Which is better for sharpness: upgrade to IS or get a lens with wider aperture?

<p>I recently started shooting portraits in lower light settings and have been struggling with maintaining adequate sharpness.<br>

I currently own a Canon Rebel XT (its ISO settings are not the greatest) and typically shoot using a Canon 28-105mm f/3.5-4.5 USM II lens. It has been a great starter lens, but when shooting in lower light (even with a tripod), I get pictures that are slightly blurry and (if I have turned up the ISO to 800 or more) grainy. <br>

So, I am debating whether or not I want to sell my current lens and upgrade to a Canon EF 28-135mm f/3.5-5.6 IS USM or keep my current lens (since it has worked well for me in outdoor, well-lit portrait shots) and purchase the Canon EF 50mm f/1.8 II lens.<br>

Eventually, I would like to own both of the aforementioned lenses, but I do not have enough money to purchase them both at this time. Which option would you recommend choosing, and why?<br>

Thank you so much for you input!<br>

-Meaghan</p>

<p>For the best sharpness, a prime and tripod are the way to go. A prime will always be sharper than a zoom. The 50mm f/1.8 is a good place to start and won't cost an arm and a leg. My 50mm f/1.8 is sharper than my 17-40mm L zoom. Also, for the sharpest possible photo always use a tripod and mirror lock up. Also, use a remote or the self timer so your hand isn't actually touching the camera when the curtain raises.</p>

<p>Make sure you turn Image Stabilization off when you put the camera on a tripod. Otherwise, it sounds like your shutter speed is so slow that slight movement of your subjects during the exposure is causing the blurriness. If that's the case, you'll need to do something to speed up the shutter speed -- more light, higher ISO and/or a wider aperture.</p>

<p>A wider aperture will permit you to use a faster shutter speed, making the image much sharper. At the same time, it will permit you to shoot pictures under tougher lighting circumstances. The 50mm f/1.8 is a great lens, I own a copy myself, and I would choose it over the 28-135mm zoom anytime, due to the image quality and the low cost of it.</p>

<p>Another thing you might take into consideration is reading a bit about how to position yourself when taking a picture, in order to minimize breathing and wind movements affecting your camera while handholding it.</p>

<p>Erwin M.</p>

<p>There's no absolute answer, unfortunately.</p>

<p>First off: ultimate, tripod-mounted lens sharpness varies between lens, and between copies. Handheld, using 2 lens with roughly equal sharpness, the IS lens will win at low shutter speeds. Even if the IS lens lags slightly in sharpness, it will still win at low shutter speeds. As shutter speeds increase however, the IS advantage evaporates, and the sharper non-IS lens wins, as soon as shutter speed overcomes unsteadiness.</p>

<p>I have a f2.8 24-70 (non-IS), and a f4.0 24-105IS, and find them a perfect example of the above. Of course the 24-105 also has to overcome a one-stop disadvantage. In low light handheld, it still usually delivers sharper results, but as the light improves and shutter speeds rise, it falls behind in sharpness.</p>

<p>Ultimately, depends on your shooting style. Lots of low light favours IS. Well, except for subject motion...</p>

<p>for sharpness, suggest a prime. for portraits there is little need for zooming, so primes get the nod in that respect as well.</p>

<p>to get all the IQ the lens can deliver a hood is a good idea.</p>

<p>tripod use has a technique. turn off IS, use timer shutter release (tripping shutter by pressing release causes vibration/blur), lock mirror up, shield the camera from wind (if any), etc.</p>

<blockquote>

<p>Also, for the sharpest possible photo always use a tripod and mirror lock up. Also, use a remote or the self timer so your hand isn't actually touching the camera when the curtain raises.</p>

</blockquote>

<p>Good advice for still life and landscapes. The MLU and self timer are not practical for her low light portraits. Maybe a tripod and remote if her subjects are posed and able to hold still.</p>

<p>I'd flip a benjamin to the store clerk for the 50 1.8. You can always sell it for $70 if you hate the darn thing. If you luck out and get a good one it should be decent at F2 and critically sharp by F2.8. I've owned 3 and all were terrible wide open, okay at F2.8 and very sharp at F5.6. I could never get reliable focus in low light so practice your MF skills.</p>

<p>The EF-s 17-55 2.8 IS USM is probably your best bet if a fist full of benjamins falls in your lap: sharp at F2.8, 3 stop IS, great AF and a useful general purpose zoom range.</p>

Meaghan,

If you are already using a tripod then the IS won't necessarily help. The IS is primarily for "Hand Held" shots and often will create problems when trying to use IS when mounted on a tripod. So with that said . . .

 

"Which is better for sharpness: upgrade to IS or get a lens with wider aperture?"

 

Go for the wider aperture.

 

Are you using any sort of Shutter Button Remote when using the tripod? Maybe you are creating movement when you depress the Shutter Button. Have you tried using the Self Timer Shutter Release?

