Lens Nomenclature + Zoom Lens

[tootboink]

hello all!

i got my k-x a month ago.. and all these while i've been happily using my kit lens, intending to max out its and my potential before investing in another one, and in the meantime find out which lens i need/want.

a few recent events have left me wishing for primarily a lens with more zoom. For example, i went for my brother's commisioning parade on saturday, and was really limited with my kit lens. Now, while i have uncovered what type of lens i want, the downside is that as a newbie i devoted much more time to shooting, and i had never bothered a single bit about lens - their nomenclature, reputations, etc etc - up to now.

hence i have a few questions!

1. what does a name of a Pentax lens consist of and what can we know about it? The only thing i know for sure is the focal length, of course. What about DA, DAL, DA* etc etc? As well as the other initials that may appear in the lens name? I believe also that F4-5.8 for example refers to the aperture range. However that does not appear all the time when i see fellow csers talking about lenses. Is that part of the name of a lens also?

2. third party lens! tamron and sigma are the brands i read of the most. Needless to say, apart from the focal length, i know nothing else about it whenever i read of fellow csers discussing them. does any brand have a specialty?

3. what are the reputations of the various brands of zoom lens? are there any popular ones? also, can i deduce that what i am refering to are also named "telephoto" lens?

4. will the picture quality of a 18-200 lens be poorer that that of a 18-55 or a 50-200 lens? in other words, is there a price(apart from the literal price:bsmilie to pay for convenience?

5. what are primes? i have heard of lens with fixed focal lengths or fixed apertures. are those called primes? i vaguely recall primes being linked with delivering specially good bokeh. correct me if i am wrong please.

6. lastly, maybe a recommendation of a zoom lens for me as well as the price range i can expect? i do know i can check out price guides.. but that will have to wait until i understand the lens nomenclature and arrive at a decision. meanwhile, could i get help in knowing roughly what to expect?

thanks in advance for answering my questions, or perhaps pointing me in a direction where i can get my answers. i do understand the pain of watching a newbie ask questions of answers they can so easily get themselves.

 

[sebianos]

Okay, I'm answering this because other seniors have been very kind to me. And i can't bear to see them go... "not again, another newbie who never do his own research."

1. what does a name of a Pentax lens consist of and what can we know about it?


For eg. "Pentax SMC DA 1:3.5-5.6 18-55 AL II" - Brand is Pentax, SMC refers to Super-multi-coated, DA is the range of lenses, 3.5 - 5.6 refers to the maximum aperture, 18-55 refers to the zoom range (this is actually more complicated because of the crop factor and everything should be baselined to 35mm equivalent so that there's a basis of comparison). AL refers to Aspherical Lenses. II means version 2. You have to look at various lenses to find out what they means.

What about DA, DAL, DA* etc etc?

DA, DAL, DA*, M, K, FA, FA J, DFA, WR, Limited refers to the range the lenses belong to. DA - For DSLR, DAL - For DSLR but L denotes kit lens range, DA* is top of the range for DSLR lenses, M = Manual Focus for film slr but can be adapted for dslr, K = the other range of Manual Focus, A = comes with aperture control, FA = autofocus lenses for film slr, FA j = budget focus of autofocus lenses, DFA = lens suitable for DSLR & SLR, WR = Weather Resist.

Apart from range, lenses are classified into Macro, Ultra Wide Angle, Wide Angle, Normal Primes, Telephoto in Short, Medium, and Long Ranges. From ultra wide, 10-28mm, 28-58, 85-135,150-200,300-1000 are rough gauge of the classifications.

2. third party lens! tamron and sigma are the brands i read of the most. does any brand have a specialty?

Every single lens has it's specialty but some stand out more. The joy is looking for one that's suitable and pleases you. Don't know much about tamron or sigma.

3. what are the reputations of the various brands of zoom lens? are there any popular ones? also, can i deduce that what i am refering to are also named "telephoto" lens?


OK, i make the same mistake - zoom refers to variable focus lenses. Like the Kit lens is zoom. Telephoto refers to a classification of lenses where the focal length is very long. 135mm and above.

4. will the picture quality of a 18-200 lens be poorer that that of a 18-55 or a 50-200 lens? in other words, is there a price(apart from the literal price) to pay for convenience?

