Troubles with Nikon D70s SLR

[Slick Fork]

Just for comparison and to demonstrate spot metering vs pattern metering...

This first shot is using the pattern metering, regular jpeg "macro" mode. In this picture it looks like it metered more for the background and overexposed the coral. It was also one of the first 20 pictures I took with the camera so there are probably a couple of dumb mistakes in there!



Here's a shot I took of the same coral a day or so later using the spot metering mode and the raw output. No Macro lense, just the 18-70mm. I didn't do anything to the picture, just straight converted it into a jpeg and it turned out pretty good.

[Gooly001]

The trick to shooting through a fish tank is understanding the concept of White Balance. Although it is a simple concept, I find it hard to explain myself so here are some info off the internet:

http://www.dpreview.com/learn/?/Glos...Balance_01.htm

http://www.photoxels.com/tutorial_white-balance.html

http://www.cambridgeincolour.com/tut...te-balance.htm

So what you should do is set something white inside the fish tank and fill up the frame with it. Then manually set your white balance so that the camera adjusts it meter accurately. Recompose the scene without the white object and shoot. This should give you a more accurate color reproduction then using AWB. A caution for using a white reflective object is that it may cause your cameras exposure meter to under expose the scene, making it look darker then it is. To compensate for this set your manual exposure control to 1 or 2 stops ( depending on the white object ) to overexposing the scene.

Another way to control White Balance is to shoot in RAW. Shooting in RAW, your camera will not preselect a specific White Balance for you, but rather shoots the scene as it sees it. Using an editing software such as Nikon Capture you can easily correct the photo to the appropriate White Balance setting. Editing with a RAW software is a lot easier then having to mess around with Levels and Curves in Photoshop.

Another tip is to shooting close up macros with an aperature of around f/8 or f/11. Using f/8 or f/11 the whole macro object will be relatively sharp but you might need a tripod as the shutter exposure can get low resulting in a blurred image.

If you try shooting with an aperature value of f/2.8, you can increase your shutter speed, therefore you can hand hold your camera; however the focus distance is very shallow and you may only have a sliver of the macro image in focus. Luckily this is a digital world and it is cheap to erase and try again.

Because you are shooting through water and water magnifies, you need to shoot straight on perpendicular to the object or else you will get a horrible magnifying effect. Make sure that your lens is positioned as close to to object as possible to help reduce magnification. You can also move the object closer to the front of the fish tank so that you are not shooting through much water. Hope some of these tips will help.
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[Delphinus]

Just adding a link, I found this page on presetting the white balance on the Nikon D70s:
http://photo.net/bboard/q-and-a-fetch-msg?msg_id=00CWry

Question, what are folks using for setting white balance? Piece of acrylic, or ... ?

[Gooly001]

Here are some of my macros shot with f/2.8. Note the limited Depth of Field and some unsharpness as most were shot hand held. Another thing to notice is that with the shallow depth of field, the background is now pitch black because of the faster shutter speed, there is not enough time for the camera to get full exposure on the background therefore rendering it black.


















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[Jason McK]

Originally Posted by R.A.D.

Here are some of my macros shot with f/2.8. Note the limited Depth of Field and some unsharpness as most were shot hand held.

Marco Lenses by nature have very narrow depth of field. it's the physics of the Lens elements. The only way to increase depth of field is to decrease magnification.

Cool shots BTW
J

[Gooly001]

It's not the magnification but rather the ability of the macro lens to focus down to a few inches. Most conventional lenses have a minimum focus distance of 2-4 feet. A true macro lens will allow the user to focus within inches sometimes mm to the object. Although this may seem like an increase in magnification because you are focusing so close it is rather the macro lenses nature to focus down so tight and that is why they cost so much. If I selected a higher aperture on the lens ie f/16-f/22 and had enough lighting, the result would be a much sharper image that is focused front to back. Most photographers use f/2.8 as a setting when shooting close up is because they want their subject to be sharp but the background to be blurred so that it will not distract the viewer.

True magnification is dependent on the size of the lens that you buy. ie 50mm, 100 mm, 200mm etc..

