[49 mm (Front)] I have used this lens for different applications. 
Mainly to shoot my small scale sculpture. It has the correct 
geometry to better illustrate small distances and render small
 objects with a three dimensional emphasis. 
My 100 macro is great for tiny objects (rings, coins), but it tends 
to flatten space as with any telephoto. 
The lens has great glass, and is a true bargain, with a screw drive focus. (saves on the more pricy motorized lenses). Without sacrifice of image quality. Most macro work is done hand focused on a tripod anyway. 
It is also good for portraits, and field work when you want to isolate your subject. It has a learning curve to understand the focal space is like a curtain of clarity. 
Love this lens

[APS-C] Great build quality, same for iq, tiny, very usable focal length on both apsc and 35mm. What more could you ask for? Faster aperture? Yes, it is not the fastest prime out there, but it's not that slow either and a compromise worth making given the other qualities it has.

[49 mm (Front)] I keep this lens on my camera for indoor pictures, and outdoor for landscapes and macro. I used to get frustrated w/ my 50mm when in my small house, but now I use this one so much more!

[1:1] I've wanted this lens forever and finally gifted myself. It is perfect for photographing my jewelry, flowers, and family portraits. Highly recommend.

[49 mm (Front)] I use this lens with my K50 and its basically the only lens attached to my camera now. Its a great walkaround lens that's suitable for a variety of purposes including low light photography. The macro capabilities are a nice addition. The lens is super sharp. Has beautiful bokeh and produces overall beautiful images. My only complaint would be the slower focusing especially switching from focusing something up close to something far away. Also it does struggle with low light focusing but manually adjusting the focus is very easy.

[Autofocus] Phenomenal lens, very sharp. Nice to have focus limiting too.

[Pentax K] I am a confirmed Nikon man, but purchased my K3 because neither Nikon nor Canon understand the concept of rain. Originally I bought the weatherproof K3 and an assortment of weather resistant lenses, but the more I use the Pentax, the more I like it. Sure, it may not focus as fast or as quietly as the my D800s, but it can produce some really nice work. I decided to invest in a few prime lenses for work on sunny days, and this one is very nice. It's great for general purpose wide angle work, and the minimum focus distance makes macro work a breeze. Well made and very, very sharp focus.

[1:1] And amazing little devil that is perfect and sharp from the shortest to the longest possible distance ( ie macro to landscapes).

A must have!

[49 mm (Front)] I bought this lens after reading reviews on B&H and Pentax Forums, and everything people say about its image quality/sharpness is true. The only caution to anyone buying this as a primary macro lens that if you want to take closeups of bugs or living things, the short focal length may not work for you because you have to get really close to the subject. On a tripod, shooting landscapes or city street scapes results in excellent quality images.

[f/22] I bought this lens when I bought the Pentax K-1 in November 2017.� There is a little corner vignetting in full frame mode that is easy to crop.� I use crop or square mode with no problems.� Excellent lens and camera for wildflower photos.� Good macro depth of field.