You need a course in Optical Science for that. hahahaha... There are always tradeoffs for convenience. The perfect lens will cost a bomb and weigh 3 kgs if you're seeking perfection. What's important is if the lens you have now suits your needs and current level of Image Quality. ;p

Picture quality will change if you change your apertures. The smaller the aperture goes, the sharper the image. Aperture size is inverse to the F number - so the higher the f number, the smaller the aperture. Remember that.

5. what are primes? i have heard of lens with fixed focal lengths or fixed apertures. are those called primes? i vaguely recall primes being linked with delivering specially good bokeh. correct me if i am wrong please.

Primes are fixed focal length lenses in general. I won't touch a fixed aperture lens if they ever made one. Oh well, maybe the Vivitar Ultra Wide and Slim. Any decent lenses can have bokeh, only diff is the quality of the bokeh delivered. That's highly subjective.

6. lastly, maybe a recommendation of a zoom lens for me as well as the price range i can expect? i do know i can check out price guides.. but that will have to wait until i understand the lens nomenclature and arrive at a decision. meanwhile, could i get help in knowing roughly what to expect?


OK, now you know the nomenclatures. Go find your zoom lens. Opinions will vary a lot and as I'm not interested in zooms at the moment. You can ask the others to let you test the lenses in the next outing.

or perhaps pointing me in a direction where i can get my answers.
The usual suspects,
http://www.pentaxforums.com/lensreviews/index.php
Google for any Pentax lens brochure or go look at photo.net learn. All of them have good articles on building a lens arsenal.

i do understand the pain of watching a newbie ask questions of answers they can so easily get themselves.

OK, the next newbie who ask these questions. You have to promise to answer all of them. Or at least dig out this post and show them.

Hahahahahaha... ok, guess I balanced off the karma with this long one.

PS. I won't overload you with M42 lenses but they refer to screwmount as opposed to K mount (bayonet) lenses. Nor russian, german, or france lenses. They are really good. Some of them, at least. For Pentax M42 - Super Takumars are great.

 

[creampuff]

This would be a useful place to start. While it is a Tamron site with specific examples relating to their models, the information is pertinent to any brand.

http://www.tamron.com/lenses/learning_center/tools/focal-length-comparison.php

http://www.tamron.com/lenses/learning_center/pro_learning_center_choosing.asp

 

[elavan]

:thumbsup: for the hard work, deserves a sticky :bsmilie:

generally, for maximal IQ use Pentax lenses, for the budget conscious yet big on specs use 3rd party, sometimes you just need the speed at a fraction of the price, the IQ will suffer a little, but getting the shot is worth the trade-off. the core specs offered by them are very competitive for the price.

to attain the low price for 3rd party lens, some things are being traded off to keep price low, like build quality, no WR, lousy resistance to dust, coating quality, weaker flare/CA/PF resistance, and on the longer lenses, lacking some focus accuracy/speed. you will also read of horrible QC affecting above-mentioned parameters from 3rd party manufacturers sometimes.

but because my wallet not fat enough, so I use Sigma and Tamron.

specialties? nothing special, just attractive pricing..

 

[woefulwabbit]

Just to clarify, FA J is an FA lens without the aperture control ring.
There are fixed aperture lens.. usually the mirror lenses.

Yeah, you should avoid using the word "zoom" anymore. Zoom is just the action of changing focal lengths, while most newbies confuse "zoom" with telephoto, which is long focal length. The Sigma 10-20m is considered a zoom lens, even though its entire range covers ultra wide-angle.

I wouldn't look down on Sigma and Tamron. Afterall, they have lots of experience making lenses, and they make a lot of lenses for a wide variety of mounts. Look at each lens for its own merits, rather than the brand.

There will always be trade offs for convenience when going for a lens with large zoom range. They will usually suffer from more barrel distortion at the wideangle end, chromatic aberration and possibly pincushion effect at the telephoto end.

 

[creampuff]

Important to know every brand and every lens maker have their hits and misses in their lens line-up, Pentax included. There is nothing wrong with using 3rd party made lenses, in fact one of my favs is the older manual focus Sigma 50mm f/2.8 Macro. Third party lenses usually offer very good value and may make a focal length or zoom range that the OEM lens maker does not offer. A good rule of thumb where possible is to test before buying. All lenses are hand assembled in batches and there will always be ever so slight differences between copies.

