Posted by Bruce King on February 20, 2010 at 12:57 PM
The new Sigma 150mm 2.8 Macro arrived last night and of course I had to try it out immediately. I took a couple of staged photos of a tree bud I placed in the center of an african violet. Not great results as you can see, but hey I'd only had the lens an hour or so at this point. I've got a couple questions regarding the lens and the photo which I've included.
First, the instruction sheet that came with the lens says that there is a AF-Manual switch on the body of the lens. Sorry no such switch exists. The instructions go on to say, you can focus manually while still in AF by pressing the shutter release button halfway and turning the focus ring. OK, but definitely not as user friendly as using the switch that unfortunately doesn't exist. I'm also confused about the focus limiter switch. The way I understand it the 3 settings are to be used depending on how far the front of the lens is from the subject. But since one of the settings allows focus from minimum focusing distance to infinity, when would the other two settings be needed?
As for the image, it was taken at the minimum focusing distance of 15", f/4@1.60 sec, ISO 320, no crop and the focus limiter switch set at 15" to infinity. At the other setting that seemed appropriate, 0.38m-0.52m it wouldn't focus. It seems clear that it should. The red bud is slightly smaller than a copper penny. I thought the bud would easily fill the frame with this lens at this distance. I can almost get the same results with my Nikkor 55-200. So I'm a little disappointed in that regard. It appears the only way I'll get extreme close ups is by cropping. I realize I'm just seeing the tip of the iceberg as far as learning to use the lens, but any comments or sggestions are appreciated.
Thanks, Bruce.
Posted by David Bostedo on February 20, 2010 at 1:17 PM
Bruce - That lens has a magnification of 1:1, so it should be able to produce the same sized image inside the camera as the real life object. Depending on your sensor, this may or may not fill the frame, but even on a "full frame" sensor, a penny would fill more of the image than this. I have zero experience in this area though, so hopefully someone else can help.
Posted by Luke Ormand on February 20, 2010 at 1:28 PM
I'll only touch on one of these questions and let more experienced people speak to the others.
In regards to the 3 settings you mentioned allowing different focus settings:
The benefit to adjusting this is it will take less time for you lens to focus if it is set to a shorter distance. If the lens is set to focus from the closest setting to infinity it will take much longer and might not get the focus right. On my Nikon 300 f/4 it has a switch from 3m ~ infinite and minimum ~ infinity. I almost always have it set to the 3m because my subjects are never closer than that
- Luke
Posted by Dan Borzynski on February 20, 2010 at 4:10 PM
If the bud is about the size of a penny, then you should be able to get bigger than than. Not much bigger on a full frame camera, significantly bigger on a cropped body. The penny on a cropped body will not fit in the frame, shot at 1:1 (which is different from full frame).
So what is going wrong?
The first place I would start is to literally photograph a penny. I'm really not trying to be sarcastic here. My best guess is the flower you shot is actually closer to the size of a dime, or even a bit smaller. Once you hit the ballpark of 1:1, objects really are not as big as you would expect them to be,
The second thing I would photograph is a ruler at minimum focusing distance, preferably one with a metric scale. Again, not trying to to be sarcastic here. I want to be sure that you really are at minimum focussing distance. The distance measured should be the same size as the sensor.
The last thing I would suggest is to be sure you really were at 1:1 (minimum focussing distance. Once you get past 1:2, things grow pretty quickly in the viewfinder without you changing your lens to subject distance by all that much. When you are first starting, it is pretty easy to go way under the minimum focussing distance, or not reach it. Eventually, you'll intuitively learn about how far away it is and only have to make small adjustments.
Yeah, things get pretty touchy once you reach 1:1. Don't ask about 4:1
Posted by Gene Lugo on February 20, 2010 at 4:15 PM
Bruce, congratulations on your newest acquisition! It is a fine lens and you will get some pretty incredible images with it - it is critically sharp and it handles beautifully.
I think I can help clear things up a bit. You are correct, the lens does not have an AF/MF switch. You need to control this on the camera. As Luke described, the 3 focus range settings are to limit the amount of rotation on the focus ring from closest focus to infinity. On the one hand, you want a focus ring that has a gradual effect - the 150 has a 270 degree rotation - for precise focusing, but on the other hand, fast focus is a plus in non-macro range, so the compromise is to limit the angle of rotation by limiting the focusing distances. I have successfully used this lens to shoot sporting events (la crosse) and for macro work with insects and flowers.
