KentG

Lens coatings do not "wear away" over time. The best factory coatings can't even be scratched with a knife so unless your cloth is impregnated with some kind of natural crystal (from sand to...

Me, too. I will likely be forced to buy the lens in Canon mount just to be able to use one. Kent Gittings

Its called a Flycatcher but obviously that one's taste runs to bees and wasps as well. Nice "catch". Kent Gittings

Nice shot. I looked for one of the Sigma 180/2.8 Macros for years but never found one I could buy in time. Someone always beat me to it no matter what brand of system I was shooting at the time....

One reason I have stuck with the Sigma 100-300/4 that I have is because at 300mm, while it can't match the corner sharpness of any of the Pentax 300mm primes until at least F8, wide open it is...

With more magnification the panning speed can be slower due to distance, but then image scale is no longer your friend. Plus the reduced FOV makes it hard to keep the subject anywhere in the view...

You need to read how-to BIF articles from Art Morris (Birds as Art). The longest lens that can comfortably be used hand held for shooting BIF with a FF camera is a 400/5.6. That takes into account...

An approved hack would be nice, but unlikely. Too bad Pentax does not have a company like Magic Lantern to reverse engineer their stuff and open new uses like Canon does. Of course Canon hates ML,...

I think I would have figured out your post quicker, Ron, if you had said "in screwdrive use" instead of "in screwmount use". :-) Kent Gittings

The key thing on overlapping zooms is which one is better in the overlap range. The only time you use the lens which is inferior in that range is when you don't have the time or opportunity to swap...

The Sigma 50/2.8 is an alternative. A 50mm lens makes a good 75mm portrait lens with the crop factor. But for real macro use it has one drawback, and that is the working distance. It is just too...

I have not used the Tamron but I have used a few of the Sigma 70-200/2.8 over the years doing lots of things similar like indoor soccer. I had no problem using that. I would also not vote for the...

I used to prefer an F2.8 lens on a large APS-C body because I used to do the same in my film days with large film bodies, meaning a VG was always installed. Now I am downsizing at least my Pentax...

The term goes back to the early days of PCs.  I may not have the term exactly correct but what it it means is the engineers, test equipment, and the thing you are reverse engineering are put in a...

The Sigma is slightly sharper in the photo. especially in the small scale detail. Also it looks like both were not exactly parallel to the wall as both have some areas that are sharper than the...

It should be shorter but the front lens of a 500/4.5 is almost exactly the same size as a 300/2.8. Most have a front filter size of from 105-112mm. I remember my old Sigma 1000/8 APO had a front...

It comes from almost 50 years of photography, the majority of it with Pentax. Photographers who know the value of expensive lenses will buy them regardless to be able to do what they want to...

I have or have owned both. Both are too long for portraits, at least real head shot type portraits. They have shallow enough DOF to be used outdoors as crowd portrait lenses. But for in close head...

Too bad they don't make the Sigma 105/2.8 EX DG OS HSM in Pentax. From reviews it appears to have nearly the same high bokeh as the Pentax but is sharper at F2.8 and F4 than the Pentax. I'm still...

Ditto on that. I figure the only way I will get a Sigma 120-300 is if I buy it for my Canon system. Then I could sell my Canon mount Sigma 100-300/4 and Tokina 300/2.8 to help offset the cost. I...