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10-30-2008, 04:29 PM   #1
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Macro lens - where am I going wrong?

Hi all,

Am a newbie when it comes to photography and have just recently purchased a macro lens (Sigma 50mm F2.8) to go with my K20D. I have wanted a macro lens for over tens years and decided to take the plunge! Am very excited!

I have been busy taking photos in my garden of various flower and bug shots - however I am disappointed that I am not able to get as close as what I had hoped. How do you create those super close macro shots (like seeing close up bug eyes or caterpillars)? Am I doing something wrong or are macro filters added to the macro lens? Your comments would be greatly appreciated!!
Thanks all,
HeyMissJo

10-30-2008, 04:41 PM   #2
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I think your problem is focal length--your lens isn't quite long enough to catch the little critters without scaring them off first. To get those critters, you're going to need at least a 100mm lens, as not only will it give your twice as much focal length between you and the critters, it's minimum focal distance is longer, as well, thus creating more space between you and your subject. See what I mean:

Sigma 50/2.8--MFD 7.4 in.
Sigma 105/2.8--MFD 12.3 in.

HTH,
Heather
10-30-2008, 04:58 PM   #3
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I hate to say it but Heather is right. I know you probably saved up for quite awhile to get this lens and it is a good one but will be challenging with bugs. Now that being said, you can still get good shots with it.

What you need to do is study your prey. Find out what plants and flowers the insects land on. Once you determine the light direction, set up the camera and tripod on that plant. Use a cable release or a remote to trigger the camera when the subject comes into the shooting location. it takes time but you'll drive yourself mad trying to chase bugs with a macro lens. Sit and wait.
10-30-2008, 06:42 PM   #4
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Maybe trying extension tubes with the 50mm will net better gains though ... but DOF was be thinner than paper I reckon.

10-30-2008, 06:51 PM   #5
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QuoteOriginally posted by heymissjo Quote
I have been busy taking photos in my garden of various flower and bug shots - however I am disappointed that I am not able to get as close as what I had hoped.
Do you mean you've turned the focus ring all the way, moved in until the subejct is in focus, and you're still physically further away from the bugs than you'd like in order to get the closeups you want? If so, you need extension tubes to get even closer.

If, on the other hand, your problem is that you can't even get as close to the bugs as you'd like for logistic reasons - like they fly off - then as others said, you probably should have bought a longer focal macro lens, which would achieve the same magnification at a greater working distance. Right now, you aren't getting the full magnification the lens is capable of if you aren't physically moving in as close as the lens can focus.

QuoteQuote:
How do you create those super close macro shots (like seeing close up bug eyes or caterpillars)?
Most are probably longer focal lengths - to get to 1:1 magnification at a more comfortable working distance - plus extension tubes or the like to get even more magnification (by allowing them to move in even closer).
10-30-2008, 08:03 PM   #6
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In addition to the suggestions already given, Note that there are very few extension tubes available that permit Auto focus and Auto Aperture. The lens you have does not have a manual Aperture setting, so a cheap 'dumb' set of extension tube will not do you much good.

Another choice is a reversing ring and another lens mounted reversed in front of your 50mm. Your Sigma Macro is capable of providing 1:1 magnification, you need greater than that. All of the suggestions will reduce the available light by 1 or more f/stops and as someone has suggested, your DoF will be "thinner than paper" Note the DoF in this photo of a spider that is 2-3 mm


Some other tricks to add to your arsenal:
Spiders - make good macro subjects. Orb weavers like to set there and pose.
For those that don't (Like Jumping Spiders) you can construct an island
with a moat around it. (used for the little girl above)
Cryogenics - 30 minutes in the fridge at 40 F will do wonders to get those little
buggers to slow down long enough for a photo.
And it does not seem to harm them
10-30-2008, 11:11 PM   #7
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Wow - thanks for the super fast responses, much appreciated.

My query was more around magnification of objects rather than how close I can get to them. I completely understand that photographying insects and the like will require a lot of patience. I am finding that when I find the distance where my lens is in focus it is less than 1:1 ratio that the lens is capable of and the object is a lot smaller. Is this because my aperture setting is incorrect?

I am not familar with extension tubes - I take it they are used between the camera body and the lens? Although after reading additional comments above, perhaps these will not suit either.

