Macro focusing

[SkyPapa]

I've been trying to get a good image of my corals for a while and I still have trouble nailing the focus.

These are with my D300s and and Nikon f2.8 105mm micro on a gitzo tripod and mc-30 wired remote.
I was shooting at f25 and slow shutter speeds, manual focus, iso auto and some ev comp.
I wear reading glasses but have the diopter set and don't use them for focusing. The focus indicator is lit when the trigger is pulled.
These are the best of a lot.

Any suggestions.

 

[BlueCorn]

For starters, I try never to go above f/16. With the sensor size of your camera, you start incurring diffraction at about f/11. While you're gaining depth of field by going to f/25, you're loosing sharpness.

 

[SkyPapa]

Thanks Doug. I had forgotten that about APC.
Edit; actually I read somewhere that it is f11 for my camera.

This was just the latest attempt though.
I have not had better success with f8.

I just thought of mirror up too. Big difference?

 

[BlueCorn]

I use mirror lockup all the time. It's certainly worth a try.

What strikes me as odd, in your pictures, is that nothing seems to be in focus. If it was a depth of field thing I'd expect to see something in the frame that's sharp.

 

[SkyPapa]

I use mirror lockup all the time. It's certainly worth a try.

What strikes me as odd, in your pictures, is that nothing seems to be in focus. If it was a depth of field thing I'd expect to see something in the frame that's sharp.

Yep, That's my problem.

When shooting flowers or bugs with the same setup, I always have an area of focus and sharpness. I know this lens has a very shallow dof but as you said that's not the problem here.

 

[Misled]

I don't see your tank type mentioned. Are you shooting through curved glass???

 

[SkyPapa]

I don't see your tank type mentioned. Are you shooting through curved glass???

Nope, standard 180. Shooting straight on with a little elevation on some.
Lens is as close to the glass as necessary to to fill the frame.

 

[Recty]

Just for kicks...

I would lower aperture to around f/5.6 or so. Use a high shutter speed, I know you're on a tripod but using a shutter speed of around 1/250th or higher will at least rule out blur due to something moving, be it your camera or your subject.

Take a picture with what you think is a point in focus that is beyond the coral. Then focus ever so slightly back towards the camera, do that about 10 times until you're focusing closer to the camera than the coral is. Go review those pictures and see if where the depth of field hits you have anything in focus.

If both of those pictures dont return anything at all in focus, then I dont know what to tell you. I know you said straight on with a little elevation, in my experience with macro of corals if you're not perfectly straight on, you're going to see some slight blur. What might be slight elevation to you might be a huge amount of elevation to me, so it depends what you mean by slight.

Hope that helps.

 

[SkyPapa]

Recty, that sounds like a good plan.

I did some other experimenting.

Here a 2 shots from the same distance ,+/- inch or 2.

1st one in my office.
Handheld, AF on, VR on, f5.0 and 1/15s.

Good focus.

Second shot back at tank.
Same parameters except shutter was 1/60, which should be better for shake than the above shot.

Maybe I have defocusing tank glass.

 

[Wolverine]

I agree with Recty about needing to be really straight on.

Another little trick, if you have it available, is to use liveview. You can zoom in even more on that, sometimes to just a few polyps in the middle of the coral in the frame. If you get those into focus on the screen, then the rest of your shot should be pretty good.

 

[SkyPapa]

The birdsnest above was shot straight and level.
It's better but not great, it does say that the elevation I had on the eflo is a lot of the problem.

Ok, here is another one that is probably the most straight on and level.
This is from before with the tripod.

Still not there.

Edit;
This was at f25, so I need to try again tomorrow.

Thanks for the help folks.

 

[DetectiveTofu]

Are you using manual focus?
Is VR turned on when you are using a tripod? When you're on a tripod, VR can introduce minute movements causing blur, IME.

 

[Reef Bass]

Your non tank shots demonstrate your equipment is good.

IMHE, shooting at any angle other than totally and utterly straight through the glass reduces / ruins clarity and focus. Sometimes I'll press my lens hood against the front of the tank and check to make sure it is touching glass all the way around the hood (verifying perpendicularity - is that a word?).

It seems to me that your last pic, where you were more "level", is considerably sharper. As you pointed out, opening your aperature from f25 should also help.

You said you were using a remote trigger, so that should eliminate any manual shutter release pressing induced shake.

Any chance the diopter adjustment on your view finder is causing you to misread focus?

I shoot my corals using remote live view almost exclusively and that allows me to see the image on my large laptop screen and be very precise with where I set the focal plane before I cause the camera to fire. You might give that a try (while shooting straight through the glass at a midrange fstop using a remote shutter release while on a tripod, etc...).

 

[SkyPapa]

Yes, Detective, I was on a tripod and VR was off.

Reef Bass- The diopter is set for my for reading vision but it is maxed and may be off.
However, I still use the focus indicator to confirm.
It may not be focused where I think, but it should be in focused somewhere, shouldn't it?

I tried using the regular lcd live view and zooming but I wasn't happy with the focus that way either.

For remote live view, don't you need Nikon Control Pro, which is kinda pricey isn't it?

I haven't had the opportunity to try again, I 'll post when I do.

Thanks for the replies.

 

[Reef Bass]

IMO, the lens could be set to focus on subject but angling through the glass would blur / distort the image so as to appear unfocused. The fact that you can get a clear, focused image when not shooting through glass hints to me that the issue is your alignment with the glass.

The EOS Utility software which I use to shoot remote live view came with my camera at no extra cost. I just inserted the disc into my laptop, installed the software and got busy with it.

Definitely post some more pics. Have you tried shooting something in another tank?

 

[SkyPapa]

Yea, it was probably from not being level. I 'll get it.

It seems Nikon is pretty bad about software. No 64 bit support for PP software which is not free and the remote software is another $150.

 

[maroun.c]

I'm very sure you're suffering from distortion becuase of shooting at an angle to the glass. Try shooting perfectly perpendicular to glass and things should start improving.

 

["Umm fish?"]

Try this: Turn on your flash and push up the shutter speed to 100. Your exposure meter will be way off the low end. Try it anyway. With the flash on, the colors won't be great, and you might be a little under-exposed, but you can at least see whether you are getting movement in your tripod caused by the slow shutter speed.