm shot, and the more even lighting on the Sigma.

So, as far as comparisons go, not exactly the best set Clarky. But probably the most telling line of yours was "...the bee shots are amazing handheld, I don't think I would have got them as good with the Sigma."

Dan

Thanks for that Hefty, I don't think I could be as extensive and detailed as you, but some very good info I could use,

Sorry mate, the Voigtlander is staying put, maybe I should do a 3 lens test

Hmmm I knew I would cock it up somewhere I went over both cameras to make sure they were the same and missed the metering and the flash on the flowers, I took a few shots with and without flash and must have mixed them up. Oh well back to the drawing board. Thanks Dan.

Why not parcel the lenses up and send them off to Hefty, I'm sure he would jump at the chance to play with them, though looking at his comprehensive tests it may be a while before you get them back

I'd be willing to help out for the good of the forum - you could expect to see the results around about the year 2050...

Your too kind hefty I'll tell you what, you come and pick them up and there all yours for as long as you need them.