Image is always soft using older Sigma Macro on a D5200

[jpine]

Hello All,

I'm really new to DSLR photography and choosing a lens so my apologies in advance. I have a Nikon D5200. I bought an older 90mm Sigma 2.8 macro off eBay for cheap. I can find a model number anywhere on the lens. I will say that it is quite heavy and probably heavier than the my entry level Nikon 55-300 zoom lens. In order to use the lens on my 5200, I have to turn the aperture ring to its highest, which is f20 (going by memory here).

So here is the problem: Every image I shoot is "soft" to the point where it nearly out of focus. I've experimented with different light conditions, as well as different combinations of ISO, shutter speed, and aperture settings. The image is always soft when compared to the same scene/camera settings using the 55-300mm zoom.

Given my limited skill set with a DSLR, I'm thinking I have a bad lens, the wrong lens for the camera, or I simply don't know what I'm doing using an older lens on a newer Nikon camera. Any thoughts?

Thanks!
Jerry

 

[leighonigar]

Could you post an example or two, perhaps with 100% crops of what should be sharpest along with some basic information from the exif (shutter speed, aperture, ISO)? We'll have more ideas then.

 

[Alexander.Of.Oz]

I'd start at the open end of the aperture at f/2.8 and see if I could get my focusing right there. Much more light coming in and easier to see through your viewfinder whether you are in focus or not. Then you have the issue of you moving though, if you are handheld. We can get something razor sharp and then move fractionally and it's nice and mooshy. I've got plenty of shots to prove that!

You could always try using liveview zoomed right in there to focus with. This is only good if you are working from a tripod though. It would be a good test though, to see it in focus really well zoomed in on the rear screen of your 5200 body and then see if it's in focus on import when the camera can't move.

Are you manually focusing? It may be that your eye is not up to manually focusing through a viewfinder, no insult meant by that. Try using the 55-300 manually focusing it also and see if it's a common softness issue.

I'm lucky that I have 20-20 vision still and can use my manual 400mm lens for about 30 minutes before my eye starts getting tired. I give it a rest for 10-15 minutes and I'm good to go for another 30 minutes.

 

[admwright]

In order to use the lens on my 5200, I have to turn the aperture ring to its highest, which is f20 (going by memory here).

Have you heard of diffraction? It is an optical effect you get when using very small apertures, like f20. This shows as a softness in images. First try an aperture slightly down from fully open, say f4-8 and I would try just focusing on something 2-3m from the camera. It should be easier to get in focus. Then you can try getting closer and see how it goes.

 

[leighonigar]

Have you heard of diffraction? It is an optical effect you get when using very small apertures, like f20. This shows as a softness in images. First try an aperture slightly down from fully open, say f4-8 and I would try just focusing on something 2-3m from the camera. It should be easier to get in focus. Then you can try getting closer and see how it goes.

I considered diffraction but on a Nikon camera like the D5200 the aperture is set by the camera and you set (and preferably lock) the aperture at the minimum to allow the camera to do so - if you do not do this the camera will give an error.

UNLESS of course the lens in question is a manual focus lens without any electronic coupling, then you do need to use the aperture ring, and you'll have to guess/use an external meter. I've never seen a manual focus macro lens made by Sigma, but I see loads of the autofocus ones but I guess it's possible.

 

[jpine]

I considered diffraction but on a Nikon camera like the D5200 the aperture is set by the camera and you set (and preferably lock) the aperture at the minimum to allow the camera to do so - if you do not do this the camera will give an error.

UNLESS of course the lens in question is a manual focus lens without any electronic coupling, then you do need to use the aperture ring, and you'll have to guess/use an external meter. I've never seen a manual focus macro lens made by Sigma, but I see loads of the autofocus ones but I guess it's possible.

Leighonigar is correct. I get an error message unless the lens is at minimum setting. This is the lens in question. So what kind of Nikon would this lens work well with? It would be helpful to know since I'm putting it back on eBay. Just too many workarounds with this lens for a novice like me. What I did is take 3 photos of the same object using aperture priority. The images were f/2.8, f/11, and f/22. While there was a difference in the 3 images, the difference was not as much as I expected.

I think I will rent an 85mm Nikon DX macro. If I get better results, I'll pick one up during the post-Christmas clearance sales somewhere.

Thanks all!

JP

 

[MiniD3]

Hi JP,

Very hard to tell sitting on this side of the screen,
the guys are right about diffraction but it should not be that bad with a macro lens,
Quite often, you have to use small apertures with macro just to get the DOF (depth of field) in any case so I don't think this is the main problem

Few things that can cause a problem,
-sometimes you have to "fine tune" the lens focus to the camera, most Nikon SLR's have this option, basically, what is happening the camera focuses either behind the target or in front,
-You are beyond the minimum focusing distance
-The lens is not "communicating" with the camera

There are a few others but thats a start

If you are looking at a new lens for macro, I would not look at anything shorter than 100mm, a 60mm for example, you have to get too close to the subject, and if it is an insect or bug, they quite often fly away before you get the shot

May I suggest
-Nikon 105mm 2.8 macro, (nikon call them micro) or
Join a dedicated Nikon photo forum like Nikonians, all your Nikon questions will be answered in a flash, not to say we are not here, but sometimes other sources will produce more results for a particular product
For example, for Mac related photo issues, this is the best place on the planet!
....Gary

 

[leighonigar]

The compromises doing macro work in using a lens like this are really non-existent. That is assuming the lens is in good condition.
The aperture ring just sits there and you would be manual focusing anyway.

Were you using a solid tripod and working in good light? Was the subject of your tests a small object or a large one? Were you using the green dot for focus confirm? When you get close the depth of field becomes tiny and careful work is required to get what you want within it.

Pretty much all dedicated macro lenses are good. Have you tried this one without the off-brand filter of unknown quality? As I said before it's really hard to accurately diagnose without image samples from the lens in question.

All the cameras with built in autofocus motors will drive this lens - the pro bodies (D1, D2, D3, D4 series); the D100/200/300(s); the D7000, D7100; and the older bodies like the D90, D80, D70 and D50. What won't focus are the D40 type and D5000 types.