View Full Version : Is a Tamron 28-200 lense for the k100d

Serafin 100
02-20-2007, 11:10 AM
a good all around lense for a tight budget. Have bought 2 other cameras in the last couple of months. So if I spend much more the wife will kill me while I sleep:D . This will be my first DSRL. But have used the upper end digicams for a while. Oh and I did have a D50 a while back for a couple of days but didnt like it. Thanks for any suggestions

02-20-2007, 02:18 PM
I'm not familiar with the performance of that lens, but 28mm is not very wide. There are many 18-XXXmm lens choices, but the larger the range the more likely the image quality will suffer.

02-22-2007, 03:47 PM
a good all around lense for a tight budget. Have bought 2 other cameras in the last couple of months. So if I spend much more the wife will kill me while I sleep:D . This will be my first DSRL.

I have the Tamron 18-200 Di-II (http://tamron.com/lenses/prod/18200_diII.asp) f/3.5-6.3 lens. Costs $100 more than the 28-200 Di (not Di-II) f/3.8-5.6 lens that you're referring to. I'm quite fond of the lens I have and use it as my general-purpose lens, in other words, its the lens that is on the camera most of the time. Takes pretty good pictures, I'm happy with it. I have no experience with the 28-200, but I have several other Tamron lenses, including the pretty inexpensive 70-300 Di. I imagine it's comparable in quality to the 28-200 that you're looking at, and I'm rather happy with the 70-300, too.

Since you mention that you're new to DSLR, remember the so-called "crop factor." When you use a lens on a digital SLR like the Pentax K100D or K10D, you don't get quite as wide a field of view as you would if you used the same lens on a film camera. This gives the impression that the image produced is at a higher zoom level, which is not technically correct. The difference, called the "crop factor," is expressed somewhat misleadingly in terms of the focal length that would produce the same FOV on a film camera, and when going from a Pentax DSLR to a 35mm film camera, that crop factor is 1.5x. In other words, a 100mm lens on a Pentax K100D produces an image that has the same field of view that you'd get on a Pentax K1000 (film camera) using a 150mm lens. Now, turning back to your problem, this means that, if you have any background with 35mm film cameras, you may think of a 28mm lens as moderately wide, but on a DSLR, it's not very wide at all - more like a 42mm lens on a film camera, that is, very close to "normal". Even the 18mm on my lens is only sorta-kinda wide (roughly = 27mm on a film camera).

What's this mean to you? Well, if you're keen to take photos of the Grand Canyon, or group photos where you get close to the group and need the width, or to photograph buildings from across the street, well, the 28 may not be wide enough in every situation. You should also understand that zoom lenses are usually not as "fast" as fixed-focal length (prime) lenses, that is, their maximum apertures are usually no larger than f/3.8 or f/4, as with these two lenses. To get a lens with a maximum aperture of f/2.8, f/1.7 or f/1.4, well, you start getting into more money pretty quickly.

But aside from that, you will find that either the 18-200 or the 28-200 lenses is quite VERSATILE. Versatility is the whole point of zoom lenses in the first place, and these two ranges will allow you to take most of the shots you'll normally want to take. As long as the lighting is satisfactory, you can use them for close-ups, long shots, indoors, outdoors, even macro. And you won't have to keep changing lenses, which is a big plus. That's why I bought the 18-200 - so I could put one lens on there and leave it there unless I have a special purpose in mind (low-light photography, etc.).

So the basic answer to your question is, YES, a lens of this sort would be a good choice. And of course the lens you're looking at is reasonably priced.

Hope this helps.


02-22-2007, 03:53 PM
I've got the Tamron 28-200 which I bought for 60 on Ebay. It is essentially the same as the Pentax as the Pentax badged one was made by Tamron. I have used the Tamron with film and digital Slr's and I find that it is a good all round lens for film but not really wide enough for digital. Another thing is that I have found with my istD that chromatic abberation can be a bit of a problem in high contrast lighting or any situation where there is a dark edge and a light background. Overall I quite like it because image quality on the whole is OK and it focusses internally so you can use a polariser without having to adjust it every time you change focus. If you can get it really cheap as I did then go for it but if you are going to have to spend more than about 100 you could get the 28-70 f4 and the 70-210 f4-5.6 which would give you better image quality.