Sigma 150mm f/2.8 HSM macro...

[barfastic]

hey guys,

i have a few questions regarding this lens (which i so happened to purchase today).

First off, i am in love with its black matt/sparkle finish... its so beautiful!

but i come here to ask for some advice, ive read around on some other blogs/forums that while it is a constant f/2.8 (DOF-wise) light wise its not... dont know if that makes sense.

ok... heres an example...

Im in manual mode. when im zoomed to infinity i can get aperture of 2.8, but the closer i get to my subject the aperture increases. Thus making the picture darker.
when im focused in to its closest focusing range, the minimum aperture i can get is f/5.6.

i read that its normal on some forums, and that the depth of field does not change, it just limits the amount of light that it lets in.

then the other forums went on to explain this or something ( i got sorta lost). But what they finally went on tos ay is that it occurs on msot macro lenses, and tis jsut that nikon shows teh actual effective aperture while other camera brands show what is selected...

the more i look into it, the more confused i get...

can anyone help me understand this?

thanks in advance,

tomorrow i get my flash, so its time for some macro work before i get drafted

 

[Derrel]

The behavior exhibited by your Sigma 150 f/2.8 is perfectly normal. I have a Tamron 90mm f/2.8 macro and a Nikon 60mm f/2.8 macro lens; when either one is extended and focused at 1:1 (life-size) magnification the maximum aperture drops to f/5.6.

This behavior of a lens losing effective aperture value has been around for a long,long time. With a view camera, one can extend the bellows longer and longer, in order to focus a lens closer and closer, and this loss of effective aperture was called bellows factor. We used to have to compute bellows factor manually, with the formula of image size divided by object size, squared, and then take that factor and multiply it by the ASA of the film in use. Meaning focusing on a steel ruler and literally physically measuring the image size on the ground glass,and then doing the math, and re-setting the new ASA/ISO value into the light meter, and then metering the scene with the new, lower ASA/ISO value keyed into the light meter.

So, don't worry. This loss of effective maximum aperture as the lens moves into the close-up focusing range is natural and expected. If you are focusing very close, you *will* lose aperture value if you use only the lens to focus.[I am excluding using a + diopter filter to prevent some semantic smart-a$$ from suggesting a way around losing aperture value by using a + diopter like a Canon 500D to circumvent the loss of effective aperture.]

When somebody is discussing a Nikon macro lens not showing the effective aperture, that is referring to a manual-focusing macro lens or a non-coupled macro lens that is not supplying up to the second data via a CPU in the lens. With lenses and accessories that do not have CPUs in them, professional Nikons allow the user to manually input the lens focal length and maximum aperture value into the camera, so with a 30-year old Micro-Nikkor, if I input 105mm and f/2.8, the max aperture will be f/2.8 at "normal" focusing distances, but as soon as a lens is focused fairly close, the maximum aperture loses *effective* aperture,and starts to dip...f/3.2, then f/3.5, the f/4, then f/4.5, and so on. But without a CPU to communicate to the meter, the camera will "report and record" in the EXIF information only the physical location the aperture ring was at at the moment of exposure.

With through the lens light metering, this loss of effective aperture is compensated for by the camera's metering of both daylight and electronic flash lighting, but you do need to recognize the loss of aperture when trying to do really precise match-ups of say flash on a butterfly at 18 inches and the background! Radical changes in focusing distance can cause the effective aperture to vary by as much as two full f/stops, so be aware of that if you are working in fully manual or semi-manual exposure metering modes.

There is a huge misunderstanding about depth of field,and juts a few days ago I was reading a discussion on Nikongear.com between Ikkilia-Nillsa and another photographer, comparing differences in depth of field between the manual focusing, NON-CPU-equipped Zeiss 100mm f/2 macro and the Nikon 105mm f/2.8 AF-S VR-G Micro~Nikkor lens; perhaps you read that discussion, or another. Regardless, the depth of field will be the depth of field for the **effective** aperture that is in use. With the lens wide-open at f/2.8, when you focus down to 1:1 or maximum close focusing, the depth of field will be the depth of field you obtain at an effective aperture of f/5.6. If you want the depth of field of f/11, you will need to set the lens aperture to f/11 using the aperture control. What is odd about really close-up photograhy is that the depth of field you get is determined almost entirely by the magnification ratio, and not by lens focal length. In the 1:1 to 1:4 ranges, my experience is that depth of field is virtually identical between the 60mm Micro-Nikkor and the 180mm f/3.5 Sigma, given the same image magnification; so, filling the frame with a small object 25 millimeters tall, the 60mm lens at 3 inches and the 180mm lens at 9 inches away produced the same image size, and the same depth of field when used at the same effective aperture values.