Perghaps I have yet to see what the lens is capable off..... I suppose I just love those really close up (magnified) shots of insects - a bit like your spider Clee01!
Sorry for the silly questions - have lots of learning to do!!

Am off camping for the weekend - to see what things I can find in the bush.
10-31-2008, 03:23 AM   #8
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There's no doubt that shooting macros takes some time to get used to. These are harder lenses to work with. But once you are comfortable with them the results can be great.

I'd suggest an experiment. Put the camera on a table and turn the focus mode to manual. turn the lens focus out so it's at a full 1:1 magnification. Then move an object closer to the lens until it's in sharp focus. Just leave the camera in one spot. Measure the distance from the front element (glass) so now you know how close to the subject you need to be.

Then open the lens up all the way (f2.8) and take a shot. Progressively close the lens down and take a test shot at each aperture. This will show you how much depth of field each setting gives you with that lens. The test subject should be something with depth (like a coffee mug with print on it) and not something flat.

Most of us will use a macro lens in manual focus mode to get those small subjects in sharpest focus. For my macro setup, I have a set of focus rails and that allows me to mount the camera on a tripod, camera in MF mode and then just move the rails front to back to get the lens in sharp focus on the subject.

Maybe these threads will help:

https://www.pentaxforums.com/forums/pentax-photography-knowledge-base/11161-a...-question.html

10-31-2008, 04:18 AM   #9
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QuoteOriginally posted by Peter Zack Quote
There's no doubt that shooting macros takes some time to get used to. These are harder lenses to work with.
Allow me to amplify that point, if I may.

Before I tried it, I thought that macro photography must be peaceful and serene almost to the point of zen-like meditation. After all, you're just cozying up nice and close to your subject and not doing much.

Then I tried it.

It can be quite intense, absorbing, and frustrating. Especially if you're working handheld, manually focused, and going after anything that moves at all. I don't work up as much of a sweat shooting anything as I do hunched over a flower pot trying to get a killer image of an ant or a bee. When they say "paper thin DOF", they're not exaggerating by much. Sometimes DOF is only a millimeter or two, if you're working toward the extremes of macro. Trying to lay that thin layer exactly where you want it and not move that millimeter or two when you press the shutter is amazingly difficult.

The principles of shooting are the same as for regular photography. Light fall-off still works on the inverse-square law and DOF still depends on aperture and varies according to subject distance. It is just that those effects are more evident over the much shorter shooting distances encountered in macro.

For example, in this shot I did the other day I used an 85mm lens on bellows so that the effective focal length was 150mm. The aperture was set at 5.6 on the lens, but that means an actual aperture diameter of about 15mm, so at 150mm that works out to about f10.



The big leaf in this shot was probably no larger than about 7mm or 8mm across. Notice how at almost 1:1 with an effective aperture of f10 the DOF is probably no more than about 3mm? (And that I assed up where I placed it? I was trying for the near edge of the leaf.)

Very well done macro shots must be very rewarding, I imagine. If I ever take one I'll let you know for sure.

But just keep in mind that it is much harder than it looks. It takes a lot of thought and effort and you can expect a far greater proportion of failed shots than you get on non-macro shots. Don't let it get you down; you're not the only one. That assed-up plant shot was just the least-bad of the dozen or so I took of that single tiny insignificant bit of greenery while lying there on the ground barely moving yet working up a storm for about 15 or 20 minutes.
10-31-2008, 09:03 AM   #10
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QuoteOriginally posted by heymissjo Quote
My query was more around magnification of objects rather than how close I can get to them.
But these are inseparable! Magnification is a function of two things and two things *only*: the focal length of the lens and how close you are. Having a 50mm lens that is a "macro" doesn't magically give it more magnification than an ordinary 50mm lens when shooting at the same distance. The *only* thing that makes it "macro" is that it allows you to focus closer than a non-macro 50mm lens.

So if you want more magnification, you have two choice and two choices *only* - a longer focal length at the same distance, or get closer with the same focal length. Right now, your only option is to get closer, assuming you are not already as close as the lens allows. If you were as close as the lens allows, you're at 1:1.

QuoteQuote:
I am finding that when I find the distance where my lens is in focus it is less than 1:1 ratio that the lens is capable of and the object is a lot smaller.
If it's less that 1:1 (are you sure you aren't?) then you must not have the focus ring turned as far as it can go. I see the lens has a "focus limiter" - perhaps you need to flip a switch to enable you to focus closer?