If I had a 60mm macro and wanted to take a macro shot, I might have to be as close as 1 inch away from my subject. However, if I had a 105mm macro I can now shoot the same image but be further back. Both shots I can select f/2.8 and still get the same blurred and sharpness effect. The only difference is that one lens is magnifying almost twice the other and I can stand further back.
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[Gooly001]

Delphinus,

Try using a clean piece of white PVC piping. If you find that your image is darker then it seems, set your exposure compensation to +1 EV (exposure value). If this is still too dark then +2 etc....make sure that you don't blow out the rest of the image. In other words, keep an eye on areas with highlights so that they don't appear too bright and compete with the subject that you are photographing.
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[Jason McK]

Originally Posted by R.A.D.

It's not the magnification but rather the ability of the macro lens to focus down to a few inches. Most conventional lenses have a minimum focus distance of 2-4 feet. A true macro lens will allow the user to focus within inches sometimes mm to the object. Although this may seem like an increase in magnification because you are focusing so close it is rather the macro lenses nature to focus down so tight and that is why they cost so much. If I selected a higher aperture on the lens ie f/16-f/22 and had enough lighting, the result would be a much sharper image that is focused front to back. Most photographers use f/2.8 as a setting when shooting close up is because they want their subject to be sharp but the background to be blurred so that it will not distract the viewer.

True magnification is dependent on the size of the lens that you buy. ie 50mm, 100 mm, 200mm etc..

If I had a 60mm macro and wanted to take a macro shot, I might have to be as close as 1 inch away from my subject. However, if I had a 105mm macro I can now shoot the same image but be further back. Both shots I can select f/2.8 and still get the same blurred and sharpness effect. The only difference is that one lens is magnifying almost twice the other and I can stand further back.

I have to disagree the lens elements in the marco lens completely change the rules of normal lenses. Depth of field is dependent on the positioning of the lens elements and not f-stop. stopping down to f22 from f2.8 will gain you millimetres of depth of field where as minor decreases of magnification will gain you centimetres.

Anyway. This is usually not a problem with Tank photography as you are never mm from you subject.

Depth of Field Information

J

[Jason McK]

Originally Posted by R.A.D.

R.A.D could you take this shot again with a range of f-stops.

Sorry I do not currently have a DSLR I do have 7 film cameras but that will take way to long to perform the experiment.

J

[Gooly001]

I took some time and shot some more macros yesterday. I didn't do a DOF comparison cause....well...I wasn't really thinking about it. Anyways, here is the detail on how I shot and what I did with post editing software:

Camera: Nikon D70s
Lens: Nikon 105 f/2.8 Macro
Aperature setting: f/16 on all shot
Shutter setting: 1/8-1/25
Camera Mode setting: Aperature Priority
Exposure Metering: Nikon Matrix Meter
White Balance: Preset/Manual, WB metered on white PVC
coupling
Tripod: Yes, must due to low shutter speeds and
close focus
Distance of lens to subject: 2.5 inches
Image File: jpeg

Post Edit Software: Photoshop CS
Levels: Auto Levels
Sharpness: Unsharp Mask
Image Cropping: NO

The camera was mounted on a tripod.

Camera setting was on Aperature Priority mode set to f/16 for maximum DOF.

I took a piece of 2" PVC and positioned it as close to the front glass as possible. I wanted to use the stand as a stage to set my corals onto.

I set my White Balance mode on my camera to "Preset White Balance", then I filled the frame with a close up of the PVC pipe. This tells my camera to set all colors using the PVC white as a reference point.

I then took individual corals and placed them on top of the PVC coupling and positioned myself as close as I could using my 105mm macro lens. The lens allowed me to position my tripod 2.5 inches away from the front of the tank. The corals were only a few mm away from the glass inside the tank.

I had to use my self timer mode because there wasn't going to be enough lighting to prevent blurrness. Also, because I was focusing so close any minute movement will also blur the image.

The tank is a 45 gallon frag tank and the lighting is 2 175 watt 14,000K bulbs.
No supplemental Actinics were used because I did not have any. I wished that I had some because it may have enhanced some of the corals colors.

Anways, I hope that the above info helps.

Jason, disagreeing with each other is tiring and I do not want to pursue the debate any longer. I find that it really isn't helping anyone and the whole point of the thread is to provide tips and tricks to tank photography. Debating magnification technicality does not help in this regard. So I agree with you that we shall remain to disagree and I do not want to confuse people any more then we may have. The point of photography is to create an image that is eye appealing or an image that makes a person think and reflect. At the end of the day, how you created the image doesn't matter.

Cheers.
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