if this is too much information, just go back to the title: don't worry, be happy! The Sigma 150mm is a beautiful, beautiful imager; it has nice bokeh and a wonderful drawing style. I think the pictures I have seen from the Sigma 150 macro are some of the prettiest macro and close-up images i have seen from any macro lens. If I didn't have their 180, I would probably be interested in the 150.

 

[Markw]

If you didnt have their 180, which would you chose and why? I am thinking about getting one of them soon and its a hard choice. Great post!

Mark

 

[Derrel]

I think if I did not have a long tele-macro lens, I might buy the Tamron 180mm f/3.5 because, based on photos that I have seen, I think it has the prettier bokeh between the Sigma and Tamron 180mm lenses.

The Sigma 150mm looks quite good too, bokeh wise. In my own personal experience, Tamron seems to be the best-made, best-performing of the 3rd party lenses I have owned, which have been Sigma, Tamron, and Tokina.
I have had five Sigmas in Nikon mount and one in Canon mount, and all of them except the Canon-mount ones have come with at least "some" issues, including my 180 Macro's erratic AF behavior; I have owned two Tokinas and both were apparently made in a heavy-duty style,but both Tokinas were optically sub-par and one fell apart. I have owned three Tamron SP or Superior Performance lenses over a span of a little over 20 years; a 300/2.8 SP-LD in the eighties, and a 90 AF-SP macro,and a 17-35 Di,and all have worked flawlessly.

If I shot Canon more, I think Sigma might work better, based on the rather long continuous use of a similar AF system in the 20-30-40-50D Canon bodies,and the all-electronic, non-mechanical diaphragm system Canon uses. I think it might be easier for Siggy to make lenses in Canon mount than in Nikon's mount.

 

[bagpuss]

Hi everyone,
I'm a " newb" and would like to ask: Got a Canon 500D only with kitlens ( IS ). Also still have Sigma 105mm DG macro EX from my old Minolta Dynax . Now -- I'm trying to figure out how I could use it on my new cam. !! But the more I google , the more I get confused with all those adapters and mounts !!! Its so frustrating ... PLEASE HELP SOMEONE

 

[Montana]

I think it might be easier for Siggy to make lenses in Canon mount than in Nikon's mount.

In my experience (both personal and research) this is backwards. Sigma tends to nail down Nikons system way better than the Canon mount. Check out Sigma's 50 f/1.4 fiasco in canon mount. Crapshoot to say the least. I own 2 sigma lenses, and lets just say that I won't be buying anymore in the near future. And now there are reports of some of the "newer" Sigma lenses not working on the 7D, but its not across the board. meaning one guys lens might work, and the next guys sigma made one month later doesn't.

To the OP, I am not in any way implying that you bought a "dud". in fact, there are many things I do happen to like about Sigma lenses. The build is decent, the EX line build is great. The finish on mine has held up tremendously, the hoods are some of the best out there in my opinion, and they are free with the lens.

 

[Overread]

If you didnt have their 180, which would you chose and why? I am thinking about getting one of them soon and its a hard choice. Great post!

Mark

The way I have always seen it argued and the way I chose my 150mm macro over the 180mm sigma was that the 180mm is more suited toward a macro shooter who does more tripod based macro; whilst the 150mm is more suited for those who do more handheld macro.
Tamron vs sigma I have no idea about, but from what I have seen the Tamron appears to be a good solid macro lens, but for some reason the Tamron 180mm is just not as popular as the Sigma 180mm macro.

As for sigma build quality and canon compatability I suspect the problems with the 7D are relaited to the fact that Sigma have to back engeneer the design of canon mounts and electrical interfaces - canon don't release this info to other manufacturers. This means Canon can make little changes to things that won't affect their own gear, but will affect some 3rdparty gear - a good example is that a lot of older sigma gear needs to be rechipped to work on modern digital cameras.
Sadly I do feel that sigma have some problems with quality control (especaily on their superzoom lenses) which gives them a rather negative light on the internet. However I hasten to add that even canon has a poor track record for their own superzoom - 100-400mm - though things have improved these days its still very hard to make superzoom lenses in batches and have every one come off as it should.

