Tamron 90mm f2.8 focusing problems

[dearlybeloved]

I received a Tamron 90mm f2.8 lens from ebay and I'm using it with a Nikon D300.

its not this one - Tamron 90mm f/2.8 SP AF Di Macro Lens for Nikon AF AF272NII-700

its this one - Recent image by maporms05 on Photobucket

(just wanted to clarify)

I want to take some nice macro shots

like this - http://www.cynical-c.com/archives2/bloggraphics/25738033_16b58d5dc9.jpg

but i cant seem to focus in and get a clean shot.

What am i doing wrong? can anyone give me some advice?

 

[Overread19 7]

You won't get a photo like that with that lens. You'll get close, but not that close with the bare lens.

That said quality macro shots are possible, but try shifting the lens into manual focusing only; af at close distances tends to lack the light and quality to give a reliable AF (some newer cameras from Canon are changing this with macro af modes). With the lens set to manual move the focus to the closest possible point; then move the whole setup (camera and lens) closer to the subject until the part you want in focus is in focus - then gently press the shutter and take the shot.

 

[dearlybeloved]

for some reason, it doesnt seem to let me manual focus. I will toy around with it more and see what I can come up with.

Also, what would a good lens be to look into for the future if I want to upgrade.

Thanks for the info!

 

[Overread19 7]

There should be a switch on the lens to set it to manual focusing - also I think some(all?) nikon bodies also have an af/mf switch on the body that you need to set to mf as well .

 

[dearlybeloved]

I have to slide the barrel down in order to access manual focus. I haven't seen that before so it's good to know. lol.

What would be a better lens to achieve macro shots like the one I posted above?

 

[Derrel]

I own that same,exact model of 90 AF-SP. It won't shoot a fly's eye setup in its stock configuration...you're gonna need a short focal length lens added to the front of the 90. Seriously. Overread can describe the setup for you.

 

[dearlybeloved]

hey derrel, good to hear from you again; its been a few years haha.

Id love to hear about what i can do to achieve that because i was hoping to with this lens. So any ideas on a setup to get the best quality image would be great!

thanks

 

[Overread19 7]

First things first you have to learn how to work with the lens you have before you move up. Increasing the magnification in macro work increases the difficulty at a lot and you want to at least have a solid method before you move up.

The lens you have will get you to 1:1 magnification; that's the same as any other true macro lens on the market of any focal length. There is only one lens in current production (that I know of) which can do more magnification without modification and that is a Canon lens.

To get the best image quality you'll want to have solid lighting, a low ISO, a fast enough shutter speed and a good aperture. Note that chances are for most macro work you'll want a good depth of field so a small aperture like f13-16 would be ideal. You'll also want that low ISO and a good shutter speed. As a result you'll end up needing to use supplemental lighting (ie flash) to boost the light for the shot to get a result - otherwise you'll have to use high ISOs or long shutter speeds (the latter not a possibility if you're hand holding or have a living subject).



From there you can consider increasing the magnification; easy way is to use a reversing ring on the lens. This is a ring which connects two lenses together via their filter screw threads. You'll want a short lens such as a 35mm or f28mm. You'd then mount your 90mm as normal to the camera and then reverse the shorter lens onto the front of it. You will lose infinity focus this way and you'll have to get very very close to the subject to get it in focus.

That said you can boost your magnification a lot like this - the rough math being:
Focal length of the lens on the body - divided by - focal length of the reversed lens = magnification : 1

eg 90mm with a 28mm reversed would be:
90/28 = 3.2:1 magnification which is a massive step up from the 1:1 native of the lens itself.

BUT like I said you won't be able to shoot at 3:1 until you can first shoot clear and sharp at 1:1