Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
12-14-2010, 07:06 PM   #1
New Member




Join Date: Dec 2010
Location: north carolina
Posts: 9
Pentax A lenses on k-x

I just purchased a new K-x, am rather new to photography so I'm just beginning to learn how complex choosing a lens can be for the inexperienced. I would like opinions as to which of the older Pentax "A" lenses give a good result for indoor, group pictures. I'm thinking one of the prime lenses but I'm open to the voice of experience.

12-14-2010, 07:11 PM   #2
Veteran Member
Docrwm's Avatar

Join Date: Sep 2010
Location: Somewhere in the Southern US
Photos: Gallery | Albums
Posts: 11,275
QuoteOriginally posted by ldmlkn Quote
I just purchased a new K-x, am rather new to photography so I'm just beginning to learn how complex choosing a lens can be for the inexperienced. I would like opinions as to which of the older Pentax "A" lenses give a good result for indoor, group pictures. I'm thinking one of the prime lenses but I'm open to the voice of experience.
Welcome aboard. I bought my K-x in September and am really enjoying learning a lot here. Well, you have three criteria I think in what you are asking for:
1 - good in lower light (indoor)
2 - wider angle (group and indoors)
3 - Pentax A lens

For wider angle on the older lenses you will want something like a 28mm and the f2.8 is fairly common. You can see the reviews of it here - SMC Pentax-A 28mm F2.8 Lens Reviews - Pentax Lens Reviews & Pentax Lens Database

Not terrible on price, wide enough and fast enough for a lot of what you're asking about, and generally positive reviews.
12-14-2010, 07:21 PM   #3
Veteran Member




Join Date: Apr 2009
Location: Dallas, TX
Photos: Gallery | Albums
Posts: 499
Depending on your conditions (how bright is the light, etc) you may want to increase the lens to a 50mm 1.4-1.7 if you can. While it's not a huge step, if shooting conditions are dark you'll need every bit you can get. I'm not extremely familiar with the Kx (I'm a K-10 guy), but if you can compensate by increasing your ISO, then my point may be moot.

However, if you are shooting fast moving targets (kids, pets, etc) then I'd go for something a bit longer to get the best aperture possible.
12-14-2010, 07:25 PM   #4
New Member




Join Date: Dec 2010
Location: north carolina
Posts: 9
Original Poster
Thanks for the rapid response! That was one of the lenses(28mm f2.8) I had in mind as I try to get up to speed for Christmas. A quite affordable one as well. Thanks, Lannie

12-14-2010, 09:24 PM   #5
Veteran Member




Join Date: Oct 2010
Location: Taiwan
Photos: Gallery | Albums
Posts: 1,073
I'm not sure if the A28/2.8 is going to give you much of an improvement over the kit lens (I'm assuming that you have this) as far as speed. It's only a 1 stop improvement which is an improvement but you might be looking for more. imo the 28/2.8 is nice for its compact size and it takes great photos. But it might not do what you are hoping.

Unfortunately the faster 50mm lenses are not that great group photos indoors.
12-15-2010, 05:47 AM   #6
Veteran Member
Docrwm's Avatar

Join Date: Sep 2010
Location: Somewhere in the Southern US
Photos: Gallery | Albums
Posts: 11,275
QuoteOriginally posted by abacus07 Quote
I'm not sure if the A28/2.8 is going to give you much of an improvement over the kit lens (I'm assuming that you have this) as far as speed. It's only a 1 stop improvement which is an improvement but you might be looking for more. imo the 28/2.8 is nice for its compact size and it takes great photos. But it might not do what you are hoping.

Unfortunately the faster 50mm lenses are not that great group photos indoors.