Of course if you can get a lens with Pentax grand master fengwei's seal of approval even better. :bsmilie:

 

[pinholecam]

Just to clarify, FA J is an FA lens without the aperture control ring.
There are fixed aperture lens.. usually the mirror lenses.

FA J is short form for 'FA junk'

 

[tootboink]

thanks sebianos for the wonderful reply =D and other seniors for your tips. :bsmilie:

does it FA mean that i cannot use them for DSLRs?

yes.. the common misconception is that a zoom lens is a lens that allows you to zoom into a subject by a lot. that is not true. a zoom lens is simply a lens that allows you to adjust the focal length, be it small or great!

so let me refine my question.. i am looking for a telephoto lens ;p

looked through the price guides.. and the one that caught my eye wasthe DA18-250mm f/3.5-6.3 ED AL (IF). But it is discontinued!

Is it the only 1st-party all-in-one zoom lens? Based on the focal lengths, it seems to be the one i am looking for.

I see an alternative - the tamron AF 18-250mm f/3.5-6.3 Di II LD Aspherical (IF).

Do you know whether i can still buy the DA18-250? And do i have another alternative apart from the tamron 18-250? I do have an inclination to stick to 1st-party lens at the moment..

added - i saw bro sebianos mention "cheapy 50/f2 primes" as well as "50/1.4 or 50/1.7" in other threads, and praising them. It may be obvious, but can i confirm that it means that the prime lens have a fixed focal length of 50 mm and a maximum aperture of f/2, f/1.4 or f/1.7 respectively?

 

[sebianos]

You're welcome...

does it FA mean that i cannot use them for DSLRs?

All Pentax lenses, including FA and M42 mounts may be used on DSLRs (M42 with the appropriate adapters). What you have to know is... okay, secret tip. Some crappy primes/zooms that nobody will touch in the film slr era (because of vignetting, and blurred corners) are quite useable because of the crop factor. That is, they take the best part of the image minus the vignetter and soft corners. This means that crappy old lenses may yield good if not great IQ. That's good for DSLRs users.

Whereas DA lenses and anything with starting with DA are specifically tuned for DSLRs. Would probably look weird and YUCKS on a film SLR.

looked through the price guides.. and the one that caught my eye wasthe DA18-250mm f/3.5-6.3 ED AL (IF). But it is discontinued!

Well, if you're nice and ask politely in the Personal Classifieds. Quite sure somebody will offer you that lenses for a price. Oh if you're wondering what's ED AL (IF) - AL is Aspherical Lens, IF is Inner Focusing - which basically means only 1 element is moved to focus the image, ED is exceptionally high quality glass, like the Limited lenses.

Is it the only 1st-party all-in-one zoom lens? Based on the focal lengths, it seems to be the one i am looking for.

Seems like it. Go third party then... some 3rd party like vivitar uses other companies to make their lenses. Some are even better than Pentax ones. Since, I'm not expert in zooms or third party lenses - can ask the helpful experts here. :embrass:

I do have an inclination to stick to 1st-party lens at the moment..

Urm... word of advice. Open up the horizons - there are many good makers out there. Carl Zeiss for one, Ricoh (maybe), Yashica, and Russians like TAIR, Helios... all yummilicious.

added - i saw bro sebianos mention "cheapy 50/f2 primes" as well as "50/1.4 or 50/1.7" in other threads, and praising them. It may be obvious, but can i confirm that it means that the prime lens have a fixed focal length of 50 mm and a maximum aperture of f/2, f/1.4 or f/1.7 respectively?

Yep, 50/1.4, 50/1.7, 50/4 Macro (heh heh :lovegrin. The first refers to focal length, and 2nd is the aperture. Usually f1.4 all the way to f22, some goes all the way up to f32. Hmmm... now you're speaking like a lens expert too. :thumbsup:

And yes, I do love all my primes. Once you get over the manual focusing but I'm not in a hurry to shoot and my subjects are mostly static for now.

