My husband got me an EOS Rebel SL-1 with an EF-S 18-55 mm and an EF-S 55-250 mm zoom for Christmas. Now, I’m wishing that my photos of landscapes would be sharper. Our Powershot S120 with built-in [24-120 mm equivalent] lens still gives me better photos. I think I need to buy a sharper lens; a friend suggested an 18-200 mm zoom. Would that be a good idea?
It’s impossible to be certain as to the sharpness issues you have experienced, Sophia. While your zooms are not of professional calibre, their optical quality is fine. I doubt that they are the reason for your lack of satisfaction. For example, sometimes we all take photos with shallow depth of field, with some elements out-of-focus. That’s not the fault of the lens. For a more extensive range of sharp focus with any lens, try this while using a sturdy tripod, an essential accessory for testing your lenses. Compose a landscape photo. Set f/16 in the camera’s Aperture Priority (A or AV) mode; use manual focus to focus at a point about one-third of the way into the scene. Then, more of the scene will appear in focus.
Be sure to use the largest/finest JPEG Size/Quality option available. And if you use a filter, such as a UV for protection, remove it when shooting in very bright light. If you use a polarizing filter, be sure it is of high quality, with a “multi-layer” coating. (A $79 polarizer is likely to be better than one that costs $29.) Also buy the optional lens hoods for your lenses, to prevent stray light from striking the front element and causing flare.
Also, images made by most DSLRs require a bit of sharpening in software such as Photoshop Elements. Your previous camera (like most digicams with built-in lenses) may have been designed to provide stronger in-camera sharpening. If you don’t want to do sharpening with software, experiment with the in-camera Sharpness adjustment. Try shooting some photos at a +1 and a +2 level to determine which you prefer.
You seem to be looking for one lens that will meet all of your needs while providing stunning image quality. There is no such lens on the market, and, if there were, it would be prohibitively expensive. Frankly, your two zooms are probably just fine for now, unless you are ready to buy premium-grade lenses—and those would be more expensive, larger and heavier.
An 18-200 mm zoom is certainly convenient and quite affordable. However, no all-purpose zoom will provide dramatically better quality than your current lenses. Work on the technical issues, like those mentioned earlier, and you should be more satisfied with your photos. You’ll find more specifics on such aspects in Photo Life and in books, but also be sure to check out previous Q & A items.