Go Back   Steve's Digicams Forums > Digital SLR and Interchangeable Lens Cameras > Pentax Lenses

Reply
 
Thread Tools Search this Thread
Old May 9, 2010, 12:04 PM   #1
Member
 
Join Date: Feb 2010
Posts: 90
Default your opinions/ideas on lenses

hey all, asked what camera to buy a few weeks back, was thiking of a cannon eos 50d or 500d. cant even remember now, but was introduced to the k-x. the k-x should be arriving at my door in a day or two. so now comes the next part. lenses. the 18-55mm lense comes with the camera, i opted out of getting a 2 lense kit as i fancied getting some other bits and bobs instead.

so..

does anyone have any ideas on what lenses i can get for the following

only going to get some 2nd hand ones, as i dont wanna buy something top notch straight away. would rather play about with some lenses first, then when i think ive had enough practice and can afford another half a grand lol.. ill buy something better.

i do wanna do macro. i dont mind using extention rings etc etc, as long as it works to a reasonable extent. or just an ok macro lense thats cheap 2nd hand. (doubt they exsist tho) i would love to do 1:1.. but 1:2 would be cool. just not sure how it would work exactly with the rings etc

a lense i can use for my star pictures. this comes down to 2 types in my eyes. a normal lense. id say anything up to 300mm. so i can use it for a normal to mediaum range use lense, and for stars. (the 18-55 im sure will be ok for everyday use tho, so it would prob have to be a pretty gd one for my stars. maybe even a wide angle lense... not sure.. why im asking lol)

or

a telescope with an m42 adapter for pics of moons etc. have never tried anything like that mind, so that would be new. (this isnt something i need tho. just an experiment. so this one is last on my list)
(if youve not seen them..... http://cgi.ebay.co.uk/300-600-960mm-...item2306d74538)


now for money... for 2 lenses (or a mix and match with the macro etc) ive only got about 150-200 $200-400. maybe a bit more at a push. but just wanna see what you guys have to offer with your super knowledge
jasonholland89 is offline   Reply With Quote
Sponsored Links
Old May 9, 2010, 5:47 PM   #2
Senior Member
 
mtngal's Avatar
 
Join Date: Nov 2005
Location: Frazier Park, CA
Posts: 16,056
Default

I can't help you with your astrophotography, I've never tried it.

As far as macro - if you can find one, look for a Phoenix 100 mm macro. They are light-weight plastic but the optics are very, very good. When they were still being made they went for $100 - 150 depending on if it was AF or not. I wouldn't may more than that used. I have the Vivitar Series One 105 macro that's excellent but they've become a "cult" lens and getting top dollar now. I was happy to spend $250 on mine (unsold old stock, so unused) but I'm not sure they are worth the $350 or more they seem to be going for now. On the other hand, it is really sharp and might do double duty for you if you can use that focal length for your stars.

Many zoom lenses that say "macro" aren't really macro. I have a Kiron 80-200 "macro" lens but it only does 1:4, about the typical cut-off for the "macro" name on zoom lenses. The Tamron 70-300 can do 1:2, so that might be a better option.

If you want a 300 prime, check out the A*300 or the M*300 - they may be just out of your price range, but they are worth every penny.

A really inexpensive option for macro would be to pick up one of the K-mount Takumar 135 mm f2.5 (I think that's the speed). It's a lens with a very poor reputation and can be had for well under $100. It's fairly low contrast and it has no coatings so you'll get lots of flare in certain situation. So why would I mention what sounds like a lousy lens? Mine is very sharp. Being low contrast/relatively low saturation it's fine for flowers where you can lose detail to high contrast/extra saturation. I've used mine with a reversed 50 mm for some things inside (but dof is tiny so it's not that great outdoors). I've also used it successfully with an extension tube. Just don't try taking sunsets with it - they will look like mud. They were originally a kit lens for the ME and so there's sample variation to take into consideration. But it's worth taking a flyer on as long as you can pick it up cheaply.
mtngal is offline   Reply With Quote
Old May 9, 2010, 8:15 PM   #3
Senior Member
 
shoturtle's Avatar
 
Join Date: Dec 2009
Location: Frankfurt AM
Posts: 11,348
Default

tamron 70-300 DI LD macro at 1:2, you will get 1:1 with an extension tube. New the lens is about 160, so it will be pretty cheap 2nd hand.
__________________
Super Frequent Flyer, no joke. Ex Patriot and loving it.
Canon Eos 60D, T1i/500D, Eos1, Eos 630, Olympus EPL-1, and a part time Pentax K-X shooter.
shoturtle is offline   Reply With Quote
Old May 10, 2010, 6:41 AM   #4
Senior Member
 
Join Date: Mar 2010
Location: Holland
Posts: 105
Default

I just recently bought the k-x and also wanted to go for a budget macro solution.
Following the advice of the always helpful members here at Steve's I decide to buy an old smc M 50mm 1.7 (goes for a very good price secondhand and often comes together with old pentax slr's like the ME) together with a vivitar teleconverter which is not very expensive as well. I got lucky and got myself a great deal because I also got some extension rings with it. It's great fun playing around with that macro set-up until budget allows for a real macro lens. In addition you can use the 50mm reversed on another lens for extra macro
I've heard a lot of positive things about the phoenix/vivitar/promaster 100mm macro, I've been searching for it also but it seems very hard to get for the pentax mount (I've been searching for a month, and I've found only 1 now.. Still deciding whether I'm going to buy it though.

