What should I look for when buying a lens?

[F1addict]

After reading what you people have said and watching countless review videos I've narrowed my camera choices down to the Canon XSi and Sony A300. But what is going to finally make my decision is how much lenses would cost for each. I've been looking around on ebay but I don't know anything about what makes a lens good or bad or what would be the standard price for them.

So if I were buying a zoom lens for the A300 for example what should I be looking for? What brands are better then others etc?
For example would this be a good lens or is it the classic scenario of the price is too good to be true? http://cgi.ebay.com/SIGMA-70-300mm-...oryZ3323QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

sorry, I know this is kind of a broad question but I didn't know how else to put it
Please help me! Because I think if I don't make a decision soon my head is going to explode because I've been thinking about this for so long

 

[Sw1tchFX]

Go to your local camera shop and see what they have, camera decisions shouldn't be made solely online.

 

[F1addict]

Go to your local camera shop and see what they have, camera decisions shouldn't be made solely online.

We have one stand alone camera shop around here. And honestly I don't like asking people in places like that or in places like best buy or other places because I don't trust what they actually know...its a long story that involves me being told many lies by sales people.

I prefer to ask people who I know actually use these types of cameras on a regular basis and know from experiance what works and what doesn't.

 

[prodigy2k7]

I have the Canon Rebel XTi and I can tell you I love my camera! I have had no problems with it. The only thing is high ISO performance isnt the best, but I dont often shoot where I need to use high ISO's.... I try not to go above 400, 800 if needed...1600 is ehh to me... XSi is newer and probably has better ISO performance than the XTi, just an assumption... Anyways, If you get the XSi, or any canon, you can use the nice line up of canon lenses, I am very happy with their lenses, A few months ago I got a 50mm F/1.4 and its amazing I will be Canon forever, or Nikon (hehe) but I will never stray from the top 2....

You do get what you pay for...

 

[Bifurcator]

For lenses you're mostly stuck with online bench tests. It's allot of searching too - or at least it has been for me. I haven't found a site that actually tests lenses like they need to be and that has more than a few lenses listed. So it's search search. You can visit the shop but that's not going to tell you anything other than that it actually fits your camera and about how fast/noisy it is and that's only if they allow customers to test - many won't - at least not in Japan. They let you play with the cameras and whatever lens happens to be attached to that tho. Still to test a lens is complicated and involved. Forum based opinions can tell you speed and noise levels sometimes but a good lens test will always tell you more than "I own lens X and it's been my trusty friend for years". So search search search...

 

[Overread]

Its not just lies in the shop you are after - its feeling the equipment. Seeing how it fits in your hands and (for lenses) most importantly how it performs with the camera and what results you get.
For some its easy to work out what kit they need with trials - for others its not.
As for a decent lens vs a cheap one I can tell you that the sigma you link is a cheap lens - it makes a lot of compramises and yet offers a decentish return - in exchange its very cheap. I rate it a good learning lens - one which offers macro, a wide focal range and thus lets you learn about these things first hand. Once you start getting your feet more you will start to understand focal lengths and what they mean as well as start developing hte skills needed to use a lens effectivly.
the sigma you link is also made for canon as well

 

[Paul M]

I hope this site helps you a bit. It not only shows various cameras and lenses, but it also shows pictures taken so you can compare and see for yourself. Please, understand this may give enough information for you to go to the store with something in mind. Even if you decide to buy online, I would say to go to the store and educate yourself on what interests you and get a hands on feel for what you are considering.

http://www.dpreview.com/

 

[Bifurcator]

Its not just lies in the shop you are after - its feeling the equipment. Seeing how it fits in your hands and (for lenses) most importantly how it performs with the camera and what results you get.
For some its easy to work out what kit they need with trials - for others its not.
As for a decent lens vs a cheap one I can tell you that the sigma you link is a cheap lens - it makes a lot of compramises and yet offers a decentish return - in exchange its very cheap.

Just for discussion sake I can't agree with that at all. How are you going to test resolving power, brightness, clarity, ca, distortion, and etc. etc. etc. and at every stop under different conditions from looking at it in a shop?

Even zoom, you're stuck with the "feeling" you get looking through the VF and that is different for every camera and not usually a very good indication of what the actual results will be like.

Many times the price of a lens is deceptive and a $250 jobber will blow away the optical qualities of an $800 dude - So price is not an excellent indicator either.

I feel the equivalent to this is kicking tires in a car lot. It might feel good on your toes but it's not going to tell you squat about the automobile. Of course you should do both but to me 95% of the weight should be placed on bench tests, 4% on in-shop experience, and 1% on user testimonials - or something close to that.

 

[Overread]

true - it does take a good month or more of proper use to get the most understanding of a lens - but I feel that renting a lens as cheap as the 70-300mm for that time period is not cost effective really - were it some thing like choosing between a 500mm and 600mm I could very well support renting.
However every little does help - of course read reviews, but if you are still unsure take a look at the lens - for starting out it at least gives and idea of what 300mm looks like (especially to the new)

 

[JustAnEngineer]

1) I'm not an expert, by any means, but I believe that you need to start out by selecting the focal length, or range of focal lengths, that you want.

The APS-C size sensor in the Sony α700 has a 1.5x field of view crop factor (same as Nikon's entry-level DSLRs). The lens usually included with the Sony α camera kits is the SAL1870 DT 18-70mm f/3.5-5.6. This covers a very useful range of focal lengths from wide angle (18 x 1.5 = equivalent field of view of a 27 mm lens on a full-frame camera) to moderate telephoto (70 x 1.5 = equivalent field of view as a 105 mm lens on a full-frame camera).