This is shot with a M135/3.5 prime lens. See how the flower pops with minimal contrast/brightness adjustment and zero sharpening. :bsmilie:

 

[sebianos]

:thumbsup: for the hard work, deserves a sticky :bsmilie:

....

but because my wallet not fat enough, so I use Sigma and Tamron.

specialties? nothing special, just attractive pricing..

Elavan, will definitely ask you when it comes to Sigma and Tamron. Attractive pricing always sounds good to me :bsmilie:

 

[woefulwabbit]

Well, when you say telephoto lens I think more of things like the 55-300mm or 70-200mm or a 200mm or 300mm prime.
18-250mm is more of a megazoom lens since it covers both wide angle and long telephoto.
But ya, you can still find Pentax and Tamron 18-250mm around, you need to call up the shops to check though. Can start with MS Color and Orient Photo

 

[creampuff]

does it FA mean that i cannot use them for DSLRs?

You can use FA series lenses with no problems on Pentax DSLRs.
In fact some prefer the FA lenses over the newer DA lenses.

... and the one that caught my eye was the DA 18-250mm f/3.5-6.3 ED AL (IF). But it is discontinued!

I see an alternative - the tamron AF 18-250mm f/3.5-6.3 Di II LD Aspherical (IF).

Do you know whether i can still buy the DA18-250? And do i have another alternative apart from the tamron 18-250? I do have an inclination to stick to 1st-party lens at the moment..

The Pentax and Tamron are similar. You can still find them on sale, (if not in the shops, then online) but be mindful that there are many trade-offs for that wide zoom range.

added - i saw bro sebianos mention "cheapy 50/f2 primes" as well as "50/1.4 or 50/1.7" in other threads, and praising them. It may be obvious, but can i confirm that it means that the prime lens have a fixed focal length of 50 mm and a maximum aperture of f/2, f/1.4 or f/1.7 respectively?

A prime lens is just a lens with a fixed focal length, that's all. The maximum aperture can vary according to the lens design.

 

[creampuff]

...What you have to know is... okay, secret tip. Some crappy primes/zooms that nobody will touch in the film slr era (because of vignetting, and blurred corners) are quite useable because of the crop factor. That is, they take the best part of the image minus the vignetter and soft corners. This means that crappy old lenses may yield good if not great IQ. That's good for DSLRs users.

Well from my limited experience, a crappy lens is still crap even if only the center portion of the image is used on current APS-C DSLRs. The center sharpness might be a touch better than the edges but a junk lens will show up it's shortcomings pretty fast, especially with the higher resolution of current digital camera sensors.

I once went through a phase looking out for such "budget wonders" but after using them, that familiar phrase "just cannot make it" always comes to mind. Frankly better to save up and get a good modern lens right from the start than trying out the old clunkers that nobody wants. You will be dissatisfied pretty quick and will want to upgrade for better quality glass and you'll soon realize you have actually wasted money in the process... :cry:

 

[tootboink]

You can use FA series lenses with no problems on Pentax DSLRs.
In fact some prefer the FA lenses over the newer DA lenses.



The Pentax and Tamron are similar. You can still find them on sale, (if not in the shops, then online) but be mindful that there are many trade-offs for that wide zoom range.



A prime lens is just a lens with a fixed focal length, that's all. The maximum aperture can vary according to the lens design.

may i know what are some of the tradeoffs for having such a wide zoom range?

 

[woefulwabbit]

may i know what are some of the tradeoffs for having such a wide zoom range?

Barrel distortion, chromatic aberration, pincushion effects
The lens can be designed to minimize the above effects for a particular focal length, but these effects will be increased the further away you are from the 'optimum' focal length.

 

[gibss]

I used to stay away from the 3rd party lenses, but once I got to know them, it really broadened my knowledge base (and also made me more tempted to buy lenses XD).

Tamron, Sigma and Tokina are the big three, they usually like to create lenses that either C&N don't cover, or create a new lens range altogether.

eg.
Tamron 17-50 f2.8 ($600) is a MUCH cheaper alternative to Nikon's 17-55 f2.8 (~$1.6k)
Sigma 50-500 (aka Bigma) is a marvel by itself (10x zoom XD)
Tokina's 11-16 f2.8 is the fastest wideangle zoom lens.
and the list goes on...

Having said that, please do consider carefully what lens you need (and not want) and what objectives you want to accomplish with the lens.

Happy exploring!
gibss.