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| Sigma 150mm F/2.8 OS Macro Lens on a Nikon D800E |
www.dennismook.com
I ordered the Sigma 150mm F/2.8 OS Macro lens Saturday and it arrived last evening. Is this lens a keeper? I don't yet know. There is a procedure I follow each time I buy a new lens to a) make sure it is functioning properly in all respects and, b) it meets my expectations for its intended use.
When I first remove a new piece of gear from its container, I ensure that everything that is supposed to be there actually is. I also read the instructions, even though I think I know how to fully use it, I have surprised myself a few times in discovering that I was under some misconceptions or found some attributes or capabilities of which I was not aware. I recommend, before using any piece of gear, to read the owner's manual. I know that sometimes is very difficult with all the excitement of getting something new, but that philosophy has paid dividends to me.
I then look the lens over carefully, working the focus ring, the aperture lever on the rear, examining the aperture blades for smooth motion and no sign oil. I look closely at the glass inside the lens body, looking for anything that may be in there such as dust, oil, fungus, etc. When all looks well, I then mount the lens on my camera body to test how well it fits. I once had a lens that was actually loose on my camera body! I actuate the shutter at different apertures and look at the mechanism at work and that it repeatedly stops down to the same place each time at each aperture. Additionally, I autofocus and manually focus, testing its consistency and speed.
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| Rose Bushes as a Test Subject from About 8 ft. |
First, I set my camera to aperture priority and make an image of the same subject at every aperture, later looking for any variation of exposure. Second, I autofocus on a subject. I rack the lens all the way out, then autofocus on the subject again, then rack it all the way out, then again autofocus. I do this repeatedly to see if the lens is focusing consistently and properly.
If the lens has image stabilization, I test it on a subject. I shoot with and without it to see how well it works and if it is working properly.
Finally, in this preliminary testing, I shoot a variety of subjects to then just closely examine the images for sharpness across the frame. I once had a lens that was sharp on the left and center, but a bit soft on the right side. One element was not properly cemented in and was out of alignment.
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| Center Crop (1:1) at ISO 400, 1/320th @ F/4 of the above image testing sharpness and IS; the original image is very sharp |
After everything checks out and I'm pretty happy with this preliminary test, I will then calibrate the lens to each of my camera bodies using the FoCal software from Reikan. I have found that this excellent piece of software makes a real difference that you can see on some lenses that may be out of sync with a camera body. The software not only determines if I need to change my micro-focusing adjustment in my camera's menu system, but also gives me which apertures are the highest resolving for this particular lens/camera combination.
To me, it doesn't make much sense to me to have a very high quality camera body and very high quality lenses and NOT ensure that they are matched exactly for the best focus performance. I calibrate all my lenses to each of my camera bodies. It is well worth the effort.
But after all of this, I still haven't decided whether or not to keep the lens. My final test is to take it out several times, look at the images and decide whether or not I am happy with its performance. If I am, I will keep it, no matter what reviewers or others' experience may be. What counts is if I'm happy with a particular piece of equipment for my purposes. If it does not please me, I send it back before the return window closes. More on this later.
Thanks for looking.
Enjoy!
Dennis Mook
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