The $149 Sigma 70-300mm F4-5.6 DG Macro lens that you linked is a long telephoto zoom. This focal length range is good for bringing far away things closer. However, the 70mm minimum on this lens is a bit long for indoor shooting. You usually will not be able to back up far enough to get a person's entire body into the frame.

With a 1:2 maximum magnification (Macro), you could also use this lens to make small things look large. You could make a bug fill half the frame.

Here's a table listing Sony lens and camera compatibility:
http://esupport.sony.com/perl/news-item.pl?&news_id=193

2) Once you have decided on the focal length range that interests you most, the next most important specification is the maximum aperture. At f/3.5 at 18mm and f/5.6 at 70mm, the kit lens is not especially fast. A lens with a larger maximum aperture (e.g.: f/2.8 to f/1.4) would let you shoot with less light, and would be able to create a shallower depth of field for smooth out-of-focus backgrounds in your portraits.

3) Once you have an idea of what focal length and aperture interest you, look for reviews to find out about image quality. Here are a few:
http://www.photozone.de/Reviews/Sony%20/%20Minolta%20Lens%20Tests

Do take a look at the $420 Tamron AF 17-50mm f/2.8 XR Di II lens, to see if it appeals to you.

 

[Bifurcator]

Yeah, but what I'm saying to you can get the entire "month of use" experience plus actually allot more just from a proper bench test. Of course look at it and hold it b4 you buy even operate it if they allow it but - but - but...

 

[Bifurcator]

For example the lens mentioned originally and discussed by yourself (Overread) and

1)
The Sigma 70-300mm F4-5.6 DG Macro lens that you linked is a long telephoto zoom. This focal length range is good for bringing far away things closer. However, the 70mm minimum on this lens is a bit long for indoor shooting. You usually will not be able to back up far enough to get a person's entire body into the frame.

Would go like: http://www.photozone.de/canon-eos/326-sigma-af-70-300mm-f4-56-apo-dg-macro-test-report--review (be sure to see all pages) or maybe the wimpier: http://www.ephotozine.com/article/Sigma-70-300mm-F4-56-DG-Macro and etc.

 

[F1addict]

1) I'm not an expert, by any means, but I believe that you need to start out by selecting the focal length, or range of focal lengths, that you want.

The APS-C size sensor in the Sony α700 has a 1.5x field of view crop factor (same as Nikon's entry-level DSLRs). The lens usually included with the Sony α camera kits is the SAL1870 DT 18-70mm f/3.5-5.6. This covers a very useful range of focal lengths from wide angle (18 x 1.5 = equivalent field of view of a 27 mm lens on a full-frame camera) to moderate telephoto (70 x 1.5 = equivalent field of view as a 105 mm lens on a full-frame camera).

The $149 Sigma 70-300mm F4-5.6 DG Macro lens that you linked is a long telephoto zoom. This focal length range is good for bringing far away things closer. However, the 70mm minimum on this lens is a bit long for indoor shooting. You usually will not be able to back up far enough to get a person's entire body into the frame.

With a 1:2 maximum magnification (Macro), you could also use this lens to make small things look large. You could make a bug fill half the frame.

Here's a table listing Sony lens and camera compatibility:
http://esupport.sony.com/perl/news-item.pl?&news_id=193

2) Once you have decided on the focal length range that interests you most, the next most important specification is the maximum aperture. At f/3.5 at 18mm and f/5.6 at 70mm, the kit lens is not especially fast. A lens with a larger maximum aperture (e.g.: f/2.8 to f/1.4) would let you shoot with less light, and would be able to create a shallower depth of field for smooth out-of-focus backgrounds in your portraits.

3) Once you have an idea of what focal length and aperture interest you, look for reviews to find out about image quality. Here are a few:
http://www.photozone.de/Reviews/Sony / Minolta Lens Tests

Do take a look at the $420 Tamron AF 17-50mm f/2.8 XR Di II lens, to see if it appeals to you.

Thank you, that is all very helpful information.
That Tamron is a good $200 over my budget for a lens now. In a couple of years once I've had experiance with a DSLR and I know more about photography I'd love something like that. Althougth for now, the kit 18-70mm(for the Sony), 18-55mm (for the Canon) would be all I'd need in that range. I don't see myself needing a higher end standard lens for now.

Obviously I wouldn't use that 70-300mm Sigma for indoor shooting (which I don't do much of to begin with). Id mostly use it while at the lake or maybe at the race track. And, if I got the Sony A300, I'd use the 18-70mm lens that came with it for most everything else. That is one reason I like the Sony. I know that that kit lens isn't as good as what comes with the Canon but the larger focal length is great. It also means I wouldn't immediatly have to get a longer lens. Outside of that I'd eventually get wide angle lens. But In the beginning I think the kit lens and a 70-300mm would cover just about everything I'd need. If I need close up macro shoting I'll still have my point and shoot which does a good job with that. Also it appears that anything with a maximum aperture in the 2.8-1.2 range will be out of my budget ( I hate not being rich:x)

But for a 70-300mm lens, does that sigma I orginally posted appear to be a good lens? All the stuff on the Sigma website confuses me. I obviously don't know much about all the technical phrases when it comes to lenses and photography in general. Which is why I'm takeing a photography class next year. But slowly I will learn

 

[Overread]

The sigma is as good as you will get for the price
I have used it and whilst its not stella, it does offer a lot and its a very popular lens with those new to the game as it does offer a lot of features - macro and 70-300mm zoom would usually be 2 different lenses or a zoom with some extension tubes.
If you are to get the 70-300mm go for the APO edition - it is an improvement over the original and the price difference is not too great - there are a few users of that sigma on the site and many can get good results with it

 

[prodigy2k7]

Almost any lens under $300 isnt a good quality lens... That is a very vague and easilbreakable rule. But if you ask a question like "Is BrandA 18-200mm F/4-5.6 for $100 a good lens" Probably not...