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10-18-2011, 07:48 AM   #1
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Choosing a Lens

Choosing a new lens (or used lens for that matter) seems to be one of the most difficult things for people on the forum. I guess I thought that I would share my mind set with regard to choosing what lens to purchase and hopefully others can give input too.

First of all, I think the most important feature of a lens is focal length. There is no turning a 200 mm lens into a 8-16mm zoom. Deciding on what focal length I need/want really narrows down the decision process. I don't think I can emphasize enough that the focal length is the crucial feature of a lens and figuring out what you want/need in this respect is the biggest factor in my decision.

Second, I think comes budget. This really comes near the top for me. Even if there are great lenses out there for 2000 dollars, they aren't going to be for me. At the same time, it is important to pay for quality. It is better to save for a lens that I will really use and enjoy than to buy a cheaper option now, that I will want to sell in six months because its lack of quality frustrates me.

Third comes everything else. By now, I have usually narrowed my search down to two or three lenses and I can focus on individual features. Wider aperture, size, build, and bokeh are all important features that can push me one way or another.

Finally, I think it is important not to buy lenses based on the lens club photos. Just because someone else can get the DA 15mm to work well for them, doesn't mean that I will be able to do the same and in fact, I don't really like to shoot that wide. There is always a "hot" lens that everyone else is making awesome photos with, but that lens often isn't what I want or need.

By following this decision making process, I have been able to avoid LBA and actually collect a set of lenses that I both use and enjoy.

10-18-2011, 08:23 AM   #2
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Good thoughts, but avoid LBA? Well, now that's just not right. We are here to serve LBA not to avoid it!
10-18-2011, 08:34 AM   #3
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QuoteOriginally posted by blackcloudbrew Quote
Good thoughts, but avoid LBA? Well, now that's just not right. We are here to serve LBA not to avoid it!
haha, agreed
10-18-2011, 10:01 AM   #4
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A really practical approach: start with the kit lens or two lens set. Take a lot of photos. When you want another lens, use those photos as a set of data. Figure out what focal length you need by looking at focal lengths you commonly use, or how much you need to crop a photo to get the image you want, or how much more field of view you want to add to a photo. The exposure information, especially for low light photos, can be used to calculate what you'd get from a faster lens. Say you have a photo with the 18-55 at 50mm, f5.6, 1/60 sec., ISO 1600, and you're looking at a Pentax-F 50mm f1.7. With that lens, you could shoot at ISO 200, f2.0 and 1/90 sec. Once you have a better idea of focal length and speed, you can look at lenses within those parameters and check prices. Sometimes there are only a handful of choices, and sometimes still too many, so you'll have to filter further based on features, image quality, etc.

There was a Dilbert cartoon a few weeks ago, the CEO complaining about the plummeting value of his carefully selected portfolio of stocks, the pointy-haired boss replying that he bought gold because it was shiny and he was up 100%. I do the shiny thing for lenses.

10-18-2011, 10:55 AM   #5
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QuoteOriginally posted by blackcloudbrew Quote
Good thoughts, but avoid LBA? Well, now that's just not right. We are here to serve LBA not to avoid it!
LBA isn't all bad, as long as you have your basic lenses already covered. I'm just afraid that there are newer photographers out there who need a particular lens who are blowing their budgets getting lenses that, while nice, don't really fit a need that they have.
10-18-2011, 11:16 AM   #6
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Ron and Dave, you both have good approaches. I've mentioned mine in other threads: 1) coverage, 2) speed, 3) character -- and 4) mania! Lens choices usually aren't made in a vacuum. Many of us moved to dSLRs from P&S's, even those with superzooms, and so we *should* have some idea how wide and long a focal range we desire, and of focal-length FOV equivalences. That's what helped drive me to an original kit of DA10-17, DA18-250, and FA50/1.4, from a 7-28mm P&S that's FF-'equivalent' to 34-136/2.8-4 (or 23-91mm on APS-C). I knew I wanted wider and longer and faster.

So we (hopefully) think about what we want to do that can't be done with the P&S, that we don't just jump naked into the dSLR lava flow. But what do we do if we ain't rich? Kit.lenses.

I've mentioned more than once that I quite dislike 2-lens kits, with the 18-55 plus 50-200 or 55-300, because I hate swapping lenses right in the middle of my most-used 35-70mm range. But I admit that such a 2-lens kit *is* a good cost-effective way to jump into dSLRs. Then we can note which focal lengths we like, which FLs we should think about getting faster 'better' lenses.

