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08-26-2007, 12:41 PM   #1
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Answer to Macro Question.

This is a follow up to a question asked of me by a new user. The thread he created has morfed into a discussion of macro shooting so I decided to post another thread with the correct title so others could find it and add info.

The previous thread is here:
https://www.pentaxforums.com/forums/pentax-dslr-discussion/11029-potential-new-pentax-user.html

A new additional thread is here:
https://www.pentaxforums.com/forums/pentax-photography-knowledge-base/24622-m...l-bellows.html

And the question that was asked was:
Since we're on the topic of macro, what are the various relationships between length of extension tubes to reversing the lens and working distances? From my understanding, just adding an extension tube equal to the focal length of the lens allows for 1:1, am I correct? But how close is the working distance now? What about extension tubes AND reversing the lens? How much magnification can I get with that setup, and what would that working distance be? I've had trouble searching for these answers myself.

I had suggested (budget macro setup) that "gerbilbox" consider a decent 50mm M or A (A better for all around use because of the greater functionality for general shooting) and a set of extension tubes or a 2 x converter that features a continuous focus helicoid for Macro shooting from 1:30- 1:1.

With a 50mm Lens, 50mm of extension gives 1:1 macro shots. Most Extension tube sets are between 50-60 mm total. They can also be stacked with more tubes to offer greater close up ability but there is a noticeable fall off in light intensity with each extension section added. Another option is a Bellows. K mounts are hard to come by but M42 screw mounts are more common. Add a Screw to K mount adapter to the camera end (or a T mount) and buy a screw mount lens between 50 and 100mm. Most bellows units extend from 130 to over 200mm. I'd recommend a 100-135mm lens as the bellows extends enough to get better than 1:1 and a longer lens will give you a greater working distance for a light source etc. With a 50mm lens you'll be right on top of the subject. There are tons of 135mm f 2.8 lenses that will do the job from Pentax, Ricoh, JC Penny, Sears and so on and some only sell for $20.00.

With any macro setup that is approaching 1:1 or greater a tripod or other stabilizing mount is required fr sharpest results. Any camera shake is going to blur the picture even slightly. I mount a focusing rail on my tripod then mount the camera/macro setup to the focusing rail (around $50.00) that way I just set the focus on the lens and use the focus rail dial to micro focus on small things. With macros from 1:2 down to 1:4 you don't need to be so elaborate and a tripod is more than enough.

I tried and didn't like reversing a 50mm because I found a fair amount of corner softness in the pictures. It works well but IMO has some limits. Focusing, aperture control etc.

Anyway that's what I do. Others may use different tools and hopefully will add their thoughts to the discussion.

Here's a good article outlining much of the macro details that may fill in some blanks.

Macro photography

and:

Macro Adapters BR-2A/BR-5

For the techie:

http://xoomer.alice.it/ripolini/Close_up.pdf


Last edited by Peter Zack; 07-28-2008 at 11:11 AM.
08-26-2007, 01:16 PM   #2
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Just an FYI: A 50mm lens focused to infinity with 50mm of extension tubes gives 1:1. If focused closer than infinity, you get even better magnification, although the difference between a 50mm at infinity and at minimum focus is pretty negligible once you have 50mm of tubes on it.
08-26-2007, 01:44 PM   #3
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You're right but I never bothered to calculate the difference. Looking through the viewfinder It would be the increase is around 10% more than 1:1.

Another resource for info on some of these parts is found here:

Pentax Close-up Accessories

As for the working distances as well a 50mm with 50mm of extension is going to be under 6 inches and a 135mm will offer about double the working distance but needs more extension to get 1:1. The ratio is:
50mm lens + 50mm of extension = 1:1 ratio
100mm lens + 100mm of extension = 1:1 life size
50mm lens + 100mm of extension = 2:1 or double life size
50mm lens + 25mm of extension = 1:2 or half life size
28mm + 25mm of extension = roughly life size

As for a cheap way to make your own extension tube setup. buy some cheap K mount 2 x converters and take the glass out. Stack as many as you need and these often sell on Ebay for $20.00 each. 2 should do to get close to 1:1 for a 50mm.

Check this deal out although I don't know if they are M42 or K mount.

eBay.ca: LOT OF 3 BOXS OF PENTAX LENS EXTENDERS (item 130146706992 end time 26-Aug-07 17:53:31 EDT)

Last edited by Peter Zack; 08-26-2007 at 01:50 PM.
08-26-2007, 04:42 PM   #4
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If you're OK with completely losing aperture control, the $15/set eBay extension tubes from places like Fotodiox work well at a dirt-cheap price.