I agree that its a compromise between angle of view and speed. The rarer SMC Pentax-A 28mm F2 or the SMC Pentax-A 35mm F2 might serve better with both wider view and faster aperture. But they are harder to find and typically cost 4-6x as much as the 28/2.8.
12-15-2010, 06:09 AM   #7
Veteran Member




Join Date: Oct 2010
Location: Taiwan
Photos: Gallery | Albums
Posts: 1,073
QuoteOriginally posted by Docrwm Quote
I agree that its a compromise between angle of view and speed. The rarer SMC-Pentax-A-28mm-F2 or the SMC-Pentax-A-35mm-F2 might serve better with both wider view and faster aperture. But they are harder to find and typically cost 4-6x as much as the 28/2.8.
No disagreement but I'm just pointing out that the A28/2.8 isn't really the solution to the problem that he presented. I like the 28/2.8 but 1 stop faster might not make any difference if he's having problems.
12-15-2010, 06:25 AM   #8
Veteran Member
Docrwm's Avatar

Join Date: Sep 2010
Location: Somewhere in the Southern US
Photos: Gallery | Albums
Posts: 11,275
QuoteOriginally posted by abacus07 Quote
No disagreement but I'm just pointing out that the A28/2.8 isn't really the solution to the problem that he presented. I like the 28/2.8 but 1 stop faster might not make any difference if he's having problems.
Just trying to meet his parameters. A Fast Fifty would be nice but it will not do groups in a normal sized home. There aren't any Pentax lenses that are "A"s <f2 other than the 50s and two * models (85 & 135) which are typically even harder to find, are more expensive, and are even less useful for group shots inside a typical home than the 50s.

Getting the lowest practical f stop (in this case the 28/2.8 IMHO) + learning to use Higher ISO settings (and maybe a flash) are the practical solutions to shooting a group inside the house IMHO.

12-15-2010, 07:26 AM   #9
Veteran Member




Join Date: Oct 2010
Location: Taiwan
Photos: Gallery | Albums
Posts: 1,073
I guess I would be hesitant suggesting something that is going to show a minimal improvement (if he has the kit lens) of his parameters. I would hate to see him asking the same question in 2 months because this didn't work. It will be an improvement and as long as he understands that the improvement might only be minimal then it's a good suggestion.

The best case would be for him to post example photos (with EXIF) and see exactly how much of an improvement is needed. I'm comfortable with telling someone that that they might not be able to take the photo they want without a substantial investment. While others prefer to buy lenses and see if it works. This reminds me of the beginner that wanted to take nighttime action sports. the first suggestions were which lenses to buy before they agreed that this might be an impossible task without spending a lot of money.
12-15-2010, 11:29 AM   #10
Pentaxian
Just1MoreDave's Avatar

Join Date: Feb 2007
Location: Aurora, CO
Photos: Gallery | Albums
Posts: 4,817
The first thing to do is set your kit lens to various focal lengths like 28, 35, 40 and 50, get some people together where your real photos will be, and see how it works. It may not be necessary to actually take the shots, but you should get a quick idea if everyone fits in the frame, where you'd have to stand, etc. With a focal length or range in mind, your search will be easier and you will be more likely to get the right lens for you. Maybe you live in the Biltmore and don't like your subjects, so a 300mm would be best for you.

I think the lens to keep in mind is the Pentax 35mm DA L f2.4, for around $220 at B&H, maybe cheaper if you search elsewhere. Even if you really want to try an older manual focus prime, the new lens gives you a price guide. The lens should work great, and it's easy to buy.

I also like the 28mm lenses suggested. The Pentax-A 28mm f2.8 is an excellent lens. I use the F version, optically the same but with autofocus, because I got it cheap. The A is maybe $100, the F is in the price area of the DA L 35/f2.4, a bit high for me. You may be able to find a Vivitar 28mm f2.8 with an A setting for cheaper than the Pentax. They are pretty good but I wouldn't pay more than the Pentax price for one. Faster than f2.8 gets expensive at 28mm. I have a Sigma manual-focus 28mm f1.8, I think they call it an Ultra High-Speed Wide II, with the A setting that is nice, but somewhat rare. That shows up for around $200.

