Which Pentax lens is more convenient: 55-300mm or 18-250mm??

If all things are equal, the 18-250 would probably serve a beginner better. You can crop an image shot at 250mm down to what a 300mm would have been, so you wouldnt really miss much. But if you could only go 55mm wide you'd just plain miss the 18mm range. You'd have to take two pics to get the same coverage and stitch it together in photoshop.

Neither of these lenses are "FANTASTIC" lenses if your planning on going pro (with the exception of paparazzi, image quality wont matter as long as you get the shot). Barrel distortion will make it less useful for landscapes, a non-consistant aperture will make it difficult in low light situations (just about any wedding or indoor event is a low light situation), it wont be tack sharp if you plan to print over 8x10. But if your just a casual user it should work fine.

18-250 is my vote. You may also consider the 28-300, but you'd still be missing the wider 18mm range. http://www.bhphotovideo.com/c/product/347536-REG/T...

The 55-250 is the better lens by a large margin. The 75-300 only has one rival at the bottom of the Canon line, the 28-80. The single drawback to the 55-250 is that it is an EF-S lens, meaning it can't be used on Canon full frame or film bodies. If that isn't an issue, and honestly it isn't for most people, then the 55-250 is the way to go.

The 18-250 is a good all around lens. I have the 55-300 for my Super and when I use it at times I wish I didn't have to change lenses to get the wider shot. But for the longer shots at 300mm, I'm satisfied with it for the most part (wishing for a Bigma ;)). If you don't mind changing lenses when you need wider than 55mm, get the 55-300. For the money the IQ of the 55-300 lens is pretty good.

For convenience the 18-250mm.

Zoom of 250 and 300mm doesn't make much difference but for close pictures 18 and 55mm makes lots of difference. But it is difficult to compare this lens because you didn't put the specifications because if one lens has maximum aperture greater than 3.5 (lower the number, greater the aperture) it will cost lots more.

Image stabilizer is also a very important feature to look at if you are planning to use zoom.

if both lens has the same technology I stay with the 18-250mm unless you already have a 18-55mm and don't mind to change the lens everytime

You understand that the larger the zoom the worse your image quality gets? That is the reason why you buy a dslr camera is to change lenses out. You would do better getting something around the 3-5x range.

Anyway get a 18-250 50mm at the high end will not matter. you will use under 50mm indoors all the time.

difficult call for me, it depends on what your main usage of the lens will be for. The 55-300 would be better for longer distance shooting, whereas the 18-250 will be better for closer photography, and it would have a wider angle.

(and no, you're wrong, the HIGHER the number, the more zoom it will do)

The 18-250 because you never know when you have to get in close.

you usully don't need a 10X zoom..........................you have legs,walk up to the subject........it is a lot cheaper................

you want the fastest one.........f2.8 if yu have that oprtion....

google the specific make and models with the word review..........let the pro's help you........