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12-27-2010, 06:36 PM   #1
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Decent macro lens?

Hi I have just recently acquired a Pentax K-X and was wondering if anyone would recommend me a decent affordable(70-120) Macro lens for my camera? Just to mention I'am a complete novice so please be gentle .

Thanks.

12-28-2010, 06:21 AM - 1 Like   #2
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There is macro, and then there is macro. Almost anything labeled MACRO-ZOOM, isn't. Autofocus macro primes are good general-purpose lenses with sharp optics and not-cheap price tags. They are easy to use with flash. And I don't have any, so I can't recommend any. Manual focus manual primes with aperture automation are also good with flash, and are usually a bit cheaper. Macro setups lacking aperture automation are good and often cheap, but tricky to use with flash. I'm a cheap bastard, so I'll just say that it depends on what and how you want to shoot, and how easy you want it.

Various others here will probably recommend a Tamron 90mm, and it's probably within your price range. I use a manual Vivitar-Komine 90/2.8 macro (US$3 but I was lucky) and Pentax Macro-Takumar 50/4 (US$50, lucky again). But mostly I use enlarger lenses on bellows and tubes, all quite inexpensive. Or a Raynox magnifier atop an autofocus lens.

Like I said, it depends on what and how you want to shoot. Still or moving subjects? How close? How much magnification? How important is edge sharpness? Will you shoot for art, for science, for quality control, just to see if you like close work, or what? No single lens will suit in all situations.

A good starting point is with a Raynox DCR-150 or -250 (more magnification with the -250). Good clean optics, and it clips onto most any lens. Put that on an autofocus zoom or prime for easy work, and it costs around US$50-60. See the Raynox galleries here for stunning images. A Raynox will give you a taste -- if you like it, you can decide how much deeper to go. Read the other MACRO threads here for experiences and examples. Have fun!
12-28-2010, 07:01 AM - 2 Likes   #3
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QuoteOriginally posted by kaimarion Quote
Hi I have just recently acquired a Pentax K-X and was wondering if anyone would recommend me a decent affordable(70-120) Macro lens for my camera? Just to mention I'am a complete novice so please be gentle .

Thanks.
Hey kaimarion,

In that price range I would try to find one of these lenses, on ebay or pentaxforums marketplace

Tamron SP MF 90mm F2.8 MACRO 1:1 (72B) Lens Reviews - Pentax Third-Party Lens Review Database (The one RioRico mentioned)

Admiral/Panagor 90mm Macro Lens Reviews - Pentax Third-Party Lens Review Database

Vivitar 90mm f2.8 Macro Lens Reviews - Pentax Third-Party Lens Review Database

Vivitar Series 1 90mm 2.5 Macro Lens Reviews - Pentax Third-Party Lens Review Database

Kiron / Lester A. Dine 105mm f2.8 Macro Lens Reviews - Pentax Third-Party Lens Review Database

Vivitar Series 1 105mm f2.5 Macro Lens Reviews - Pentax Third-Party Lens Review Database

All these lenses are MF and most of them lack the A-setting (you will need to set the aperture manually, and stop down.) If you can find the Lester Dine or Kiron 105 mm with A-setting within your price range, go for it. It is a great lens.

Btw, most 90 - 105 mm macro lenses are sharp and have good bokeh. What sets the price:

Mount: M42 / K / KA? M42 cheapest, K still pretty cheap, KA - tends to drive up the price.

Max magnification: 1:1 lenses are most of the time more expensive compared with 1:2 lenses. But from what I have seen, most 1:2 lenses are just as good, if you can live with less magnification.
12-28-2010, 07:22 AM - 1 Like   #4
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Welcome! :-)

For new macro lenses in the 100mm ish range there are the Tamron 90mm 1:2.8, Pentax 100mm 1:2.8 and the Sigma 105 1:2.8. All these enjoy an excellent reputation and the focal lenght gives a fair working distance (that from the tip of the lens to the object) which helps not to scare insects and such away and also makes it less likely that a shadow from the gear or the user interfere. Of these the Tamron is the cheapest, the Pentax the dearest. All give 1:1 magnification (that is, the image on the sensor is live size).

