Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
08-19-2011, 07:31 AM   #1
New Member




Join Date: Mar 2011
Photos: Gallery
Posts: 20
[langtitle=tl]50mm A f1.7 any good for macro photography?[/langtitle]

just wanted to ask you guys if the 50mm-A f1.7mm reversed w/ extension tubes would yield great results for macro

i heard that this lens has sticky aperture ring? is this true? can someone enlighten me =)

any other lens recommendations?

thanks =)

08-19-2011, 08:38 AM   #2
Veteran Member
RioRico's Avatar

Join Date: Jun 2008
Location: Limbo, California
Posts: 11,264
Yes, the A50/1.7 will deliver sharp images when reversed. I have not heard of a sticky ring problem. You should know that reversed, the lens' working distance will be very close, around 45mm. This is fine for studio work, not so good for outdoors shooting.

What you get by reversing a lens are 1) edge-to-edge flatfield sharpness, and 2) the very close working distance. This is fine if you intend to shoot flat subjects like postage stamps. If you will shoot rounded objects like insects or flowers, you might want a longer, non-reversed lens. Something like a 105/2.8 on extension tubes will let you work further from your subjects.

So your decision may depend on how you shoot, how close you wish to work. Good luck!
08-19-2011, 09:02 AM   #3
Veteran Member
ytterbium's Avatar

Join Date: Jan 2008
Posts: 1,076
I use my Pentax-F 50/1.7 non reversed with macro rings. Quite well.
What magnification are you after?

I don't know if i reached 1:1, but it certainly was close (various magnifications):










But since it's a fast lens, sometimes i feel like im getting too much stray light that decrease contrast (can be fixed in pp). Sharpness is good.
08-19-2011, 09:22 AM   #4
Site Supporter
boriscleto's Avatar

Join Date: Dec 2009
Location: Liverpool, NY
Photos: Gallery
Posts: 12,870
QuoteOriginally posted by RioRico Quote
I have not heard of a sticky ring problem.
I think this is what the OP is referring to.

https://www.pentaxforums.com/forums/pentax-beginners-corner-q/15209-how-fix-s...mm-f1-7-a.html

https://www.pentaxforums.com/forums/maintenance-repair-articles/88051-pentax-...ng-repair.html

08-19-2011, 09:35 AM   #5
Loyal Site Supporter
pacerr's Avatar

Join Date: Jan 2008
Location: Henry, TN
Photos: Gallery | Albums
Posts: 2,910
QuoteOriginally posted by merdenoms Quote
I heard that this lens has sticky aperture ring? is this true? can someone enlighten me =)
You may be referring to a tendency of all of the lenses with plastic aperture rings to "get sticky" or suffer some wear over time if the lubricant hardens, if it gets dirty or it's used frequently in the manual aperture mode over a long period of time. This occurs where the tiny, spring-loaded ball (the one everyone looses the first time they disassemble the lens!) rubs along the "click detents" in the aperture ring.

Since many of the SMC-A lenses sold with AE-capable bodies have never been taken out of the AE detent, hardened lubricant is often the culprit and an easy DIY fix. (See links above) This irritating condition normally has no adverse affect on auto-mode use in the 'A' position.

As RR said, a reversed 50mm lens is a rather specialized item best reserved for flat field subjects, but any of the SMC 50's used with either extension rings or the Vivitar Variable Macro 2X TC are sure to give excellent results. I like the 50/1.7 with an old AE-capable 2X TC with the optics removed as a no-hassle kit that combines both close-up and fast-fifty opportunities in a pocket-sized package at a third the cost of most 90mm macro lenses.

This is an excellent use for one of the $10 SMC-A 50/2.0. At f4 and above I can't tell the results of the 2.0 from the 1.7 or 1.4 in actual close-up use anyway.

A close-up combination that allows a comfortable stand-off distance also facilitates good lighting and allows a short lens hood which can benefit overall contrast.

H2

Last edited by pacerr; 08-19-2011 at 09:41 AM.
08-19-2011, 10:35 AM   #6
Senior Member




Join Date: May 2011
Location: Denver, CO
Posts: 159
would a reversing ring be the best way to go about flipping around this lens? I love the sharpness of the pentax-m SMC 50mm when it's used as intended, so I would love to try it as a macro. I tried just putting an extension tube on it, but that didn't work too well.
08-19-2011, 10:39 AM   #7
Veteran Member
RioRico's Avatar

Join Date: Jun 2008
Location: Limbo, California
Posts: 11,264
QuoteOriginally posted by pentaxk1000denver Quote
would a reversing ring be the best way to go about flipping around this lens? I love the sharpness of the pentax-m SMC 50mm when it's used as intended, so I would love to try it as a macro. I tried just putting an extension tube on it, but that didn't work too well.
A 49mm-PK mount reversal ring will give you edge-to-edge flatfield sharpness and a very close working distance. For magnification, you'll still need a bit of extension. I assume you're using PK macro tubes -- cheap (ordinary) or expensive (AF or A-type)? How didn't it work too well?
08-19-2011, 05:20 PM   #8
krp
Veteran Member
krp's Avatar

Join Date: Oct 2010
Location: Illinois
Photos: Gallery
Posts: 470
I have used the a 50mm 1.7 on extension tubes and it's very sharp. Here's a sample:


But I've decided extension tubes are just too hard to use. You have to use the green button which doesn't always expose correctly and the viewfinder can get really dark. I just bought a 2x 'A' teleconverter and plan to take the glass out. Hopefully that will make macro a lot easier. Also, here's my favorite shot when I had the A 50mm f2 with extension tubes:



08-19-2011, 05:28 PM - 1 Like   #9
Veteran Member
yeatzee's Avatar

Join Date: Feb 2009
Location: Temecula
Photos: Gallery | Albums
Posts: 3,675
yes reversed it should be fantastic, just like my meager broken m 50mm F/1.7 was

ex.


