Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
06-06-2010, 03:34 AM   #1
Forum Member




Join Date: Mar 2010
Posts: 57
Question about using extension tubes for macro

Hi, I'm a happy new owner of a Kx, which is my first dslr, I might add!

I currently have the FA 50 1.4 and the 35 limited macro. Mostly, I like doing candid portraits and landscapes.

I find the FA 50 a bit too short for candid portraits, because you basically need to get pretty close to the person for a nice head and shoulders shot.

With the 35 limited macro, it seemed like a great all-in-one lens that can do landscapes, but also macro. That being said, I'm still wrapping my head around the 35mm focal length (or should I say 52.5mm on FF).

But lately, I've been getting LBA for something longer, such as the FA 77 or the DA 70. The guy at the camera store said that I *could* actually achieve some kind of macro using my existing FA 50 with extension tubes.

So, the basic question is, what're the advantages/disadvantages of using extension tubes for getting macro shots? Is there something I'd really be losing going with the FA50 and macro?

Thank you!

06-06-2010, 03:38 AM   #2
Administrator
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 43,182
For portraits, something around 70-85mm is ideal

Now for the topic at hand: what extension tubes do is essentially lower the minimum focusing distance of your lenses. As a result, magnification increases as well, allowing practically any lens to be used for macro. The downsides include loss of light, setup instability (which results in motion blur), and loss of AF and auto-aperture (unless your tubes have the necessary electrical contacts). A tripod is always needed when using tubes.

Hope this helps!

Adam
PentaxForums.com Webmaster (Site Usage Guide | Site Help | My Photography)



PentaxForums.com's high server and development costs are user-supported. You can help cover those costs by donating. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

06-06-2010, 04:12 AM   #3
Veteran Member
pcarfan's Avatar

Join Date: Sep 2007
Location: Dayton, Ohio
Photos: Gallery | Albums
Posts: 2,960
QuoteOriginally posted by uchinakuri Quote
Hi, I'm a happy new owner of a Kx, which is my first dslr, I might add!

I currently have the FA 50 1.4 and the 35 limited macro. Mostly, I like doing candid portraits and landscapes.

I find the FA 50 a bit too short for candid portraits, because you basically need to get pretty close to the person for a nice head and shoulders shot.

With the 35 limited macro, it seemed like a great all-in-one lens that can do landscapes, but also macro. That being said, I'm still wrapping my head around the 35mm focal length (or should I say 52.5mm on FF).

But lately, I've been getting LBA for something longer, such as the FA 77 or the DA 70. The guy at the camera store said that I *could* actually achieve some kind of macro using my existing FA 50 with extension tubes.

So, the basic question is, what're the advantages/disadvantages of using extension tubes for getting macro shots? Is there something I'd really be losing going with the FA50 and macro?

Thank you!
First of all, you should call the 35 as such, and not as 52.5.

77 would be great for head and shoulder portraits. If you like portraits so much, even the DA*50-135/2.8 is a stellar lens for that. If you have to have the speed, and need the f1.4 you can either try to find the FA*85/1.4 or wait till July and see what the Sigma 85/1.4 is like. If you don't mind manual focus there are tons of choices.

Is 50 wide enough for landscape. If you can have only two lenses, and don't mind f2.8 for portraits, how about the 35 macro and the DA*50-135 (huge lens though).

Extensions tube work fine. But with the 77 I don't like using it much as I think there is a slight loss of IQ for some reason (?), and you lose infinity focus, can only focus on close objects. I love using it with my F135/2.8. It's difficult to find one with AF (I have one) so most likely you will lose AF as well. They are not true replacement for macros at all. You need to do a search for ext. tubes to learn more. Lots of info. here.
06-06-2010, 04:28 AM   #4
Site Supporter




Join Date: Mar 2009
Location: Gladys, Virginia
Photos: Gallery
Posts: 16,247
I don't think there would be that much benefit using your FA 50 with extension tubes (as compared to the DA 35). You could do macro shots from slightly farther away. To use most extension tubes out there, you need to have an aperture ring on your lens (rules out the DA lenses).

I love both the DA 70 and DA* 50-135 for portraits. Both are really excellent in their own way. I don't own the FA 77, but it is supposed to be better than either of those other two. It certainly is faster glass. At the time, I didn't feel like I could afford the FA 77 and so I bought the DA 70 and was satisfied.

Here's a 50-135 snap of my daughter...



06-06-2010, 04:51 AM   #5
Forum Member




Join Date: Mar 2010
Posts: 57
Original Poster
Thanks for all the responses! I love the pentax community!