For a cheaper dedicated macro lens the most easily found options are probably the Cosina 100mm 1:3.5 and the Pentax-M 100mm 1:4. The Cosina has also been sold as Phoenix, Promaster, Vivitar and even Pentax both as MF and AF versions. The build quality of the Cosina is quite plasticky, but optical quality is good for the price. The Pentax-M is of fine build quality, but an MF lens (for macro this is not much of a hindrance IMO, it may limit using the lens as a general purpose 100mm). Both of these lenses can do 1:2 (image is half of the live size on the sensor), the Cosina comes with an add-on lens that brings it to 1:1. These can only be had second hand for around US $100-150.

Of the cheaper ways the Raynox add-on lenses mentioned above are probably the most convenient and results are quite respectable for an investment of US$ 60 or so. Even cheaper ways would be extension tubes and reverse mount adapters, but with these one needs suitable lenses (and a tripod, probably) to go with them for good results and reasonable convenience.

12-28-2010, 07:23 AM   #5
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You can get this one: Cosina AF 100mm f/3.5 macro (Pentax) - Review / Lab Test Report
12-28-2010, 08:02 AM   #6
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All the lenses listed so far are good alternatives.

However I believe the first lens you should consider is the $50 Raynox DCR 150 clip-on to use on your long zoom. If you do not have a long zoom I recommend the Pentax DA 55-300mm.

A good long zoom with a DCR 150 gives an enormous range of high quality image possibilities, Ranging from infinity focus to 1:1 macro for a 200mm lens and 2:1 for a 300mm lens with a reasonable working distance of about 8".

I have some good macro lenses but most often use a Raynox on my long zoom.

Get the Raynox (& long zoom if necessary); after using the combo for a while you'll be able to make an informed decision on what specialized lens to choose. In this scenario the Raynox will not be wasted - you'll use it for a long time as your "just in case" alternative - eg. when I go into the forest with only a long zoom for bird photos, my Raynox is in my pocket "just in case".

Last edited by newarts; 12-28-2010 at 08:10 AM.
12-28-2010, 08:07 AM   #7
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Some good advice already but I'd go with the Raynox 250 - I have a Tamron 90 and a Raynox 250 and if you are just starting out the Raynox can do some amazing work and of course it's very flexible being able to fit on 90% of lenses. It's an inexpensive option and will you almost lose nothing if you don't like it and sell it on.

Another an even cheaper option is to reverse a lense, a 50mm - 100mm would work well, it doesn't have to be anything special, almost any lense will do. You can reverse straight onto the camera (with an adapter) or onto another lense (with another adapter). All it's going to cost you is a few dollars for the adapters - and will give you more than 1:1 magnification.

Beware that the DoF will be very narrow though (especially with the Raynox) and you will require great patience and a bit of practice before you start getting a higher percentage in focus (say 20-30% instead of 1-2%) than out of focus !
12-28-2010, 08:22 AM   #8
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QuoteOriginally posted by Frogfish Quote
...
Another an even cheaper option is to reverse a lense, a 50mm - 100mm would work well, it doesn't have to be anything special, almost any lense will do.
...
The modern lenses without an aperture ring can be inconvenient and working distance is small, though.

12-28-2010, 09:00 AM   #9
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QuoteOriginally posted by Frogfish Quote
Some good advice already but I'd go with the Raynox 250 - I have a Tamron 90 and a Raynox 250 and if you are just starting out the Raynox can do some amazing work and of course it's very flexible being able to fit on 90% of lenses. It's an inexpensive option and will you almost lose nothing if you don't like it and sell it on.