08-19-2011, 05:34 PM   #10
Veteran Member
TOUGEFC's Avatar

Join Date: Nov 2009
Location: Brisbane
Photos: Gallery
Posts: 3,561
It will be fine I have the A 50 f/1.7 too, im not much of a macro shooter but I do use for reverse macro it produces excellent results-
08-19-2011, 05:51 PM   #11
New Member




Join Date: Mar 2011
Photos: Gallery
Posts: 20
Original Poster
thanks brothers for the prompt reply.. much appreciated

i'd be shooting butterflies, plants and spiders =)

what flash setup would you guys recommended?

Last edited by merdenoms; 08-19-2011 at 05:56 PM.
08-19-2011, 08:33 PM   #12
Veteran Member
yeatzee's Avatar

Join Date: Feb 2009
Location: Temecula
Photos: Gallery | Albums
Posts: 3,675
QuoteOriginally posted by merdenoms Quote
thanks brothers for the prompt reply.. much appreciated

i'd be shooting butterflies, plants and spiders =)

what flash setup would you guys recommended?
Any "modern" metz w/ an L bracket and mini ball head and PTTL cable
08-19-2011, 09:21 PM   #13
Veteran Member
Laurentiu Cristofor's Avatar

Join Date: Nov 2009
Location: WA
Photos: Albums
Posts: 3,044
QuoteOriginally posted by RioRico Quote
If you will shoot rounded objects like insects or flowers, you might want a longer, non-reversed lens.
Actually a flat field will help with anything, even with insects (think of flat insect wings or long and straight insect bodies). Field curvature will never be preferable unless you shoot the inside of a bowl - the problem is that natural objects will usually have convex surfaces, not concave.

Field curvature can actually be quite tricky for macro. I remember that the adaptall 80-210 had really strong curvature when I was using it on extension tubes and that was making it hard to get images of dragonflies in nice focus. I couldn't just align myself with the insect and expect that most of its body would come in focus.
08-20-2011, 09:04 AM   #14
Senior Member




Join Date: May 2011
Location: Denver, CO
Posts: 159
I guess the flat field was where I was having a hard time with the extension tube. this is the best photo I got but focusing was nerver-racking. I'm also shooting 100% manual on film, I don't know if that makes a difference or what (I assume you guys with auto focus can't really use it when there's an extension tube involved), but it's not easy! the pics above of the spider and mantis are amazing. the snowflake one too. really nice shots.



edit: oh yeah, and it was outdoor and handheld too. wind and no tripod made this virtually impossible.

Last edited by pentaxk1000denver; 08-20-2011 at 09:11 AM.
08-20-2011, 10:11 AM   #15
Veteran Member
RioRico's Avatar

Join Date: Jun 2008
Location: Limbo, California
Posts: 11,264
QuoteOriginally posted by pentaxk1000denver Quote
I guess the flat field was where I was having a hard time with the extension tube. this is the best photo I got but focusing was nerver-racking. I'm also shooting 100% manual on film, I don't know if that makes a difference or what (I assume you guys with auto focus can't really use it when there's an extension tube involved), but it's not easy!
< ... >
edit: oh yeah, and it was outdoor and handheld too. wind and no tripod made this virtually impossible.
Yeah, it's tough on film without CIF. Also it's very tough shooting with wide-open aperture and available light. Some possibilities here:

* An A-type macro tube set, or (cheaper) a couple used A-type TC's with the glass removed, with a non-reversed A-type lens like your A50/1.7. Such TC's are usually about 25mm thick (and mine cost an average of US$15 each on eBay) so two of them put you at 1:1 magnification. This setup supports pTTL flash and allows you to stop down for thicker DOF.

* A Raynox DCR-250 corrected closeup adapter (probably around US$65) with your A50/1.7. Same benefits as the above, and the Raynox doesn't eat light as extension does.

Reversing a lens means you MUST work very close; it is best for studio work, not out in the field, especially not without a tripod.
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!
k-mount, lens, macro, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Nature smc PENTAX DA 35mm F2.8 Macro Limited fredric Post Your Photos! 12 07-02-2011 01:55 PM
Macro Lens K-x Lost In big space. McDunk Troubleshooting and Beginner Help 6 04-27-2011 12:43 AM
Back focus sur Pentax 50mm f:1.4 SMC FA loule Pentax SLR Lens Discussion 6 10-12-2010 08:57 AM



All times are GMT -7. The time now is 09:29 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