I suspect that the reason the lens didn't focus at 15" is that you might have measured the focal plane to subject distance, but might have been just inside the 15" limit, which would not have let the lens focus at all.
The way I use mine is to set up the camera AF-On function to only focus when you press the button, and do nothing when you half-press the shutter button. This way you achieve a decent starting point for focus, then you can grab the focus ring and manually fine tune the focus or if you use a focusing rail you can move the camera forward and backward without re-acquiring focus when you press the shutter.
I would not try to grab the focus ring on the lens when the AF is engaged - either by half pressing the shutter or using the AF button. Unlike Nikon's AF-S lenses that are designed to automatically switch over to manual focus the moment you grab the focus ring, the Sigma lenses battle your manual attempts by constantly refocusing the lens. Eventually you will destroy the HSM motor. You will get the first inkling of this when the lens will start to squeal in AF mode when it tries to acquire focus.Don't ask me how I know this. :)
Depending on which camera you use this lens on, the sweet spot for focus with maximum depth of field is either F11 on a D300 where diffraction begins to limit image sharpness, or F16 on a D200. If you want to shoot with minimum depth of field, then don't be afraid to use 2.8 - it is still extremely sharp at that opening.
If I can find one fault with this lens it would be the ability to smoothly render out of focus backgrounds (bokeh). While it is certainly acceptable, there are lenses that do it better. I once read a review somewhere that described the bokeh as "nervous" which would be not as smooth as possible. Smoother is less distracting so it would be more desirable in most circumstances.
Hope you find this information helpful.
Posted by Wayne Jones on February 20, 2010 at 5:44 PM
Bruce,
I see everyone has pretty much answered your questions, so I'll just show you an actual picture of a penny I shot as a test when I got my Sigma 150 a couple of years ago. As you can see, a penny is larger than my APS-C sensor, but the whole thing would probably fit in a 35mm-size sensor. The extremely shallow DOF in macro work takes some getting used to, but you should be happy with this lens. It is super-sharp!
One more note: I was surprised to see that the Nikon version of this lens has no AF/M switch, so I looked at a few Web sites to see what it looks like. Amazingly, half of the Web sites show the lens with the same AF/M switch that my Canon version has, and the other half show the lens you have without that switch. I suspect that some sellers and even lens review sites use the photo of the Canon version to supposedly illustrate the Nikon version of this lens. (For example, compare the photos of this lens on the Adorama vs. B&H Web sites.) If I bought it from a seller that illustrated the wrong lens, I would complain. Anyway, here's the full frame penny on my old 20D.
Posted by Bruce King on February 20, 2010 at 11:39 PM
Thanks everyone for the excellent responses. I'm shooting with a Nikon D5000, so if memory serves me it has a 1.6 crop factor. I took a shot of a ruler as Dan suggested. I then viewed it on the camera's lcd. What showed as an inch on the lcd measured almost exactly an inch, but that one inch increment did not nearly fill the frame. I think that is what you were suggesting? Then I took a photo of a penny. I carefully measured from the front element of the lens to the penny and adjusted so it was maybe 15 1/8th inches at most. As you can see The penny does not nearly fill the frame. I'm perplexed. The penny was shot at f/4. 1/6th sec, ISO 800 but that should be irrevelant to the issue. Apparently I'm missing something.
Posted by Gautam Biswas on February 21, 2010 at 1:00 AM
Bruce,
I am not an expert in macro photography, but have been practising with a 100mm macro lens on my Canon set up. From your last message you mentioned, "I carefully measured from the front element of the lens to the penny...". Normally, the focusing distance for 1:1 is given from subject to the film or sensor plane and not from the front element of the lens. So, in my view you were still further away from the 1:1 focusing distance. The way I go about it is to switch the lens to manual focusing and turn the focus ring to the minimum distance (also the 1:1 size) and then move the camera close to the subject and focusing by adjusting the camera to subject distance. Hope you are soon able to fill the frame with the penny.
