Gotta a new macro lens and Im having trouble

[10" Red Devil]

Yeah I know beerguy, big suprise right?

I cant seem to get all of the picture I want in focus, I seem to get only the center in focus. Moving away from the subject helps, quite a bit but there is still quite a bit of blurring on the edges.

The lens Im using is a sigma 105mm EX 2.8 that does 1:1

Anyway I am a complete noob so any advice would be most welcome.

 

[steve68]

i was told by a friend that with a 105mm u are going to have to be a bit back in front of the tank & if u want to zoom in on the ones in the back u will have to be up to the glass, also try using it in manual mode with auto focus it works much better.
im buying a 105mm my self but i dont have the cash yet

 

[gregr]

Depth of field is what you need to increase to get more of the picture in focus and that requires smaller apertures. Give this article a read- it will help you understand how the camera/lens works and what you need to do to get more depth of field.
Holler if you have questions

 

[APFparadise]

I find blurring the right amount a great thing in bringing items into focus. DOF control is something you learn with practice. One thing to consider is your lense's minimum shooting distance, too. Come too close and you can't get anything in focus. You can decrease the distance quite a bit by going to manual focus.

 

[BlueCorn]

Also, when shooting with large apertures you need to compose the picture more carefully. It's important to keep the items that you want in focus on the same plane.

 

[10" Red Devil]

Thanks a lot guys!

 

[Fountainhead]

In addition to using a smaller aperture for greater depth of field, I find using a lens like this absolutely requires the use of a tripod. Also, you didn't mention your camera body (in this thread anyway) but check to see if it has DOF preview button so you can preview exactly what will and won't be in focus.

 

[10" Red Devil]

Its the Pentax IST DL.

 

[astrogazer]

The Sigma 105 is a sharp lens, but I agree with all of the above. Depth of Field id minimal at 1:1, 1/4" or less unless you really stop down. Tripod mount and slow the exposure. Show us what you get.

 

[gregr]

With some subjects a flash will help a lot. Acros, some zoos and some other corals turn funny colors if you use a flash but the Porcelain Crab for instance- a flash will add light that will allow you to use faster shutter speeds... which will allow you to get decent depth of field on moving subjects (without raising the iso).
This was shot with flash at night when the tank lights were off:

That was a pretty small crab and fish- maybe not quite 1:1 but still pretty close.

 

[10" Red Devil]

Well I think Im going to move to a Nikon D50.

Found out it really wasnt a good idea to buy a floor model. I guess they have delicate sensors which people really mess with unless they are behind a cage.

The place I bought it at does not have any new IST DLs so I may just get the Nikon. Sucks because I will then have to return the sigma for a nikon model.

But I guess my goof for not researching it better. I will get you guys some pics when I get the new camera.

 

[astrogazer]

IMHO the Nikon is much more camera, you'll love it.

 

[HotHotHot]

gregr,

That is one GREAT crab pic!

I gotta get me a macro lens.

Ed

 

[steve68]

Nikon is an awesome camera, i have had mine for a week & i cant wait to get a macro lens.

 

[10" Red Devil]

<a href=showthread.php?s=&postid=8110631#post8110631 target=_blank>Originally posted</a> by astrogazer
IMHO the Nikon is much more camera, you'll love it.

Yeah well my point and shoot is a old nikon 2500 and it definitely outperforms the pentax in the white balance area. It white balances perfectly resulting in color that is exactly what I see and amazing, whereas the pentax is off quite a bit and no matter how much I fiddle with the custom white balance and my kalk lid I cant get it to balance. So colors come out duller then they actually appear for me. Of course this could be operator error. But then again I could always get the cheapy 2mp nikon to white balance.

 

[10" Red Devil]

This also means I will have to give up the Sigma lens I purchased.

So should I just get the same lens nikon mount compatible replacement?

Thanks.

 

[astrogazer]

Trade it back out for the Nikon mount, that's one of the lenses I have and I really like it.

 

[louist]

quite a bit but there is still quite a bit of blurring on the edges.

Try to keep the front of the lens parallel to the glass of your aquarium. Shooting at an angle to the glass often results in what you are experiencing.

 

[10" Red Devil]

Okay so we now have a Nikon D50 but I will have to see if I can exchange the Sigma pentax mount for the nikon one. Bought it from www.KEH.com so well see.

Thanks for everyones help!