The TC cannibalism trick works well if the TCs pass through aperture info though.

08-26-2007, 04:57 PM   #5
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Actually the 2 x tc's don't have to pass the info through. It's great if they do but not required. Most extension tubes don't as well. You simply shoot in manual and manually adjust exposure. Adjust focus wide open and then stop down, take a meter reading and adjust as needed. Takes some practice and getting used to a particular setup/ combination but in fairly short order you're up and running. I've done it many times with a K10D and it should be no issue with a K110D in manual as well.
That being said If you're trying to shoot the fast moving things like a Bee on a flower then this is a bit of a slower setup to use and will take some practice to get good shots. This setup is better for still life shots etc.
For that fast insect etc. a dedicated macro lens is the best route.

I got a set of those cheap Hong Kong tubes and they are fine, I still have and use them. They had an odd opening in the lens mount and I put a little black tape over that. Now they are light tight and work fine.

Last edited by Peter Zack; 08-27-2007 at 06:02 AM.
08-27-2007, 05:18 AM   #6
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Over the summer holiday, my sixth grade daughter for a school project undertook creating some crystals. When she got done with the project, she came to her dear old doting shutterbug papa and asked for pictures of them to include in the report.

The things were about 2~3mm in size and I was ever so glad that I had spent $20 on a set of M42 extension tubes.

I splayed out the legs on my tripod to get it within a few inches of the floor, mounted up a Takumar 55/1.8 on 57mm of tubes and went to work. The depth of field was so shallow that it was impossible to get the entirety of the tiny crystals all in focus at once. In hindsight, I should have shot it from farther away with a longer lens.

Here's a 100% crop of the ruler we included in some of the shots for scale. The distance between each mark is one millimeter.



f16 at 4 seconds, with ceiling bounced flash.
08-27-2007, 11:06 AM   #7
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Thanks for the answers Peter!

I think what I really need to do is to try different setups myself. I think I'll go with reversing the lens first since that's the cheapest way and, from what I remember, its offers greater than 1:1 magnification; I have some really tiny critters I want to photograph. But then again, finding extension tubes on the cheap doesn't seem hard either, so I just might do that at the same time.

Working distance isn't so much of a big deal initially since it'll be an indoor setup for things that won't be moving. Eventually, I want a setup more appropriate for the outside.

But what about lighting? Blowing up something really tiny requires a bit of light, do you guys just use wide open f-stops, longer shutter times, or special flashes or DIY lighting setups?

Thanks.

Alex
08-27-2007, 12:01 PM   #8
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There are several options for this.
I had posted this idea some time ago and it's outlined here on this web site ( a great site to explore I might add) for a DIY ring light. Strobist: Super-Cheap, DIY Ring Flash
You can also use various other lighting setups and just white balance the camera for the type of lighting you use. Just try to make all the light sources the same temperature. Off camera flash with a reflector can work well also. Opening up the lens can help as well but the DOF is so small that you'll most likely want to shoot at f 8-f16 most of the time.

08-27-2007, 05:52 PM   #9
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Peter, I'd like to thank you for starting this topic. I wouldn't mind seeing it made into a sticky.
08-27-2007, 08:50 PM   #10
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Yeah Stu, I'd rather talk about this than a FF 500 MP whatever.
I posted that last response kinda quickly and should expand it a little.

Lets say you want to photograph a small object the size of a house fly that is static. You can get or make a light tent to put the item in and light it from the outside to cast an even light. Generally 2 or 3 lights will fill in all the shadows just fine. You can do the same with regular lamps surrounding the subject and diffused with a cloth in front of each.
An example can be found here on Ebay:
PHOTOGRAPHY STUDIO LIGHT TENT 30W CFL BULB STAND KIT - (eBay item 260152493606 end time Aug-27-07 20:57:09 PDT)

The advantage here is that the lights are on during setup and you can compose, focus and so on with enough light to see everything in the viewfinder.

The type of light used can make a difference as each has it's own temperature that casts a different light colour:
Fluorescent lights are sort of greenish typically but many types are available with colour temperatures of 2200 to 5600 depending on the phosphors and wattage.
Common incandescent lighting is reddish (about 2700
degrees K color temperature).
Quartz halogen lights are also reddish (3200 degrees K). Outdoor light is usually bluish, (about
5400 degrees K) except during sunrise and sunset.

Take an ordinary lamp and add 30-45 watt flourecent CFL or HMI 5500K bulbs. They will give you about the same as your flash and close to outdoor sunlight. Then once you have the setup in place, manually set your white balance on the camera. This will help the image look natural and not washed out.