Posted by Dan Borzynski on February 21, 2010 at 1:07 PM
Bruce - you did exactly what I was hoping you would do. Here's the problem. The 15" is not the working distance - it is the distance from the recording medium (in this case the sensor) to the subject.
For most lenses and under most shooting conditions, the working distance and the subject to sensor distance is usually close enough to each other in length that it really isn't worth thinkings about being different. In macro, it is a big difference, as you discovered.
This is one reason why, if you plan to do a lot of insect and small animal work, I encourage the use of the longest macro lens you can afford. 15" is a great working distance (lens to subject) but the number manufacturers quote is sensor to subject.
Enjoy the new lens. Once you get used to it, it will open up a lot of photographic possibilities.
Posted by Bruce King on February 21, 2010 at 1:18 PM
Thanks y'all.
After reading Gautam's response a light came on and I had an ah-haa moment. :>)
Makes perfect sense, it just didn't occur to me. I'm putting the lens thru more thorough rigors today. It's bright and sunny out and no flowers blooming yet, but maybe I'll find a few bugs. Nature photography is so cool, and NPN is a great place to learn thanks to its members and all its contributors.
Posted by David Schoen on February 24, 2010 at 9:52 PM
Bruce:
I have a 28 mm Sigma wide angle and it has an AF/MF switch, mainly the focusing ring can be pushed forward or pulled backward. Why don't you try that....
Discussion
10 repliesFirst, the instruction sheet that came with the lens says that there is a AF-Manual switch on the body of the lens. Sorry no such switch exists. The instructions go on to say, you can focus manually while still in AF by pressing the shutter release button halfway and turning the focus ring. OK, but definitely not as user friendly as using the switch that unfortunately doesn't exist. I'm also confused about the focus limiter switch. The way I understand it the 3 settings are to be used depending on how far the front of the lens is from the subject. But since one of the settings allows focus from minimum focusing distance to infinity, when would the other two settings be needed?
As for the image, it was taken at the minimum focusing distance of 15", f/4@1.60 sec, ISO 320, no crop and the focus limiter switch set at 15" to infinity. At the other setting that seemed appropriate, 0.38m-0.52m it wouldn't focus. It seems clear that it should. The red bud is slightly smaller than a copper penny. I thought the bud would easily fill the frame with this lens at this distance. I can almost get the same results with my Nikkor 55-200. So I'm a little disappointed in that regard. It appears the only way I'll get extreme close ups is by cropping. I realize I'm just seeing the tip of the iceberg as far as learning to use the lens, but any comments or sggestions are appreciated.
Thanks, Bruce.
In regards to the 3 settings you mentioned allowing different focus settings:
The benefit to adjusting this is it will take less time for you lens to focus if it is set to a shorter distance. If the lens is set to focus from the closest setting to infinity it will take much longer and might not get the focus right. On my Nikon 300 f/4 it has a switch from 3m ~ infinite and minimum ~ infinity. I almost always have it set to the 3m because my subjects are never closer than that
- Luke
So what is going wrong?
The first place I would start is to literally photograph a penny. I'm really not trying to be sarcastic here. My best guess is the flower you shot is actually closer to the size of a dime, or even a bit smaller. Once you hit the ballpark of 1:1, objects really are not as big as you would expect them to be,
The second thing I would photograph is a ruler at minimum focusing distance, preferably one with a metric scale. Again, not trying to to be sarcastic here. I want to be sure that you really are at minimum focussing distance. The distance measured should be the same size as the sensor.
The last thing I would suggest is to be sure you really were at 1:1 (minimum focussing distance. Once you get past 1:2, things grow pretty quickly in the viewfinder without you changing your lens to subject distance by all that much. When you are first starting, it is pretty easy to go way under the minimum focussing distance, or not reach it. Eventually, you'll intuitively learn about how far away it is and only have to make small adjustments.
Yeah, things get pretty touchy once you reach 1:1. Don't ask about 4:1
I think I can help clear things up a bit. You are correct, the lens does not have an AF/MF switch. You need to control this on the camera. As Luke described, the 3 focus range settings are to limit the amount of rotation on the focus ring from closest focus to infinity. On the one hand, you want a focus ring that has a gradual effect - the 150 has a 270 degree rotation - for precise focusing, but on the other hand, fast focus is a plus in non-macro range, so the compromise is to limit the angle of rotation by limiting the focusing distances. I have successfully used this lens to shoot sporting events (la crosse) and for macro work with insects and flowers.
