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06-12-2012, 12:11 PM   #1
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Would a real macro lens improve much on what I have?

At least one that costs less than my truck?

http://farm9.staticflickr.com/8145/7180886353_a91f910c7f_k.jpg
this is the direct JPEG from my K20D using my A35-105 F3.5 without editing (unless flickr messed with the size)

edit: apparently flickr completely resized the image since the original flower is much bigger but no site i have found supports the full 100% image size. going to get a better crop and post it here.

It was done handheld with the shake reduction turned on and set to more than likely the wrong focal length, so I could get the image a bit more crisp for focus if I really tried. The main thing is the purple flower in the middle is about the size of a US quarter if you squash it, how fancy a macro setup would a person need to do better than that, could it be done with one lens or would it take stacking of random things? I see pictures that practically show the stuff caught between a fleas teeth that I read use all manner of stacked and reversed contraptions, and I also see that my most loved Pentax A series has a few genuine macro lenses in it though most are WAY out of my price range when they can even be found.

I think I may have used the 105mm end of the lens for that shot since I was going for better depth of field so it was something like 24 inches away (I forget) rather than the 35mm end which can focus on something 5 inches away.
This lens has a bizarre shift in the focus ring that makes it a macro lens for the whole 35-105mm range for those that don't know. I think if more people had a clue what this lens does I would have had to pay more for this minty replacement copy for my old one.

I don't trust anything on the lens review here since I just proved to myself that whoever put the minimum focus distance at 150cm clearly meant the minimum focus distance at 105mm without using the macro and didn't specify that.

Also I want to be able to use the cameras front and rear dials in M mode and also have the option of A mode, so if the pile of stackage makes it read like an M lens to the camera then it doesn't help me at all, bugs don't really care to sit still while you monkey with stuff.



Last edited by PPPPPP42; 06-12-2012 at 12:24 PM.
06-12-2012, 12:20 PM   #2
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If you want to use both dials you need to use auto aperture on the lens, so with the A35-105 set the aperture to A, that should do it.

About if macro lens will improve this shot, my answer will be no but Macro lenses do give you more options in ways to approach flower photography.
I've seen the DA35mm limited being used very successfully for these kind of photos and the price is decent for this lens.
PENTAX : Select a PENTAX interchangeable lens camera or a lens model

https://www.pentaxforums.com/forums/lens-sample-photo-archive/153168-pentax-d...o-samples.html


Have you ever tried to use the A 50mm for these kind of photos, it might work really well.

For cheap and cheerful there is also DA35 f/2.4 which seems to be able to focus decently close.
http://www.pentaxphotogallery.com/photos/gallery/query?camera=&lens=4000

Last edited by Anvh; 06-12-2012 at 12:27 PM.
06-12-2012, 12:25 PM   #3
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Ok fixed the original post and that flower is also about the size of a US quarter.
And yes I use this lens only in A and control with the dials, but I just wanted to mention that since most of the custom setups kill the cameras ability to talk to the lens which wouldn't work for me.
06-12-2012, 12:31 PM   #4
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Well, it isn't a true macro lens. It only reaches 1:4 at its best, so your options are limited by that unless you add extension or something. I think you would notice a difference in sharpness and overall IQ with a good macro lens, but probably not vastly different. One would allow you to get to 1:1 without hassle though.

The flower in the center of your pic would about fill the entire frame at 1:1 if it's about the size of a quarter.

Another edit: Looking at the crop you updated your post with, yes there is a huge difference between what a true macro lens can do, and what you're getting here.

06-12-2012, 01:07 PM   #5
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Yes it can make a huge difference. I have a Pentax DFA 100mm Macro and I can tell you it does. If you really love macros go for it. It will be a lens you'll use a lot and it will pay for itself in no time. Check the lens samples on this forum for the macro lens to get a feel of what they offer.

Oh yeah, I'm finding everyday new uses for my macro lens besides macro. Portraits, landscapes, and other shots I never though I would use it for.
06-12-2012, 01:09 PM   #6
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See https://www.pentaxforums.com/forums/pentax-lens-articles/152336-cheap-macro-b...lose-work.html

Definitions:

* Magnification happens before you snap the shutter.
* Enlargement happens after you snap the shutter.
* Depending on who defines what, 'macro' means magnification of 1:2 (half life-size) or more, like 1:1 or 2:1 or 10:1. Some insist the cutoff is 1:1, which means that if an object is 10mm high in the real world, it is also 10mm high on the camera frame.
* Many lensmakers label their close-focus lenses, which may only reach 1:4, as 'macro', maybe because it takes less ink and is sexier than "close-focus".
* With vanishingly few exceptions, any zoom marked 'macro', isn't.