If you want to just use one light source (sunlight from a window) then use reflectors to circle the subject and fill in the shadows. It's cheap and offers the right colour temperature but you will have less time to work as the sun moves. White cards will do the job just fine. The same can be done with one lamp but still requires white balancing. Here I used the sun on one side behind the camera and a lamp behind the other side of the camera with a reflector behind the subject facing the camera. https://www.pentaxforums.com/gallery/photo-2506.html

White balance instructions are included in the camera manual and each does it a little differently. You can use a white card or 18% grey card that reflects the light you are using. Better yet take a piece of semi transparent white (it must be pure white) plastic, cloth or paper ( a coffee filter does this well) and place it over the lens. Then point the lens into your macro setup with the lights on and set the balance according to the cameras instructions.
If you have a couple of old large filters you can place the coffee filter between them and screw them together creating a white balance filter holder. Just hold it in front of the lens and do your white balance. it's great for other shooting as well. Like inside a church where the light could be coming from natural and man made sources as well as stained glass all at the same time. Everyone will be amazed how your pictures look so natural when all theirs look green or red.

I'm not really addressing ring lights or ring flashes because I can't find a ring flash that works with P-TTL and not sure if there is a version around with enough manual control to work well with a Pentax. Ring lights look like they may do well but I don't own one so can't really comment on how good they are.

I'd like to have others add to this thread if they have suggestions or ideas for this setup.

Last edited by Peter Zack; 08-27-2007 at 09:08 PM.
08-28-2007, 02:17 AM   #11
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You fail to mention the SMC-M 100 mmF4 macro lens.

Although it is manual focus, (but with macto who cares, you focus on what you want anyway) it works very well.

The lens has the ability to extend the elements 50 mm(1/2 life size) without extension tubes, and at 100 mm gives you a little better working distance with the subject.

I actually couple mine to the 1.7x AF TC and get combination of autofocus plus effective focal length of 170 mm.
08-28-2007, 04:59 AM   #12
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QuoteOriginally posted by Lowell Goudge Quote
You fail to mention the SMC-M 100 mmF4 macro lens.

Although it is manual focus, (but with macto who cares, you focus on what you want anyway) it works very well.

The lens has the ability to extend the elements 50 mm(1/2 life size) without extension tubes, and at 100 mm gives you a little better working distance with the subject.

I actually couple mine to the 1.7x AF TC and get combination of auto-focus plus effective focal length of 170 mm.
You're right Lowell, The original question was how to get into macro shooting on the cheap. Starting with a $20 reversing ring and a 50mm lens the discussion developed into how to light and so on.

There was no talk about the numerous "macro" zooms which really are a zoom lens with Close Focus capability since most can't go beyond 1:4 (a few are 1:3) and wouldn't be called a true Macro lens by most people.

There are a number of very good older dedicated macro lenses like the 50 and 100mm M42 screw mounts then the 50 and 100mm K mounts (like yours) and several from 3rd party companies. Right up to today's DA 100 or Sigma 180mm. Then of course the Holy Grail, the SMC Pentax-FA* 200mm F4 Macro ED [IF]. There are tons of choices new and used and even the cheap ones do a very good job.
I used to have the 100mm Phoenix f3.5. Which was an Auto Focus lens and has a dedicated 1:1 diopter lens that you screw on the front for macro shooting. Without the add on lens the 100mm gets down to 1:2. This lens was also sold as a Vivitar and an SMC Pentax version. All of them sell for around $100 on the used market and it's a good performer.

So there's lots of lens choices.
Got a favourite? Add it to the list and maybe show a picture from it.
08-29-2007, 09:15 AM   #13
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Thanks Peter for all your informative answers! I like the light-tent idea.

To come to think of it, I used to know someone who had an extreme macro setup on a Canon and lens-mounted flash, and he used what I think was a piece of paper to diffuse and even out the light (like a tent would) over his subjects out in the field. The guy had some amazing photos. Funny I didn't remember that before.

Alex

Last edited by AlexL; 08-29-2007 at 10:12 AM.
07-28-2008, 12:11 PM   #14
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Sure is useful - thanks!
07-28-2008, 12:12 PM   #15
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QuoteOriginally posted by Mike Cash Quote
The depth of field was so shallow that it was impossible to get the entirety of the tiny crystals all in focus at once. In hindsight, I should have shot it from farther away with a longer lens.
Don't worry Mike, your DoF would have been the same if you kept the same FoV. For a given subject size, DoF is governed by the aperture.
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