There do seem to be some rather significant tradeoffs using extension tubes. I admit that I havent wrapped my head around using the 35mm yet and I dont do much macro shooting here in Tokyo. But I expect that I'd be doing macro a lot at the beach (where I go every summer) since I love taking pics of tiny little sea critters that I find under rocks near the shore!

But I wondered if I could get away with letting the 35mm limited go, and just using the FA50 + extension and then getting something longer for portraits, such as the 70/77/85.

The DA70 or FA77 debate seems to be a whole other story though. I readily admit that I'm completely at a loss as to which I would be better served by. The 85mm sigma looks interesting indeed, but also rather pricey...
06-06-2010, 05:46 AM   #6
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,400
you have a lot of mixed comments here.

Hopfully this will clarify things a little.

As Adam said, extension tubes change the minimum focusing distance of a lens, and they work on all lenses, BUT, not all lenses behave the same with extension tubes because the are not specific ally designed to be used as macros. This may explain why the 70mm mentioned in this thread delivers poor results.

Macro lenses are optimized to deliver optimum performance focused in close, and are designed to be flat field lenses so they can be used to copy flat objects. Normal lenses are not designed usually for the same compromises.

Now, for portraits, I personally like longer lenses, my favourite, if you have the working distance needed ISA 135mm , but many people will also offer opinions about anything from 50 mm up. The interest in 50-85 mm lenses is you can get f1.4 lenses with very shallow depth of feild and the working distance is reduced making them better for indoor portraits
06-06-2010, 06:57 AM   #7
Veteran Member
creampuff's Avatar

Join Date: May 2007
Location: Singapore
Photos: Gallery
Posts: 3,955
Well here's a shot taken with the FA 50mm f/1.4 with Kenko AF auto extension tube. Dead easy to use. This was shot hand held for a product shoot.
An extension tube will generally not degrade image quality as there are no optical elements between the lens and camera body. A consequence of the extra extension is light falloff, which affects how bright the viewfinder image is, the camera's ability to lock focus (if one uses an AF extension tube, not applicable for manual focusing) and overall exposure. The minimum focusing distance will be shortened (hence magnification increases), so infinity focus will not be possible with ext. tube attached.

06-06-2010, 07:25 AM   #8
Veteran Member
pcarfan's Avatar

Join Date: Sep 2007
Location: Dayton, Ohio
Photos: Gallery | Albums
Posts: 2,960
Samples to show image degradation.

At MFD (no ext. tube, the whole image).



At MFD (25mm ext. tube)



Note the undefined area in the middle, edges are a bit sharper than the middle.

Now, the crop of the image without the ext. tube.



Now, this does not happen with my F135/2.8 that I tested. Therefore, I think it depends on the lens.

06-06-2010, 10:02 AM   #9
Pentaxian
reeftool's Avatar

Join Date: Dec 2007
Location: Upstate New York
Photos: Gallery | Albums
Posts: 8,156
The extension tube narrowed the depth of field to less than the size of the keys. You will need a precise focus for that lens/tube combo. I think shooting with ext. tubes on a lens brings out the curvature of the glass and some distortion that wouldn't be seen otherwise. A true macro lens is designed for close shooting and won't have that distortion. I purchased a set of M42 ext. tubes over the winter but haven't used them much yet other than a couple of test shots with a 55/2 Tak. Now that I'm done with all the graduations and family get togethers, I'm looking forward to using them. The final picture shows that crops taken with a good sharp lens can do a fine job with a lot of close up shooting. I don't have the DA70 or FA77 but I have noticed that my best portrait shots with my zooms have been in that size range.
06-06-2010, 10:59 AM   #10
Site Supporter
enoeske's Avatar

Join Date: Jul 2009
Location: Surprise, Az
Photos: Gallery
Posts: 1,925
Fly over to my macro folder and leaf through my results. I use a smc (k series) 50mm f/1.4 and vivitar auto extension tubes (36mm, 20mm, 12mm).

