Long Depth of Field

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gerryr

gerryr

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I just got my favorite lens for photographing pens back from the repair shop on Saturday and decided to play with it. This is a pen I made last year for submission to Stylus Magazine for their "road test" of fountain pens by PMG members. The pen is about 18.5" from the sensor in my camera and is just about 5" long. The lens is a 20+ year old 55mm Micro-Nikkor and the aperture was f/11. The depth of field calculates out to be 1.15", however, as you can see, the entire pen is in focus.[:0]

20081221462_DOFTest.jpg
 
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I haven't used any variety of 105mm Micro-Nikkor. I wouldn't mind having one, but I would buy an old manual focus version because I don't like autofocus for macro work. Macro lenses in general tend to be extremely well made and very sharp, even the third party lenses are pretty much comparable to macro lenses made by Nikon and Canon. On my D40, the 55mm gives me a field of view comparable to a 82.5mm lens on a 35mm camera which means I have the camera set up about 20 inches from the pen in order to get it all in the frame. The 105 would give me a field of view comparable to a 157.5mm lens and would force me to have the camera even further away, probably 3 feet or so.

Yes, I do shoot a lot of film, but I quit processing it years ago. Processing color film at home can be pretty tricky because it's a lot more sensitive to temperature than black and white.

Roy, there isn't anything wrong with your photos. I'm just playing.:D
 
Gerry,
Reading this is like a foreign language to me.
I think you're saying the picture you're showing can't be done. :D:D:D
Very nice pen. Nice shell too. [}:)][:p];)
 
I'm going to let you guys stew a while before I tell you how it's done. And yes, Gary, you are looking at an impossible photograph.[}:)]
 
Originally posted by gerryr
I just got my favorite lens for photographing pens back from the repair shop on Saturday and decided to play with it. This is a pen I made last year for submission to Stylus Magazine for their "road test" of fountain pens by PMG members. The pen is about 18.5" from the sensor in my camera and is just about 5" long. The lens is a 20+ year old 55mm Micro-Nikkor and the aperture was f/11. The depth of field calculates out to be 1.15", however, as you can see, the entire pen is in focus.[:0]
Click to expand...

I have a reasonable understanding of the concept of DOF; but would not argue if someone said my circle of confusion was not as small as it could be. What I think I know about DOF is based entirely on film cameras and if I am correct, one has to make an adjustment or two accommodate digital cameras.

I am really surprised at the quality of your photo given you have calculated the DOF to be only slightly greater than an inch. To be perfectly honest, something just seems to be out of whack here. Not sure whether it is my knowledge or your calculations. Would you mind posting some of the numbers you used to derive the DOF number? Did you actually do all of the calculations yourself or do you have some sort of DOF computer (either manual or electronic) that generated the result?

And one final comment is that in spite of your comment, the two extreme ends of the pen and the far part of the shell look ever so slightly fuzzy to me. So the suggestion the the entire pen is in focus, is somewhat subjective and might not meet with universal agreement.
 
Randy, depth of field is depth of field. There are some adjustments that need to be made for digital cameras based on the size of the sensor. That's why you won't find any small point and shoot cameras that will go to even f/11. My Konica Minolta Z5 only goes to f/7.1, but it has a small sensor. As far as calculating the depth of field goes, I used an online calculator, http://www.dofmaster.com/dofjs.html .

This photo is obviously a trick. I took 7 photos of the pen, changing the focus a bit for each one. The images were then combined in a program called Helicon Focus. The technique is called focus stacking and there are a few products that do the same thing. I've read that it can also be done in Photoshop using layers, but I don't have Photoshop. The more images that are taken, the sharper the end result will be. If I had taken 10 instead of 7 it would be sharper. To use this technique, it's imperative that you have a rock solid tripod and that nothing move.

This is not something I plan to do every time I photograph a pen, but it may be useful for pens sometimes. Depending on the material, it can easily be more trouble than it's worth.
 
I love digital... You can do what you need to get the very best shot of your pen...

There was a guy a few years ago that took a photo of a real locomotive with him as the engineer, he then photo shopped it and added scenes from his layout... Was about to win the prize when someone shouted unfair...
 
I'm back. Nice trick Gerry.

I was about to make a comment on the 1.x inch DOF. ha Either that or it's a very very short pen. :)

It's funny, we have the exact same lens. 55mm Nikkor is your's the AIS or Non-AIS? I'm in the same school of though that unless you're using a flash and shooting bugs or other things that move, AF is worthless to good macro. Especially when you get down to 1:1 mag or better.

True, you can't fix an 'out of focus' picture. You can use P.S. to 'improve' a slighly soft image (like lens defects) but out of focus is out of focus. :0
 
Originally posted by gerryr

Originally posted by jwoodwright

I love digital... You can do what you need to get the very best shot of your pen...
Click to expand...
True, but only to a point. You cannot fix an out of focus image.
Click to expand...

Well, that may not be true. Remember the original images published from the Hubble telescope? As I remember it, they were able to make some focus and distortion corrections once they knew exactly what portions of the images were out of focus. But then, I don't think any of us have the unlimited funds and resources to do such a thing.
 
nice trick gerryr, particularly the stitching together of the pictures. and of course you can achieve these results if you move up to large format where you can change the fields of perspective on, you can also get lenses for slr digitals that change the perspective but only limitedly. the only problem is i think its an unnatural way to admire a pen; as though your looking down the barrel of a gun. one does look at it this way if your inspecting it of course.
 
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