QuoteQuote:
Is this because my aperture setting is incorrect?
Aperture has nothing to do with it.

QuoteQuote:
I am not familar with extension tubes - I take it they are used between the camera body and the lens?
Yes, and their purpose is to allow you to focus closer, thus getting more magnification. You might also consider a good quality close-up lens to put in *front* of your main lens. Something like the Raynox 150 or 250.
10-31-2008, 09:19 AM   #11
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Your Sigma is capable of delivering 1:1 magnification. That is about as much magnification as you are going to get with any dedicated macro lens regardless of focal length. At that magnification a house fly will fill about 1/3 of the APS-C frame.

If you want more, you will have to go with bellows or extension tubes. With a 50mm lens, you may be able to get 2:1 or even 3:1 depending on extension. Note that depth of field is non-existent at that magnification, that lighting is a bear, and that working distance is also non-existent. Note also that magnification beyond 1:1 is getting into microscope territory.

There is also the option of an auxiliary close-up filter. Many users on this forum have gotten impressive results with the Raynox DCR-250 that may actually be somewhat greater than 1:1 magnification.

Now, regarding some of the incredible pictures you see here...Not all of them are straight, full-frame shots. Many are crops of just the subject that give the impression of greater magnification than was actually present.

Finally...Your Sigma is a fine lens and a great value for the price. I own a copy, have enjoyed using it, and have usually gotten very good to excellent results. Your money was well-spent.

Steve

Last edited by stevebrot; 10-31-2008 at 09:27 AM.
10-31-2008, 09:30 AM   #12
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QuoteOriginally posted by clee01l Quote
...The lens you have does not have a manual Aperture setting, so a cheap 'dumb' set of extension tube will not do you much good...
The Sigma 50/2.8 has an aperture ring in the Pentax mount, so vanilla extension tubes will work.

Steve
10-31-2008, 09:32 AM   #13
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QuoteOriginally posted by clee01l Quote

Out of curiosity, what setup did you use for this shot (aside from the moat)?

Steve
10-31-2008, 09:57 AM   #14
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First make sure the lens is in MANUAL focus. Autofocus is essentially useless for 1:1 macro. Find an object you'd like to photograph. A flower would work (or if you're camping, how about a marshmallow, do you like S'mores?). Turn the focus ring on the lens ALL the way to 1:1 (there should be markings on the lens barrel) Keep getting closer and closer to the marshmallow. Once the marshmallow appears in focus, that's as close as you can get and are at 1:1 magnification.

Again, NOTHING to do with aperture.

QuoteOriginally posted by heymissjo Quote
I am finding that when I find the distance where my lens is in focus it is less than 1:1 ratio that the lens is capable of and the object is a lot smaller. Is this because my aperture setting is incorrect?
10-31-2008, 11:51 AM   #15
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QuoteOriginally posted by Mike Cash Quote
Allow me to amplify that point, if I may.

Before I tried it, I thought that macro photography must be peaceful and serene almost to the point of zen-like meditation. After all, you're just cozying up nice and close to your subject and not doing much.

Then I tried it.

It can be quite intense, absorbing, and frustrating. Especially if you're working handheld, manually focused, and going after anything that moves at all.
Well said, and I totally agree. I'm not that much into macro photography at very close distances, I mainly like the macro ability of my DA35 Limited because the lens doesn't prevent me from focusing as close as I ever need to. My "macro" shots are pretty much all hand-held, and this means I never really get to 1:1 sizes. The shot below (which I also posted in another recent macro thread) is about as close as I normally get.

The problem is that at very close distances any small movements of the camera (whether left/right, up/down, or fore/aft) result in significant changes to the shot. It also means that SR, which compensates for angular but not lateral movement, is kind of useless.

The other big challenge in macro work in the field is wind. I'm sure that at least some of the aches and pains I've acquired over the years have come from being crouched for what seems like ages in an awkward position, gripping the camera and trying to remain as steady as possible while waiting for the d*mned wind to stop blowing my subject around.

But then every once in a while out of many, many shots I get something like the one below and all the frustrations are forgotten (until I see a thread like this!)

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