So MACRO just means that we're shooting close, with (half) life-size (or greater) images. MACRO LENS has another implication: edge-to-edge flatfield sharpness. With the same vanishingly few exceptions, "macro zooms" don't qualify. Enlarger lenses (ELs) DO qualify. That's why much of my macro shooting is with ELs on extension (bellows or helicoid and/or tubes).

Will a 'real' macro lens improve your shots? Maybe, maybe not. See the article linked above on how to shoot great macro without a 'real' macro lens. IMHO the main benefit of such a lens is convenience. It will shoot well close-up and also at a distance (maybe), so it can be used for general photography. (Some macro lenses are optimized for close work and don't do well at infinity.) If you have a budget for such a lens, get it. If you're a cheap bastard like me, see the article.
06-12-2012, 01:27 PM   #7
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QuoteOriginally posted by PPPPPP42 Quote
Ok fixed the original post and that flower is also about the size of a US quarter.
And yes I use this lens only in A and control with the dials, but I just wanted to mention that since most of the custom setups kill the cameras ability to talk to the lens which wouldn't work for me.
Thought i was missing something

Lens advice keeps standing though but yes a macro lens will "help" to improve that but you need to use better technique as well though, after all you're taking the photo not the lens.
06-12-2012, 01:41 PM   #8
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How is that 1:1 or 1:4 ratio calculated and is it the same for all focal lengths if its a zoom?

If I understand correctly (from wikipedia) its the ratio of the size of the original object to the size of the image of it the lens shines on the sensor?

So If I make the original image on my computer the exact same size as the sensor in my K20D then a picture from a 1:1 ratio lens would be life size?

EDIT: my technique on these was extra sloppy because I was in a hurry and not really making a serious attempt for the example, there is wind blowing and it was all just crouching down hand held in front of a flower pot.

2nd edit: actually I can't find any way that this could be calculated as a 1:4 lens looking at the pics, the one in thread is a crop of the actual image without resizing, and when I shrunk the uncropped original to the size of a K20D sensor the flower was just a tiny spot not even 1/4 of its original size.


Last edited by PPPPPP42; 06-12-2012 at 01:49 PM.
06-12-2012, 01:52 PM   #9
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QuoteOriginally posted by PPPPPP42 Quote
If I understand correctly (from wikipedia) its the ratio of the size of the original object to the size of the image of it the lens shines on the sensor?
This is correct. At 1:1 you'll be able to capture about 24mm across the frame, the exact dimensions matching the size of your sensor. At 1:4 you'll be able to capture approximately 96mm across. Magnification is independent of focal length. Whether your zoom lens can attain 1:4 across its range of focal lengths depends on its design. I'm not sure if that particular lens can or not.

With 1:1 macro lenses, the focal length affects working distance. A 105mm or 150mm focal length will let you focus at 1:1 from farther away than a 50mm or 35mm lens. For bugs and such, the farther away you can be, the better.

QuoteOriginally posted by PPPPPP42 Quote
2nd edit: actually I can't find any way that this could be calculated as a 1:4 lens looking at the pics, the one in thread is a crop of the actual image without resizing, and when I shrunk the uncropped original to the size of a K20D sensor the flower was just a tiny spot not even 1/4 of its original size.
The shot above is not 1:4 magnification. If the flowers are each the size of a quarter, a 1:4 shot would likely show just a couple of flowers. You can figure out how much of the scene you'd get by taking a ruler and looking at how much of the plant fits within ~10cm.
06-12-2012, 02:02 PM   #10
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QuoteOriginally posted by PPPPPP42 Quote
How is that 1:1 or 1:4 ratio calculated and is it the same for all focal lengths if its a zoom?
Magnification is the ratio of the subject's size on the sensor to its life size. If a 20mm subject is 10mm on the sensor, it's 10:20 or 1:2 or 0.5x, half life-size.

Focal length matters in two ways:

1) Working distance. A lens reaches its greatest magnification when the focus distance equals the focal length, and no non-reversed lens can focus closer than its focal length. So a 50mm lens lets you work close, at up to 5cm / 50mm / 2in; a 100mm lens allows (or forces) you to work twice as far.

2) Calculating magnification from focal length and distance: M = F/(D-F) where M is magnification, F is lens focal length, and D is subject-lens distance.

QuoteQuote:
If I under stand correctly its the ratio of the size of the original object to the size of the image of it the lens shines on the sensor?
Just the other way around. A 15mm subject that is 5mm on the sensor is 5:15 or 1:3, 1/3 life-size magnification. A 5mm subject that's 15mm on the sensor is 15:5 or 3:1 or 3x.