And like shoturtle said the Tamron 70-300 is a very good budget option.. and gives you a multipurpose lens.

Probably the *300 primes would be out of your budget... and spoiling with lens quality you never want to live without
__________________
Pentax K-x, DAL 18-55, Tamron 70-300, Sigma 10-20
JC de Jonge is offline   Reply With Quote
Old May 10, 2010, 8:27 PM   #5
Senior Member
 
RioRico's Avatar
 
Join Date: Aug 2008
Location: In mountainous California or Arizona or Guatemala or somewhere.
Posts: 224
Default

Astrophotography is more about (equatorial) mounts than lenses. You'd do best to buy a telescope on a tracking mount -- I got a fairly new Meade (computer controlled) at a yard sale for US$75. I haven't hooked a camera to it yet, but soon, soon...

Macrophotography: the expensive way is to buy a fancy macro lens. I got a great M42 Vivitar 90/2.8M for US$3, but that was a lucky hit. There are various cheap ways to get to 1:1 and beyond. For instance: M42 macro tubes, a M42-PK adapter (it can be the cheap safe flanged type), and a superb cheap Industar-50 lens. That set can be had on eBay for under US$40, shipped. Put the 50mm lens on 50mm of extension and you're at 1:1.

The cheapest way: get ANY prime lens from ANY maker, so long as it has an aperture ring; and a mount reversal ring to fit its thread. 55mm threads are pretty common, so a 55mm-PK mount reversal ring (cost under US$10) will take that Canon or Nikkor or Minolta glass you picked up for another ten bucks. You won't get to 1:1 but reversed optics are almost always quite sharp.

Ah, but 1:1 ain't enough, you say? Well, put that 50mm lens on 100mm of tubes, and you're at 2:1 -- but the image is a bit dark, and those tubes are getting shaky. What to do?

Buy several prime lenses, all with 49mm front threads (an old Pentax standard) and aperture rings. A decent 135/2.8; a good cheap 55/2 or 58/2; decent 35/2.8 and 24/2.8; and a 49mm thread reversal ring. You sholuld be able to buy all these for well under US$150. Mount the 135 on your camera. Screw the ring on. Now stack one of the other lenses, reversed. Which lens? Depends on the magnification you want. It's a strict ratio: Mag = L1(primary) / L2(secondary). So 135/58= 2.3:1 and 135/35= 3.9:1 and 135/24= 5.6:1 zowie!

This trick has been a favorite for many decades. Cheapskates skip the ring and just use gaffer's tape to hold the lenses together, nose-to-nose. NOTE: leave the primary's aperture wide open to avoid cropping; use the secondary's aperture to control exposure.

So those are the cheaper simpler ways to do quality macro work. Other ways: bellows (more flexible but clumsier); diopter lenses (not the best image quality); adapters like the Raynox DCR-250 (simple; good quality; maybe US$50; but not 1:1); or a nice cheap used macro lens (but you won't get past 1:1).

Other considerations: short macro lenses, and reversed lenses, require that you are CLOSE to your subject. A short macro lens, like 28-35mm, fills the frame easily, but you must be CLOSE. These are thus best suited for studio work. A longer macro lens, like 90-105mm, lets you work a few inches away, and thus is preferred by many field shooters. I used to put a 400mm tele on a long bellows, all fitted to a shoulder mount, to take closeups of rattlesnakes from a safe distance.

For more, see http://en.wikipedia.org/wiki/Macrophotography
RioRico is offline   Reply With Quote
Old May 11, 2010, 12:51 PM   #6
Member
 
Join Date: Feb 2010
Posts: 90
Default

well ok, lots of info here. had a look at the tamron 70-300. might buy one of these anyway as it will prob be a good allrounder, as to wther i buy it first or not, im not sure yet.

as for the astonomy, the telesope would be for single images, such as the moon or a small group of stars, that is an experiment i wanna try in time, what i really wanna do is what ive done before, a shot of the night sky. so i need i guess, a lense with a small numbered, or high apature. i believe?

as for the do it yourself macro, that just confuses me with the last comment. it sounds good, but when i search for some of the things, if i added it together it would cost way over half a grand from what ive found. so any chance you can shed more light? or even a link to something so i can start from there? call me a noob if you will... lol
jasonholland89 is offline   Reply With Quote
Old May 11, 2010, 4:36 PM   #7
Senior Member
 
RioRico's Avatar
 
Join Date: Aug 2008
Location: In mountainous California or Arizona or Guatemala or somewhere.
Posts: 224
Default

Quote:
Originally Posted by jasonholland89 View Post
as for the astonomy, the telesope would be for single images, such as the moon or a small group of stars...
Luna when full is BRIGHT, almost like daylight; groups of stars are quite dim; they take totally different approaches. Gargle around for ASTROPHOTGRAPHY and LUNAR PHOTOGRAPHY for details.