The kit.lenses are good training wheels. Some never desire anything else. That's fine. Some find that a very limited kit all that's needed, maybe just 18-70 and 70-200 f/2.8 zooms. That's fine. And then if budget allows, go for some good Limiteds and/or speed demons. Groovy! And some of us keep accumulating cheap old glass, not for LBA, but just to see how different optics work. I like having a large toolbox of lenses. It saves me from boredom.
10-18-2011, 11:08 PM   #7
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Good points made by all. Download a program such as Exposure Plot and run it against several months' exposures. I find this easiest if I make really small jpegs out of Lightroom into a directory (How about long side = 8 px) temporarily. The EXIF is there, but you have all your exposures in one place. Run the plot, then see where you are usually shooting. If you have the kit 18-55, and half your exposures are at 18 and only 1/10 at 55, you should examine wider before longer. or vice versa. When I bought my K10, for example, I bought a kit with the 12-24 because with film, I was at the point that 24mm (16 digital) was just not wide enough for me any more.
10-18-2011, 11:38 PM   #8
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QuoteOriginally posted by Rondec Quote
First of all, I think the most important feature of a lens is focal length. There is no turning a 200 mm lens into a 8-16mm zoom. Deciding on what focal length I need/want really narrows down the decision process. I don't think I can emphasize enough that the focal length is the crucial feature of a lens and figuring out what you want/need in this respect is the biggest factor in my decision.
What I really need is another dozen 50s or so!

QuoteOriginally posted by Rondec Quote
Second, I think comes budget. This really comes near the top for me. Even if there are great lenses out there for 2000 dollars, they aren't going to be for me. At the same time, it is important to pay for quality. It is better to save for a lens that I will really use and enjoy than to buy a cheaper option now, that I will want to sell in six months because its lack of quality frustrates me.
But I want the 31 Ltd. I wants it, I wants it I wantsss it!

QuoteOriginally posted by Rondec Quote
Finally, I think it is important not to buy lenses based on the lens club photos. Just because someone else can get the DA 15mm to work well for them, doesn't mean that I will be able to do the same and in fact, I don't really like to shoot that wide. There is always a "hot" lens that everyone else is making awesome photos with, but that lens often isn't what I want or need.
That's a very sad and profound truth!

On a more serious note: You made some good points, and I usually try to use rather similar criteria when buying lenses, but when I found that A 50 F1.2 or the 8-element Takumar 50 F 1.4 on the bay for example, I just couldn't help myself...

10-19-2011, 03:43 AM   #9
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QuoteOriginally posted by RioRico Quote
Ron and Dave, you both have good approaches. I've mentioned mine in other threads: 1) coverage, 2) speed, 3) character -- and 4) mania! Lens choices usually aren't made in a vacuum. Many of us moved to dSLRs from P&S's, even those with superzooms, and so we *should* have some idea how wide and long a focal range we desire, and of focal-length FOV equivalences. That's what helped drive me to an original kit of DA10-17, DA18-250, and FA50/1.4, from a 7-28mm P&S that's FF-'equivalent' to 34-136/2.8-4 (or 23-91mm on APS-C). I knew I wanted wider and longer and faster.

So we (hopefully) think about what we want to do that can't be done with the P&S, that we don't just jump naked into the dSLR lava flow. But what do we do if we ain't rich? Kit.lenses.

I've mentioned more than once that I quite dislike 2-lens kits, with the 18-55 plus 50-200 or 55-300, because I hate swapping lenses right in the middle of my most-used 35-70mm range. But I admit that such a 2-lens kit *is* a good cost-effective way to jump into dSLRs. Then we can note which focal lengths we like, which FLs we should think about getting faster 'better' lenses.

The kit.lenses are good training wheels. Some never desire anything else. That's fine. Some find that a very limited kit all that's needed, maybe just 18-70 and 70-200 f/2.8 zooms. That's fine. And then if budget allows, go for some good Limiteds and/or speed demons. Groovy! And some of us keep accumulating cheap old glass, not for LBA, but just to see how different optics work. I like having a large toolbox of lenses. It saves me from boredom.
You have to start somewhere and kit lenses are the cheapest way to begin. The question is where you go when you begin to get new lenses.. I just see a lot of confused posts asking questions like "Should I get the FA 31 or the DA 70?" That sort of decision should be easy. The harder decision is between the DA 70 and the FA 77 or the Sigma 70mm.