I would not buy the Pentax 35mm lenses older than the FA 35mm f2. I've tried all of the optical formulas and the only sharp version is the 35mm f3.5, which then is too slow for me. Prices are also high. That new lens is hard to beat.
12-15-2010, 07:29 PM   #11
Loyal Site Supporter
birdman59's Avatar

Join Date: Mar 2010
Location: Marietta, Oh
Posts: 93
I bought a 50mm f2.0 Asahi lens from Ebay for $20 and really like using it for still lifes and portraits. Its a nice sharp lens. Just a few things to consider...

1. Manual focus can be difficult on a Kx. The focus screen is not user friendly.

2. in Av mode, the camera will shoot wide open (at f2.0 in my case) and adjust shutter speed accordingly. You will not have very much creative control.

3. In Manual mode, you can get meter readings with the green button and set f stops and ISO. It takes longer to compose a photo. That can be a good thing as it forces you to think about what you are doing all the time. This can be a good thing because this is where you will learn the most.
12-16-2010, 05:21 AM   #12
Veteran Member
Docrwm's Avatar

Join Date: Sep 2010
Location: Somewhere in the Southern US
Photos: Gallery | Albums
Posts: 11,275
QuoteOriginally posted by Just1MoreDave Quote
The first thing to do is set your kit lens to various focal lengths like 28, 35, 40 and 50, get some people together where your real photos will be, and see how it works. It may not be necessary to actually take the shots, but you should get a quick idea if everyone fits in the frame, where you'd have to stand, etc. With a focal length or range in mind, your search will be easier and you will be more likely to get the right lens for you. Maybe you live in the Biltmore and don't like your subjects, so a 300mm would be best for you.

I think the lens to keep in mind is the Pentax 35mm DA L f2.4, for around $220 at B&H, maybe cheaper if you search elsewhere. Even if you really want to try an older manual focus prime, the new lens gives you a price guide. The lens should work great, and it's easy to buy.

I also like the 28mm lenses suggested. The Pentax-A 28mm f2.8 is an excellent lens. I use the F version, optically the same but with autofocus, because I got it cheap. The A is maybe $100, the F is in the price area of the DA L 35/f2.4, a bit high for me. You may be able to find a Vivitar 28mm f2.8 with an A setting for cheaper than the Pentax. They are pretty good but I wouldn't pay more than the Pentax price for one. Faster than f2.8 gets expensive at 28mm. I have a Sigma manual-focus 28mm f1.8, I think they call it an Ultra High-Speed Wide II, with the A setting that is nice, but somewhat rare. That shows up for around $200.

I would not buy the Pentax 35mm lenses older than the FA 35mm f2. I've tried all of the optical formulas and the only sharp version is the 35mm f3.5, which then is too slow for me. Prices are also high. That new lens is hard to beat.
I think the DAL 35/2.4 is a good option but didn't recommend it as the OP had specified A lenses. I learn something new every time I read posts here, I did not realize that there was an F version of the 28 lens. I'll have to go read more about it - thanks.
12-16-2010, 06:45 AM   #13
Inactive Account




Join Date: Dec 2008
Location: Ames, Iowa, USA
Photos: Albums
Posts: 2,965
While I'm an advocate of A type lenses, I think your best strategy for now is to crank up your ISO and use the kit lens.

The K-X's high ISO image quality may well be good enough for your needs*; if not, you'll discover what ISO is acceptable then be able to determine how wide and fast a lens you need.

The play-off between ISO, f-stop, and exposure time is:

constant = ISO*time/(f-stop)_squared

That is, changing f-stop by a factor of 2 is equivalent to changing ISO by a factor of 4 for the same exposure time. Or, decreasing one full f-stop (like 3.5->2.8) allows cutting exposure time in half for the same ISO.

The best strategy for deciding what you need is to first find the maximum ISO acceptable for your images*; then you'll be able to determine how fast a lens you need. Take a bunch of low-light photos at differing ISOs, (maybe using a tripod) to find out what's acceptable; only then can you accurately decide on minimal lens requirements.

Keep in mind that wide, fast, A type lenses are rare indeed! The ~$150 Sigma 24:2.8 is pretty good wide open and the ~$650 Pentax FA* 24:2 is about the fastest you'll get. OOPS just saw that Sigma has a 24:1.8 ($450) for Pentax mount.