I suspect that the reason the lens didn't focus at 15" is that you might have measured the focal plane to subject distance, but might have been just inside the 15" limit, which would not have let the lens focus at all.
The way I use mine is to set up the camera AF-On function to only focus when you press the button, and do nothing when you half-press the shutter button. This way you achieve a decent starting point for focus, then you can grab the focus ring and manually fine tune the focus or if you use a focusing rail you can move the camera forward and backward without re-acquiring focus when you press the shutter.
I would not try to grab the focus ring on the lens when the AF is engaged - either by half pressing the shutter or using the AF button. Unlike Nikon's AF-S lenses that are designed to automatically switch over to manual focus the moment you grab the focus ring, the Sigma lenses battle your manual attempts by constantly refocusing the lens. Eventually you will destroy the HSM motor. You will get the first inkling of this when the lens will start to squeal in AF mode when it tries to acquire focus.Don't ask me how I know this. :)
Depending on which camera you use this lens on, the sweet spot for focus with maximum depth of field is either F11 on a D300 where diffraction begins to limit image sharpness, or F16 on a D200. If you want to shoot with minimum depth of field, then don't be afraid to use 2.8 - it is still extremely sharp at that opening.
If I can find one fault with this lens it would be the ability to smoothly render out of focus backgrounds (bokeh). While it is certainly acceptable, there are lenses that do it better. I once read a review somewhere that described the bokeh as "nervous" which would be not as smooth as possible. Smoother is less distracting so it would be more desirable in most circumstances.
Hope you find this information helpful.
I see everyone has pretty much answered your questions, so I'll just show you an actual picture of a penny I shot as a test when I got my Sigma 150 a couple of years ago. As you can see, a penny is larger than my APS-C sensor, but the whole thing would probably fit in a 35mm-size sensor. The extremely shallow DOF in macro work takes some getting used to, but you should be happy with this lens. It is super-sharp!
One more note: I was surprised to see that the Nikon version of this lens has no AF/M switch, so I looked at a few Web sites to see what it looks like. Amazingly, half of the Web sites show the lens with the same AF/M switch that my Canon version has, and the other half show the lens you have without that switch. I suspect that some sellers and even lens review sites use the photo of the Canon version to supposedly illustrate the Nikon version of this lens. (For example, compare the photos of this lens on the Adorama vs. B&H Web sites.) If I bought it from a seller that illustrated the wrong lens, I would complain. Anyway, here's the full frame penny on my old 20D.
I am not an expert in macro photography, but have been practising with a 100mm macro lens on my Canon set up. From your last message you mentioned, "I carefully measured from the front element of the lens to the penny...". Normally, the focusing distance for 1:1 is given from subject to the film or sensor plane and not from the front element of the lens. So, in my view you were still further away from the 1:1 focusing distance. The way I go about it is to switch the lens to manual focusing and turn the focus ring to the minimum distance (also the 1:1 size) and then move the camera close to the subject and focusing by adjusting the camera to subject distance. Hope you are soon able to fill the frame with the penny.
For most lenses and under most shooting conditions, the working distance and the subject to sensor distance is usually close enough to each other in length that it really isn't worth thinkings about being different. In macro, it is a big difference, as you discovered.
This is one reason why, if you plan to do a lot of insect and small animal work, I encourage the use of the longest macro lens you can afford. 15" is a great working distance (lens to subject) but the number manufacturers quote is sensor to subject.
Enjoy the new lens. Once you get used to it, it will open up a lot of photographic possibilities.
After reading Gautam's response a light came on and I had an ah-haa moment. :>)
Makes perfect sense, it just didn't occur to me. I'm putting the lens thru more thorough rigors today. It's bright and sunny out and no flowers blooming yet, but maybe I'll find a few bugs. Nature photography is so cool, and NPN is a great place to learn thanks to its members and all its contributors.
I have a 28 mm Sigma wide angle and it has an AF/MF switch, mainly the focusing ring can be pushed forward or pulled backward. Why don't you try that....