I have ruled out purchasing most of the FA limiteds purely because of focal length. The 77 is too long for me and the FA 43 is either too long or too wide, depending on the situation. I do best with a 30 mm and a 55mm on APS-C. That is not true for everyone, but its true for me. Knowing that helps me to fine tune my gear considerably, particularly when it comes to travel.
10-19-2011, 04:00 AM   #10
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chosing a lens should be really easy, actually.
it should be 100% mission driven.

if you think about what you want to do the parameters for the lens should be clear. Then check your budget, and BANG, you got a decision.
10-19-2011, 08:22 AM   #11
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QuoteOriginally posted by kanzlr Quote
if you think about what you want to do the parameters for the lens should be clear. Then check your budget, and BANG, you got a decision.
Except for that lousy thing known as "money" is in very restricted supply in this house. Other than that, I would be shooting with a 400/2.8 instead of my 400/5.6 and would have a big solid tripod - well bigger than my Manfrotto 055, anyway. I'd need it for the 2.8. Them is real heavy. I have a friend in Montana who uses pack llamas, so the backpack would do for lunch. Now about that FA* 600/4 ...
10-19-2011, 08:53 AM   #12
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I'm very practical and pragmatic about lenses, and after decades of zooms, I switched to all primes. There are a lot of reasons for this, but the most important is the first one the OP mentioned: focal length. Having all primes, I can look at a scene and can automatically see what FL is best, because I have only five, and I'm familiar with the POV of all. This give me a "photographic vision." Besides, with primes, I'm better at comp.: which means they make me a better photographer. I have yet to come across a scene I couldn't capture with either my 15mm, 35mm, 50mm, 100mm or 200mm. With few lenses and all primes, I've learned the sweet spots and ultimate assets of each. IQ is a big deal to me, and I think saving to get a good lens is far better than filling a shelf with sub-par glass.
It also took me decades to really lean the importance of glass, which is why I often say: The body gets you there, but it is the eye (lens) that sees.
10-19-2011, 11:59 AM   #13
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QuoteOriginally posted by Just1MoreDave Quote
A really practical approach: start with the kit lens or two lens set. Take a lot of photos. When you want another lens, use those photos as a set of data. Figure out what focal length you need by looking at focal lengths you commonly use, or how much you need to crop a photo to get the image you want, or how much more field of view you want to add to a photo.
There are two problems with this approach. First, what focal length one prefers may be dependent on aperture. It's possible, for example, that someone prefers to 28mm over 55mm when they shoot at f5.6, but would prefer 55mm to any focal length if they could shoot at f1.4. Yet if all they have ever used is the kits lens, they won't be in a position to know this. If they want a fast lens, it will be for shooting hand-held in lowlight, not for narrow DOF, which they won't be in a position to fully appreciate.

The other problem arises from the fact that it may not be a good thing, from the perspective of developing one's photographic talent, for a person to be continually using the focal ranges they are most comfortable at. Perhaps the comfort level reflects bad compositional habits reinforced by the versatility and "practicality" of the zoom. Perhaps the comfort level merely reinforces skill at using one specific focal length(s), at the expense of skill using others. If you want to be really good at something, sometimes you have to concentrate more on where you weakest. In basketball, for instance, you may have to practice more with your off-hand, because that's where you're weakest. Perhaps being forced to use focal lengths one is not completely comfortable with is better for the development of one's skill and talent, and will, in the long run, make one into a more well-rounded photographer.

In any case, it was not so very long ago when every photographer started out using primes. In terms of learning photography, there are real advantages to using primes, as they are better at teaching the benefits of narrow DOF and because, precisely due to their limitations, they force one to really think about composition, rather than settling for the easy, cliche shot.
10-19-2011, 02:36 PM   #14
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That's another approach: no zooms, primes only, preferably manual.

1-lens kit: get a 28mm.
2-lens kit: add a Fast Fifty.
3-lens kit: add an old 135/2.8.
4-lens kit: add a Zenitar 16/2.8.
5-lens kit: add a Tele-Takumar 200/5.6.
And throw in a Raynox and/or macro tubes.

RANT: Many of these what-lens-to-get lists assume that a pared-down lens kit is best. Also that once a lens is bought, it must be kept. Also that new & advanced are best. I disagree. I have a zillion lenses, mostly cheap old manual primes, and it's very rewarding to see what each can do. Any lens must be satisfying; if not, return or resell it. And many old cheap lenses have great performance WITHIN THEIR LIMITATIONS of focus and aperture.

What-to-get depends on what-is-expected. If snapshots are expected, go with kit lenses. If fine art is expected, get certain classic glass. If random fun is expected, get lots of cheap old stuff. If professional quality is expected, get professional tools. If danger is expected, get disposable gear. Just don't feel limited to only the fewest newest best lenses -- that's the route to neurotic ulcers and poverty. My Limiteds are better than yours! Yeah, right...
10-19-2011, 03:44 PM   #15
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Yes, choosing lens is not easy, especially as your prefered FL will shift over time. I used to have my DA40 glued to my camera, then I got the DA15 and it changed my entire way of looking at it. Check out this gallery wich contains photos of Vancouver all with the DA15: Zenfolio | Roger St-Pierre Photography | Vancouver, BC

No matter what you decide, it's never going to be the end... ;-), just try not to have too many duplications of Focal Ranges.
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