Dave

* the maximum ISO acceptable for a computer screen display or a 4x6" print is usually greater than that for an 8x10" print.

Last edited by newarts; 12-16-2010 at 05:46 PM.
12-16-2010, 01:40 PM   #14
Pentaxian
Just1MoreDave's Avatar

Join Date: Feb 2007
Location: Aurora, CO
Photos: Gallery | Albums
Posts: 4,817
QuoteOriginally posted by Docrwm Quote
I think the DAL 35/2.4 is a good option but didn't recommend it as the OP had specified A lenses.
I always think about price, and your previous posts in the thread made me think of the new lens. It makes spending over $220 much harder. The FA 35mm f2 used to hold prices down in the same way when it was $299 new. Now, 35mm and f2.4 is not perfect for everyone, but it's close enough to factor into the decision.

QuoteQuote:
I learn something new every time I read posts here, I did not realize that there was an F version of the 28 lens. I'll have to go read more about it - thanks.
When I got my DSLR, you could still get the FA 28mm f2.8 for $300. Most people said that was better than the F version. When it was discontinued, everyone wanted one and prices spiked. The F version was cheap. A couple of years ago, people started to like the F better. I've never used the FA, so I don't know what I'm missing. The designs are much different. It makes me wonder, but I've spent too muc time wonderingabout 28mm and not enough shooting.
12-16-2010, 02:42 PM   #15
Veteran Member
Docrwm's Avatar

Join Date: Sep 2010
Location: Somewhere in the Southern US
Photos: Gallery | Albums
Posts: 11,275
QuoteOriginally posted by Just1MoreDave Quote
I always think about price, and your previous posts in the thread made me think of the new lens. It makes spending over $220 much harder. The FA 35mm f2 used to hold prices down in the same way when it was $299 new. Now, 35mm and f2.4 is not perfect for everyone, but it's close enough to factor into the decision.



When I got my DSLR, you could still get the FA 28mm f2.8 for $300. Most people said that was better than the F version. When it was discontinued, everyone wanted one and prices spiked. The F version was cheap. A couple of years ago, people started to like the F better. I've never used the FA, so I don't know what I'm missing. The designs are much different. It makes me wonder, but I've spent too muc time wonderingabout 28mm and not enough shooting.
The new 35/2.4 is very welcome to me as a new dSLR owner. I haven't been at this long but I have seen prices spike on a couple of lenses just in the past 3 months over what the reviews listed them as having gone for in 09 and early 10, so I know that trends impact price. I also know, from my other hobby watches, that popularity tends to be infectious with collectors and when someone has a particular lens and praises it to high heaven then others are going to go out and search for that lens too. When its a discontinued model that makes prices spike and can happen quickly.

For me, unfortunately, I am realizing that the combination of my eyesight and the nature of the photographs I take most (kids, sports, etc.) I need more Autofocus lenses and fewer manual ones. I read all the reviews of the AF 50s and went in search of one. Finally landed an FA50/1.4 for a price I like and it arrived a hour ago at the office. F50/1.7 vs. FA50/1.4 is a debate I have read about but do not want to get into, because like you said about the 28s and the opinions, I don't own an F50/1.7 so I can't comment on which is better at what f-stop. I'm just looking for a good lens (and wouldn't be sad if it were great) that gets action shots indoors in focus without resorting to ISO6400.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
camera, k-x, lenses, pentax, pentax a lenses, pentax help, photography
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: (3) Vivitar Series 1 70-210mm lenses + 3 Pentax lenses JP_Seattle Sold Items 13 04-23-2010 03:10 PM
Pentax Km and old manual lenses: SMC Takumars & Tamron Adaptall 2 lenses Kendrick Troubleshooting and Beginner Help 10 04-14-2010 03:23 AM
For Sale - Sold: FS: Pentax SF7-body / AF400FTZ / 3 Pentax-F lenses / GENUINE Pentax-accessori frederik9111 Sold Items 7 03-23-2008 03:00 PM



All times are GMT -7. The time now is 09:05 PM. | See also: NikonForums.com, part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top