Overall I have two sigma macro lenses (70mm and 150mm) and would have no problem adding a good lens like the 10-20mm (new or old) to my setup - but it is always best to treat things on a lens by lens basis rather than aiming for a single coverall for every product sigma make

 

[Derrel]

Well, Sigma has had ample problems with Nikon's mount as well; when the Nikon D200 came out, there was a major issue with compatibility. As overread mentioned, Sigma does have to reverse-engineer their lenses to the camera makers' cameras, and the camera makers' offerings are not static. A case in point--with the D200 and D2x, Nikon introduced a 4-mode AF system. Canon added an AF-ON button to its non-pro cameras for back button focus, instead of the * button; when the camera makers add a major, new, different body control and/or an entirely new AF sub-routine, Sigma's HSM autofocus protocol suddenly is "broken" compared to Nikon's Autofocus Silent-Wave or Canon's USM protocol, and the camera manufacturers are not required, and they DO NOT keep Sigma informed on their adjustments, features, updates, and changes. No major company gives its direct competitors full information, unless they have a working technology sharing agreement, and Sigma and Canon and Nikon most emphatically do NOT have any sharing agreement. Sigma is a sales-stealer from Canon and Nikon. When Canon or Nikon make an improvement to their offerings, Sigma does what it needs to do, which is to offer re-chipping.

As to the Sigma 180 macro--I use mine hand-held most of the time, with flash. It's not that heavy,and on a big camera it balances nicely. It has a tripod collar, which is handy for quick changes from horiz. to vert..

 

[w4llet]

Derrel, you gave a nice explanation about behavior of a lens losing effective aperture value when shooting 1:1. You really are an expert and put words in a simple way to understant that behavior. Congrats!

I´ve read several users on Flickr telling that is a "deffective lens" and they try go to change the lens at the store.... Nonsense!

I will also recommend people to read this link about that behavior:

Macro Camera Lenses

I bought this sigma 150mm 2.8/APO macro two days ago, and I am amazed by picture quality... Nikkor user talking here. I did some initial test shots at night, hendhelded and using a sb600 flash. I loved the results as you can see in theses links:

new macro toy on Flickr - Photo Sharing!

Cactus III on Flickr - Photo Sharing!

Cactus II on Flickr - Photo Sharing!


I also used as a short telephoto, nice results too:

lake duck on Flickr - Photo Sharing!


By the way Derrel, do you know anything about lighmeters operation?

Thanks,

W4llet, from Brazil.

 

[xjrrrdx]

I have this in the canon version. Maybe I am behind the curve and misread, but if I am on 2.8 no matter what it always stays at 2.8.

 

[Overread]

Its a difference in how canon and nikon camera bodies meter and read details from the lens. At the end of the day modern macro lenses all end up reducing their apertures as they approach the 1:1 magnifiaction ratio - in canon camera bodies this is not reported to the photographer through the camera and the lens stays as an f2.8 - Nikon users on the other hand do get this effective aperture report and the lens will start to close down, even though its still wide open.

This really only affects the apertures you see on the screen, the actual amount of light entering the camera is still the same and the meters will still give you the correct shutter speeds based on aperture and ISO settings.

 

[D-B-J]

Its a difference in how canon and nikon camera bodies meter and read details from the lens. At the end of the day modern macro lenses all end up reducing their apertures as they approach the 1:1 magnifiaction ratio - in canon camera bodies this is not reported to the photographer through the camera and the lens stays as an f2.8 - Nikon users on the other hand do get this effective aperture report and the lens will start to close down, even though its still wide open.

This really only affects the apertures you see on the screen, the actual amount of light entering the camera is still the same and the meters will still give you the correct shutter speeds based on aperture and ISO settings.

Wait, so my 105mm micro stays at 2.8 at a 1:1 magnification, even though the camera reads it as 5.6? (its on a d200)

 

[Overread]

Kinda sorta - the aperture blades themselves have not moved, but by design the lens has closed down to f5.6 - this is the same for the canon lens, just that on canon the effective aperture change isn't reported - it just sticks to the status of the aperture blades.