snubbr.com

Depth of field - follow up on 1:1 photography-thread
I recently asked about 1:1 photography and got some very helpful answers to that. Thanks a lot..

Here are the results and my next question regarding product photography..

As you can see from this first picture, it is nice and and sharp and I'm quite happy with it. (Still, ideas for improvements are welcome)..

Http://picasaweb.google.dk/...alfleha/ProductPhotos/photo#5202752321472760690.

However, this second picture, is not quite so good. The front is sharp, but the back of the product is blurred. I tried to experiment with different apertures, and at the highest f-numbers, sharpness (or rather: lack thereof) was the same in all the picture. Lower f-numbers, of course didn't help..

Http://picasaweb.google.dk/...alfleha/ProductPhotos/photo#5202752145379101538.

I also tried to experiment with the distance from the camera to the target, but very soon the target occupies so little of the frame that I won't be able to enlarge it to the sizes I need..

My equipment is a D80 and Nikons new 60mm macro..

How do I get the entire product sharp and large enough to occupy the entire picture??? Do I need another lens or can I tweak something to make it work?.

Thanks for any help...

Comments (5)

Alfleha wrote:.

I recently asked about 1:1 photography and got some very helpfulanswers to that. Thanks a lot..

Here are the results and my next question regarding product photography..

As you can see from this first picture, it is nice and and sharp andI'm quite happy with it. (Still, ideas for improvements are welcome)..

Http://picasaweb.google.dk/...alfleha/ProductPhotos/photo#5202752321472760690.

However, this second picture, is not quite so good. The front issharp, but the back of the product is blurred. I tried to experimentwith different apertures, and at the highest f-numbers, sharpness (orrather: lack thereof) was the same in all the picture. Lowerf-numbers, of course didn't help..

Http://picasaweb.google.dk/...alfleha/ProductPhotos/photo#5202752145379101538.

I also tried to experiment with the distance from the camera to thetarget, but very soon the target occupies so little of the frame thatI won't be able to enlarge it to the sizes I need..

My equipment is a D80 and Nikons new 60mm macro..

How do I get the entire product sharp and large enough to occupy theentire picture??? Do I need another lens or can I tweak something tomake it work?.

The second image is of a much larger object which extends further back from the camera, so depth-of-field is always going to be more of a problem. The screw in the first picture is relatively shallow (only a few mm from front to back) to d-o-f is less of a problem..

Of course you need to fill the frame with your subject, otherwise you just end up having to enlarge it more, and any slight loss of sharpness becomes magnified (in fact, a proper calculation of depth of field includes the degree of magnification of the image from sensor to print for this exact reason: see.

Http://www.cambridgeincolour.com/tutorials/DOF-calculator.htm.

So standing further back won't help..

The simple advice is to use the narrowest aperture you can, and use a tripod to hold the camera steady during the long shutter speed that will result. But, at short distances, your depth of field is always going to be very small. For example, with your camera and a 60mm lens at f/16, with a distance to the subject of 1 foot, the d-o-f is from 29.1 to 30.9 cm, i.e. less than 1 cm either side of the focal plane: see.

Http://www.dofmaster.com/dofjs.html.

And you can do these calculations for yourself. So if you have an object that is 2 cm deep you should be just about OK if you shoot it from 30 cm away at f/16, as long as you focus on the *middle* of the object and not the front surface (in which case the back will be out of focus)..

There's not much you can do to avoid this issue... the physics just gets in the way. if you use extremely narrow apertures you will end up with a significant loss in image quality due to diffraction effects which will offset the improved sharpness due to greater depth of field..

Best wishesMike..

Comment #1

The laws of optics are against you..

At 1:1 magnification the basic equation for depth of field using lens optics can be reduced to:.

DOF <- 4C(f-stop) where C is a constant characteristic of the camera. (my equals key is broken!) Notice that focal length doesn't matter..

Anyhow, all you can do is use a different kind of imaging system, like a scanner, or use software that assembles a stack of through focus images (there is such a plug-in for imageJ.)..

Comment #2

Got a lens cap? Some tape? A piece of string? Needlenose pliers?.

Set up the shots, one after another..

Then tape the end of the string to the lens cap, and put it on the camera..

Hold the other end with the pliers, and stretch the string so that it reaches one end of the screw, and then the other end. Notice how there's not much difference in distance?.

Repeat with the other thing. Notice how much more difference there is in the distance to the near part and the far part?.

So, to get the "deeper" object sharper, you need to turn it, or move it farther away, or focus part way between front and back, or use a smaller aperture (bigger number), or get a camra or lens that tilts..

BAK..

Comment #3

BAK wrote:.

Got a lens cap? Some tape? A piece of string? Needlenose pliers?.

Set up the shots, one after another..

Then tape the end of the string to the lens cap, and put it on thecamera..

Hold the other end with the pliers, and stretch the string so that itreaches one end of the screw, and then the other end. Notice howthere's not much difference in distance?.

Repeat with the other thing. Notice how much more difference there isin the distance to the near part and the far part?.

So, to get the "deeper" object sharper, you need to turn it, or moveit farther away, or focus part way between front and back,............BAK.

A great hint regarding setting up a close-up shot!.

There's a flat slab of space that is in focus in front of the lens. The object should be placed in this slab as appropriate for the scene's purpose..

Tilt lenses, etc, change the orientation of the slab but not it's thickness (its thickness is proportional to f-number.).

Dave.

PS, a minor point is the string demo mention by BAK should not be taken to mean there is a spherical slab of space in focus. It is a flat slab of space. If a tilt lens is used the slab may be tilted. The thickness of such a tilted slab is not strictly constant - I think it gets thicker in proportion to distance for macros...

Comment #4

It looks like your point of focus is the very front of the object. Try this....

Frame your shot as before, then move the camera further away by 1/3 the depth of the object. Focus on the object and engage your focus lock. Now move the camera forward to the original position..

The idea here is to attempt to utilize the usable depth-of-field that is in front of the focus point, instead of depending solely on the DOF that is behind the focus point..

Good luck!..

Comment #5

Click Here to View All...

Sponsored Amazon Deals:

1. Get big savings on Amazon warehouse deals.
2. Save up to 70% on Amazon Products.


This question was taken from a support group/message board and re-posted here so others can learn from it.

 

Categories: Home | Diet & Weight Management | Vitamins & Supplements | Herbs & Cleansing |

Sexual Health | Medifast Support | Nutrisystem Support | Medifast Questions |

Web Hosting | Web Hosts | Website Hosting | Hosting |

Web Hosting | GoDaddy | Digital Cameras | Best WebHosts |

Web Hosting FAQ | Web Hosts FAQ | Hosting FAQ | Hosting Group |

Hosting Questions | Camera Tips | Best Cameras To Buy | Best Cameras This Year |

Camera Q-A | Digital Cameras Q-A | Camera Forum | Nov 2010 - Cameras |

Oct 2010 - Cameras | Oct 2010 - DSLRs | Oct 2010 - Camera Tips | Sep 2010 - Cameras |

Sep 2010 - DSLRS | Sep 2010 - Camera Tips | Aug 2010 - Cameras | Aug 2010 - DSLR Tips |

Aug 2010 - Camera Tips | July 2010 - Cameras | July 2010 - Nikon Cameras | July 2010 - Canon Cameras |

July 2010 - Pentax Cameras | Medifast Recipes | Medifast Recipes Tips | Medifast Recipes Strategies |

Medifast Recipes Experiences | Medifast Recipes Group | Medifast Recipes Forum | Medifast Support Strategies |

Medifast Support Experiences |

 

(C) Copyright 2010 All rights reserved.