QuoteOriginally posted by Adam:
A tripod is always needed when using tubes.
My shots are all hand held



06-06-2010, 11:41 AM   #11
Veteran Member
RioRico's Avatar

Join Date: Jun 2008
Location: Limbo, California
Posts: 11,264
If you can, keep both your 35 and 50, they're great lenses. Meanwhile, there are MANY threads here dealing with macro work. Here's a short summary:

Lenses labeled 'macro' are handy and flexible, and tend to be expensive and good.
Almost any lens can be extended for macros, but some give better results reversed.
And many lenses can be reversed for macro work, but some need extension tubes.
Shorter lenses are for close-in shooting. Longer lenses let you work from a distance.
Autofocus is irrelevant. Much fine macro work is done with old cheap manual lenses.
There are many ways to approach macro work. Study+practice+study+practice...
06-06-2010, 12:02 PM   #12
Pentaxian
Wheatfield's Avatar

Join Date: Apr 2008
Location: The wheatfields of Canada
Posts: 10,157
QuoteOriginally posted by uchinakuri Quote
(or should I say 52.5mm on FF).
No, you shouldn't say that. You aren't working with a full frame camera, and if you were, you would still be working with a 35mm lens (in this instance).

For that matter, have you ever used a 135 format camera, be it film or other?
06-06-2010, 01:42 PM   #13
Veteran Member
RioRico's Avatar

Join Date: Jun 2008
Location: Limbo, California
Posts: 11,264
QuoteOriginally posted by Wheatfield Quote
QuoteOriginally posted by uchinakuri Quote
I'm still wrapping my head around the 35mm focal length (or should I say 52.5mm on FF).
No, you shouldn't say that. You aren't working with a full frame camera, and if you were, you would still be working with a 35mm lens (in this instance).
Exactly. The obscene term "crop factor" (phew...) is meaningful only to someone who thinks in terms of 35mm/135 full-frame cameras. When I shot half-frame (HF) 135, the term was never used; I also shot 9x12, 6x6, and full-frame (FF) 135, and never considered that any was a 'crop' of any other. It's just a matter of learning how different focal lengths and apertures project onto different frame sizes.

What is 'cropped' is the FoV (field of view) aka AoV (angle of view). Perspective and other lens characteristics remain the same. (I won't restart the DoF wars now...) To visualize it all, try this:

Take a full-page magazine picture. Cut it to 4x5 inches / 102x128mm. Now draw a rectangle 60x90mm on it -- that's a 6x9 MF camera 'crop'. Now draw a rectangle 45x60mm on it -- that's a 645 MF camera 'crop'. Within that, draw a 24x36mm rectangle. That's a 135/FF 'crop'. Within that, draw a 17x25mm (APS-C) or 18x24mm rectangle -- the former is your Kx 'crop', the latter is a 135/HF or 35mm cine 'crop'. Inside that, draw a 13x17mm rectangle -- that's a m4:3 or 110 format 'crop'. And inside that, draw an 8x12mm rectangle -- that's about a 16mm cine 'crop'.

This is exactly what happens when you use any specific lens on different formats. Smaller formats just take a smaller slice of the picture. A 35mm lens is still 35mm no matter what it's on. Set to f/4, it remains f/4, no matter what it's on. Smaller formats will impose lower diffraction limits, and different presentations will show more or less detail. But the picture remains the same; only your slice of it changes.

If you're not an old film-user, delete the term "crop factor" from your consciousness.
06-06-2010, 02:27 PM   #14
Veteran Member
Stratman's Avatar

Join Date: Mar 2007
Location: St Louis, Missouri U S A
Photos: Gallery | Albums
Posts: 2,464
Here is a shot with a SMC-M 50mm F1.4 with a 20mm Ext tube attached. VERY thin DOF for sure.

06-06-2010, 03:03 PM   #15
Pentaxian
Transit's Avatar

Join Date: Aug 2007
Location: Whanganui NZ
Photos: Gallery | Albums
Posts: 4,077
QuoteOriginally posted by enoeske Quote
My shots are all hand held
you beat me to it

I used tubes a lot before I got some dedicated macro lenses.
Heaps of fun and well worth it. Used an old Takumar preset 135mm to good effect.
Pete
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!
extension, extension tubes, fa, head, k-mount, landscapes, macro, pentax lens, portraits, question, slr lens, tubes
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Question on extension tubes ismaelg Pentax SLR Lens Discussion 3 11-25-2009 10:09 PM
Question on extension tubes ismaelg Pentax SLR Lens Discussion 1 08-14-2009 08:04 AM
Extension tubes question yeatzee Pentax SLR Lens Discussion 22 05-09-2009 07:41 AM
Question about Pentax Extension Tubes GatorPentax Pentax Camera and Field Accessories 19 12-11-2007 04:52 PM
Question about extension tubes switters Pentax DSLR Discussion 7 12-06-2007 01:21 PM



All times are GMT -7. The time now is 11:01 AM. | See also: NikonForums.com, CanonForums.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