QuoteQuote:
So If I make the original image on my computer the exact same size as the sensor in my K20D then a picture from a 1:1 ratio lens would be life size?
Not exactly. What you see on a computer screen is an enlargement. Your camera sensor is roughly 24x16mm. (Nominal APS-C is 25.1x16.7mm. My K20D sensor is 23.4x15.6mm.) If you shoot something that's 6mm tall, and its captured image on the sensor is also 6mm tall, then you're at 1:1 or 1x magnification. If the captured image is 12mm tall, you're at 2:1 or 2x. If the captured image is only 3mm tall, you're at 1:2 or 0.5x. What you see on the computer screen is probably a huge enlargement, because "life-size" is pretty damn small.

Confused yet? Good. All this is a little tough to wrap one's head around. I still trip over it, and I started with macro many decades ago. Ay yi yi.

Last edited by RioRico; 06-12-2012 at 02:07 PM.
06-12-2012, 02:10 PM   #11
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Better lenses never hurt, but maybe you also want to have a look at your stuff and ask yourself what you actually really need to improve on for the biggest 'gain'. That maybe all sorts of things - your eye, lighting, composition, colour, subject. A lot of that you fix by analysing what works and what doesn't. A new lens rarely fixes those.
06-12-2012, 02:11 PM   #12
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QuoteOriginally posted by Philoslothical Quote
QuoteOriginally posted by PPPPPP42:
If I understand correctly (from wikipedia) its the ratio of the size of the original object to the size of the image of it the lens shines on the sensor?
This is correct. At 1:1 you'll be able to capture about 24mm across the frame, the exact dimensions matching the size of your sensor. At 1:4 you'll be able to capture approximately 96mm across. Magnification is independent of focal length. Whether your zoom lens can attain 1:4 across its range of focal lengths depends on its design.
Magnification is "the ratio of the size of the original object to the size of the image of it the lens shines on the sensor". No, just the other way around. If a 40mm object is 10mm on the sensor, it's 1:4, not 4:1.

"Magnification is independent of focal length." No; magnification if a function of focal length and distance.

Last edited by RioRico; 06-12-2012 at 02:22 PM.
06-12-2012, 02:23 PM   #13
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QuoteOriginally posted by RioRico Quote
No, just the other way around. If a 40mm object is 10mm on the sensor, it's 1:4, not 4:1.
You're right, that was reversed.

QuoteOriginally posted by RioRico Quote
No; magnification if a function of focal length and distance.
A given magnification (e.g. 1:1) gives the same result regardless of focal length. That's what I think he was asking. I also explained the relationship of working distance to focal length.
06-12-2012, 02:31 PM   #14
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I have the A 35-105 & it's a great lens, but for closeup shots, a good macro lens is a huge improvement. I happened across this Promaster 100mm macro lens for sale for $60 on the forum, and it's absolutely terrific. It's a true 1:1 macro lens. It's tack sharp, has great color, and it has the "A" setting. There's nothing I don't like about this lens. I heartily recommend it.

On the very rare occasion that I want to get even closer, I have a cheap eBay lens reversal adapter that allows you to reverse a lens on the front of the macro lens for greater magnification. I use a 50mm prime for that purpose & I can get extremely close, but that makes it a challenge to focus handheld at that high magnification.

RioRico's macro guide is superb, by the way. Tons of great info in there. Definitely worth a read.

Cheers & have fun,
Bobbo :-)
06-12-2012, 02:36 PM   #15
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Before you spring for a true macro lens have a look into "plus" close up lenses. These screw into the filter threads and let you focus much closer. Extension tubes, which fit between the body and the lens but have no optics, are another way. They do avoid any optical degradation from the plus lenses, but ... they increase exposure. This is compensated for by the TTL metering. However, automatic tubes enabling auto diaphragm operation (and you don't want to go any other way!) aren't cheap and seem hard to find. Automatic tubes retaining auto focus? I have no idea if they're available.

Generally speaking a tripod is almost a necessity for high quality close up or macro work, as is a lot of patience, even for flowers. The wind is your enemy!


My personal opinion is that auto focus is probably unnecessary for closeup/macro work. Generally there's no great hurry, so manual focussing is fine. A focus rail is a real help, allowing tiny adjustment fore and aft, and right and left, without uprooting the whole tripod camera shebang.

If you can find one Vivitar makes/made a very respectable macro lens, 100mm, f3.5. I have the manual focus edition, I think there's an autofocus version. BTW, the Promaster that GibbyTheMole mentions looks exactly like the Vivitar, which also has a Cosina incarnation. There is a Flickr group devoted to this little gem of a lens. It ain't pretty, but it does the job.
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