 

There are many techniques that can be attempted with the equipment you already have to produce "sharper images." You may have to refer back to, and study your User's Manual that came with your camera. It is a great quick resource and will point out the "features" and how to use them on your XT, along with the great help you can get from the forums here on PN!

 

Try the Self Timer, then maybe check and read to see if he XT has "Mirror Lockup" and if so, how to use it, etc., etc., the 28-105mm lens(es) can produce some good portraits. You could have some "back focusing" stuff going on inside the XT, but I doubt it, and I would try the other alternatives first.

 

My .02 worth,

Best Wishes,

Jim J.

<p>for portraits you might want to use faster shutter speed anyway. it's tough for a subject to sit perfectly still.</p>

<p>a fast prime close to wide open is probably the way to go as opposed to tripod use and long shutter speeds</p>

<p>I have the 28-135 is usm you are in question about, I will tell you that other than helping with the extra light that an IS lens gives you, the IS is not worth a mass amount, of course if you use an IS lens you are not suppose to shoot on a tripod without turning off the IS ,as it will eventually damage the lens or so they say. It is a very nice lens for the money. The sharpness is in you the shooter in most cases. I suggest you by a tripod, SUNPAK is a semi pro grade sold at best buy for about 80 bucks and it has a mono pod for you to use and pack around to help with the camera shake you will get from time to time. The aperture of 3:5 on that lens is fairly good , but if you can afford to come up with a lens that is 1.8 or 2.8 you will do much better with shots and the IS will not be needed, The Canon lens 50mm fixed has low light ability and you can get very sharp shots with it and it cost about a 120 bucks, I have found that in 99 percent of every shot you shoot that lighting is the key to every shot and that will go a long way with sharper pictures.SO if i were going to buy a lens for portrait shots being your objective , go with the 50mm I have it and it works like a million bucks, you really can shoot in almost no light without blur, it seems to perform best at 2.8 the lens will got o 1.8 but then you get vignetted photos, selling your lens is not what i would do, it always nice to have backups and a assortment, every lens has some purpose, or use that you will run across, If you have any credit ability , this is what I do , Walmart has 12 months same as cash and , to my amazement they carry a large assortment of Canon ef lens and they have been cheaper than any other source i have seen , in most case a 100 bucks cheaper, so i order form them and they ship FedEx for cents and i get a new lens interest fee. I have now acquired over a dozen lens from them, Take your camera to a camera shop slap a 50mm lens low end and the 28-135 and shoot several shots with each lens then go home put them on the PC and see what you think, i have tons of examples, email me and ill share out pictures that have been taken with both lens. HOPE THIS HELPS.</p>

<p>Before buying any lens, you need to figure out the cause of the blurriness. It could be hand holding shake, subject motion or misfocus, or any combination thereof. The fact that you use a tripod kind of rules out hand holding shake, but also be sure you don't have IS on when on the tripodl--that could cause blurriness, not reduce it. Also that vibration from the shutter isn't causing your camera to bounce on the tripod. In any case, you should also know the hand holding guidelines and know your limits.</p>

<p>If you are using an automated exposure system, are you watching the shutter speeds you are getting? Below about 1/60th, a human being may not be completely sharp when you view the resulting image at 100 percent magnification--due to movement, such as breathing.</p>

<p>The lens could be misfocusing (I should say the lens/camera). Double check your focusing technique. When checking for misfocus in an image, look for an area of sharp focus. If you can find one, and it's not where you wanted it, that usually means you have misfocus. Whether that is a technical problem with the lens or camera or with your focusing technique is something you need to find out.</p>

<p>Unfortunately, just buying, say, a prime lens because a prime lens is generally sharper than zooms and generally faster than zooms, does not mean your problem will be solved. First, you can't solve your problem without knowing what it is. Second, for instance, shooting a portrait at f1.8 with your 50mm may help in keeping the ISO down and the shutter speed up, but you aren't going to get the needed sharpness on the depth of a person's face (head and shoulders or close-up) at that aperture. One eye may be in focus and that's it.</p>

<p>About the 'graininess'--don't underexpose. If you underexpose and have to pull the exposure up in post processing, you will make the appearance of noise worse. ISO 800 should be OK with your camera if you take care not to underexpose.</p>

<p>The 28-105mm is a decent lens, particularly at the medium apertures. Used wide open it will compare poorly to the 50mm f1.8. After you have figured out the cause of your problem, I'd recommend the 50mm in any case, and if you are interested in a more than decent zoom, try the Tamron 17-50mm f2.8.</p>

<p>The optical quality of the 28-105 and the 28-135 is in the same league. If you expect a real improvement and you want to have a zoom, then you should consider the 24-70L or 24-105L. However, those are much more expensive. Therefore, if you are on a budget, you probably should try the 50/1.8 first and see if it delivers the sharpness you need.</p>

<p>It depends on the problem - if it is camera shake then IS may be the way to go. However, it might be a focus issue or subject motion. What are the typical settings you are shooting at when you have the issues (ISO, lens focal length, Aperture and shutter speed)</p>