Another an even cheaper option is to reverse a lense, a 50mm - 100mm would work well, it doesn't have to be anything special, almost any lense will do. You can reverse straight onto the camera (with an adapter) or onto another lense (with another adapter). All it's going to cost you is a few dollars for the adapters - and will give you more than 1:1 magnification.

Beware that the DoF will be very narrow though (especially with the Raynox) and you will require great patience and a bit of practice before you start getting a higher percentage in focus (say 20-30% instead of 1-2%) than out of focus !
The Raynox 250 is stronger than the 150 and will work well on a shorter focal length lens.

The Raynox 150 on a long lens will give equivalent results to the Raynox 250 on a shorter lens, the difference being the 150 has a working distance* of about 8.3" (208mm) while the 250 has a working distance of about 4.9" (125mm). The longer working distance of the 150 scares bugs less and makes lighting easier.

Similarly, the major drawback (apart from awkwardness and loss of all automatic functionality) of using reversed lenses as close-up add-ons is a small working distance (less than 2" - 45.5mm.)

Shallow Depth of Field is common to all macro work and is no different for a Raynox type close-up lens than any other macro setup.

Dave

* working distance for an add-on close-up lens is close to the close-up lens' focal length (Raynox 105's focal length is 208mm, and the Raynox 250's is 125mm).

Last edited by newarts; 12-28-2010 at 09:06 AM.
12-28-2010, 10:32 AM   #10
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All correct Dave - but it only cost US$5 to have a go to see if you enjoy macro, rather than US$50 - 60 for a Raynox

Also note though that the DoF when you have a Raynox on IS different to a macro lense alone, it is far shallower (as well as - as you quite rightly said - reducing the max working distance to the subject).

See here for a shot with a Raynox 250 on a Tamron 90 : https://www.pentaxforums.com/forums/post-your-photos/127175-macro-3-bed.html

Joelepp - actually I don't find it inconvenient at all (reversing lenses - but you do have to get very close) - although it certainly isn't my preferred method for macro it got me started before I even bought a macro lense. It is a very good way to get high magnification without paying out more than a few dollars at most.
12-28-2010, 11:19 AM   #11
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QuoteOriginally posted by Frogfish Quote
....

Also note though that the DoF when you have a Raynox on IS different to a macro lense alone, it is far shallower.....
In theory at least there is no difference between DoF for a close-up lens approach to macro (like the Raynox) and a dedicated Macro lens if one takes f-number changes into account.

This is because adding a closeup lens to a primary lens changes the focal length of the combined lenses; in effect it make a "new" lens of shorter focal length. This "new" lens is the same distance from the sensor as the original lens, but since it has a shorter focal length, its image is larger (by the ratio of focal lengths.) Because it has a shorter focal length, its f-number is increased in the inverse ratio of focal lengths.

Consider a lens of 100mm focal length focused at infinity, f-number=4. Adding a 100mm close-up lens to the original makes a "new" lens of focal length 50mm, f-number=2, magnification ratio 1:1. The DoF is exactly the same as that of any 50mm macro lens at 1:1 magnification ratio set at nominal f:2.

I guess you could say that since the "new" lens has a lower f-number than the original 100mm lens, it has less DoF (than something - what?) but I think this is misleading as it is indeed a new lens.

What I mean by "no different" is inherent in the DoF equation for macro work:

DoF=2CN(1+1/m)/m where C=Circle of Confusion", N = F-Number, and m = magnification.

This equation doesn't care if the lens in use is a "macro" lens or a construction of other lenses.
12-28-2010, 11:51 AM   #12
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Some good recommendations above (besides mine!) and notice that a few of us propose a Raynox to start with. I did NOT suggest extension (tubes+bellows) nor lens reverse stacking, because those are trickier for beginners, and your budget can accommodate something more convenient.

But those less expensive options ARE good, depending on what you want to do. I often use cheap sharp enlarger lenses on extension for both macro and non-macro photography. A decent extension setup can be assembled for US$20-50, a superb setup for under US$100. A variant of this is to use a cheap mount-reversal ring to turn any manual-aperture lens into a sharp flat-field close-up lens. It still requires extension for magnification, though.