Quote:
as for the do it yourself macro, that just confuses me with the last comment. it sounds good, but when i search for some of the things, if i added it together it would cost way over half a grand from what ive found. so any chance you can shed more light? or even a link to something so i can start from there? call me a noob if you will... lol
These are SOLD+SHIPPING prices I've seen on eBay in the last few days:

* mount reversal ring or thread reversal ring: < US$10 each
* M42 Industar-50: ~US$25; macro tubes: ~US$6/set; flanged M42-PK adapter: ~US$6
...So the lens + 2 sets of tubes + adapter = ~US$45
* decent manual 24mm, 35mm, 50-58mm, 135mm primes: < US$25 each

If acquiring a batch of lenses for stacking seems worrisome, just start with the Industar+tubes, or any decent manual lens in the 35-58 range and a mount reversal ring and/or tubes. Just last night I saw several superb Takumar 50/2's sell for under US$20. And it's hard to beat a Helios-44 58/2, now selling (shipped) for ~US$25. Look for brands like Takumar (Asahi Pentax), Vivitar, Mamiya, Ricoh, Sears, Focal, Jupiter. If you wonder about any specific lens, don't be afraid to ask questions here.
__________________
Too many film+digi cams+lenses, oh my -- Pentax K20D, ZX-M, M42's, P&S's, more
The opposite of LIBERAL is not CONSERVATIVE, but ENSLAVED.
RioRico is offline   Reply With Quote
Old May 12, 2010, 11:52 AM   #8
Member
 
Join Date: Feb 2010
Posts: 90
Default

what about this lense?

anyone else know about thing about it. also researching the lenses for starts etc... good lenses for star pics generaly have these kinda specs .... (unfortunately canon but you get the idea)

Canon EF-S 18mm-55mm f/3.5 - 5.6 IS Zoom ($170) - ok wide open at all focal lengths, better when stopped down one stop
Canon EF 17mm-40mm f/4 L USM Zoom ($750) - ok at f/4, very good at f/5.6
Canon EF 24-105mm f/4 L USM IS Zoom ($1,100) - ok at f/4, very good at f/5.6
Canon EF 24mm f/1.4 II L USM ($1,700) -
taking that into consideration, would this lense be of use to both macro if i tried using the method riorico went into more detail, and my stars etc.

anyone know any more about it. tried googling it but bost things ive found are arguments saying it doesnt exsist lol

http://cgi.ebay.co.uk/ws/eBayISAPI.d...tchlink:top:en
jasonholland89 is offline   Reply With Quote
Old May 12, 2010, 1:11 PM   #9
Senior Member
 
RioRico's Avatar
 
Join Date: Aug 2008
Location: In mountainous California or Arizona or Guatemala or somewhere.
Posts: 224
Default

Quote:
Originally Posted by jasonholland89 View Post
what about this lense?
The Tokina 28/2.8 you linked to is a nice lens, but I think the seller wants too much money. I've seen good 28's sell for well under US$50 in the last couple days.

The lenses you listed are all Canon. Canon lenses won't work on a Pentax Kx. It might be possible to find an adapter, but the adapter would lower image quality noticeably. Canon lenses can be used on a Pentax ONLY for macro shooting, usually reversed/stacked -- they're otherwise useless. And many much less expensive lenses are just as suitable.

The critical factor here is called register or registration distance or working distance - the distance from the lens to the image plane (film or sensor). A lens with a long register (like Pentax or Nikon) can be used on a camera with a short register (like Canon or Leica). But a short register lens CAN'T be used on a long register camera, because it can't focus anywhere near infinity. And there are better ways to spend hundreds or thousands of dollars, than on a lens that only focuses for extreme close-ups.
__________________
Too many film+digi cams+lenses, oh my -- Pentax K20D, ZX-M, M42's, P&S's, more
The opposite of LIBERAL is not CONSERVATIVE, but ENSLAVED.

Last edited by RioRico; May 12, 2010 at 1:15 PM.
RioRico is offline   Reply With Quote
Old May 12, 2010, 1:26 PM   #10
Member
 
Join Date: Feb 2010
Posts: 90
Default

ooh i wasnt showing you these lenses to buy, ignore the canon part, it was simply the specs i was showing. eg 24mm f1.4 etc etc,

might see if i can find that lense any cheaper tho. but thats the kinda spec i think im gna need for my star pictures.

Last edited by jasonholland89; May 12, 2010 at 1:29 PM.
jasonholland89 is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 6:21 PM.