Lens stacking, using a cheap thread-reversal ring and a manual-aperture lens, can provide GREAT magnification. The lens set on the camera is the PRIMARY. The lens that is reverse-stacked on it is the SECONDARY. Magnification is merely the ratio of their focal lengths. So a 240mm primary stacked with a 24mm secondary gives 240/24= 10X magnification -- and now you are in the realm of MICRO photography.

The problem with any lens reversal is working distance. Reversed, as newarts said, your working distance is 45.5mm, under two inches. That may be fine for shooting stamps, coins, dead bugs, etc, and not-so-fine for shooting live spiders and wind-blown flowers.

I'll say it again: It depends on what and how you want to shoot, as well as your budget and skills. For greeting-card-quality floral shots, a cheap macro-zoom that reaches 1:4 (0.25x) magnification may do fine. For scientific documentation of the inner anatomy of fleas, a 10x stack like I mentioned above may be needed. Your answer is probably somewhere in between.
12-28-2010, 11:57 AM   #13
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That is an interesting read Newarts and it will take me some time to investigate and digest the maths and see how that applies to real life applications.

However, the Raynox 150 and 250 are respectively +4.8 and +8 diopters and the DoF, of the 250 especially, is very shallow - the greater the magnification of the lense (e.g. a macro lense) the shallower the DoF when adding the Raynox to it. Another factor influencing the DoF is the distance between the front element of the lens in use and the Raynox - with the Tamron 90 Di that I use for example, the front element is recessed, thereby increasing the magnification (and so reducing the DOF further still).

All that said, I don't actually need the maths to tell me that - in practical use I can see immediately that the DoF has been greatly reduced when the Raynox is added to the Tamron. The effect will naturally vary from lense to lense (or more accurately from FL to FL) but is always a lot less than just the lense by itself (obviously, but better said so that nobody new to macro can misinterpret this).
12-28-2010, 12:54 PM   #14
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QuoteOriginally posted by Frogfish Quote
....
All that said, I don't actually need the maths to tell me that - in practical use I can see immediately that the DoF has been greatly reduced when the Raynox is added to the Tamron. The effect will naturally vary from lense to lense (or more accurately from FL to FL) but is always a lot less than just the lense by itself (obviously, but better said so that nobody new to macro can misinterpret this).....
I do not doubt your observations, but think you may not be taking enough into account. A couple important things change when you add the Raynox to your Tamron; The magnification increases (the focal length decreases) and the f-number decreases.

To fairly compare the effect of the Raynox on Dof you might:

1) Put the Raynox on the 90mm macro lens, focus at infinity & take a DOF test shot of a tilted ruler or laptop screen. With the Raynox 250 you should get a magnification of something less than 90/125 = 0.72x (it is less than 0.72 because the Raynox is not right up against the 90mm lens.)

2) Remove the Raynox and adjust the lens for the same magnification and exposure (setting for the same exposure by keeping shutter speed constant, ISO constant, and changing f-number compensates for any change in f-number I think.) Compare the photos.

Theory predicts the same DoF for both shots.

I don't have my 90mm macro lens with me but do have a good 50mm macro lens and a Raynox 150. I'll try a similar experiment and share the results.

Last edited by newarts; 12-28-2010 at 03:54 PM.
12-28-2010, 03:34 PM   #15
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Thanks everyone for your help it is very much appreciated especially because of how helpful a lot of the posted information has been.


To answer RioRico's question I would be using the lens mostly for taking pictures of live insects and close up shots of plants. It would be somewhat important that I did not have to be right up at the subject to take the picture as some of the insects I will be dealing with aren't too friendly when you get right up in their face.

Anyway I will be checking out all the lenses that have been mention in this thread so far and hopefully I'll be able to pick one.
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