Untitled

This is the very tip of a tiny squash vine as it curls around. Comments and

critiques are very welcome and constructive criticism is preferred. Thank

you.

Love the close up look.

Hi Kyle,

I like the subject captured very much.

Since you used your 105mm at F/8, i would suggest that you get back from the subject such that the DOF works more to your advantage.

With the Nikon D7000, a smaller , sharper image is easily enlarged (after cropping) to improve the overall effect.

However, if you wanted to emphasize more detail in this vine, then using F/2.8 or F/4 would have been noticeably sharper at the cost of DOF.

Best Regards,  Mike

Its left "hand" is out of focus, I wonder would it help to position the ISO ratings on 400 and use smaller aperture f/16! Worth trying, maybe the ISO 400 and f/16 won't work, then you can try higher ISO rating or experiment with the distance change in the same time! You must try when you once got so near to perfection Kyle!

Best regards!

PDE

Thank you Bob for taking the time to view my photo and leave your kind comment.

Thank you Pierre and Mike for the very detailed and helpful critiques. I think sometimes my macro photos are deceiving in just how small the objects are. Also keep in mind that I intend to print these out at quite large sizes like 24x36 and have made prints of some of my photos at that size. So that has some bearing on how much I can crop down before I lose too much resolution to make large prints. If I was just making photos to share on the internet then I would definitely rely on cropping down further more often. There is a fine balance in play when you plan on printing out a photo.This photo is at 1:1 so I didn't have a lot of room to play with as the vine tip was so small.

I do have another version where I cropped it down to just the curly at the top excluding the "arms" at the bottom. I will upload that when I get a chance. It seems that people like that version better perhaps because the arm closer to the camera is out of focus.

Also Mike correct me if I am wrong but the 105mm only goes to f2.8 when you are focused at or close to infinity. As you focus closer in the max aperture goes down right? In order to take a photo of this at f2.8 I would have been too far away and it would have been tiny in the photo again requiring too much cropping down. Maybe I am being too ambitious with the 105mm and I need to stick to larger objects with it for a while and use a reversed lens or something like that to go to 1:1 or larger.

I would like to again express my gratitude for all your helpful comments and critiques they really do help me when I go out to take photos, I try different techniques all the time based on your comments. Thank you Pierre and Mike.

Cheers.

Hi Kyle,

I understand your printing requirements as I have expressed in my response to your Dragonfly image.

Technically, any lens that is used from Infinity to say 2 feet (close focus) has no perceptible change in the f-stop. When you go into the macro mode, then the "effective f-stop" increases even if the lens is set wide open. For example, a 1:1 using the 105 F/2.8 macro , the effective f-stop is calculated by : (m+1) times the f-stop setting. Where "m" is the image magnification. So at 1:1 (life size) , (1+1) X 2.8 = 5.6. The effective f-stop is now F/5.6. This is for computing exposure only, not DOF. 

So your macro at 1:1 focus (F/2.8 f-stop setting)  requires the same exposure as that the same lens would need taking a picture  a few feet  to Infinity, set to F/5.6.

This is why at  1:1 focus range, it is demanding on lighting, since a fast F/2.8 lens is 4 times slower and requires 4 times the exposure value.

Using an F/8 setting for more DOF at 1:1 macro focus, really behaves like a F/16 lens for exposure required.

Now, if you used an extension tube to obtain a 2:1 (twice life size image)then the F/2.8 setting would be like F/8.4, requiring 9 times the exposure value.

Fortunately, the modern digital cameras compensate for the light received to the sensor automatically, unless the user selects a different exposure value.

Best Regards,  Mike

Thanks for the explanation Mike. I really like to know the math behind the lenses (I am currently working on my 2nd bachelors in Math). That definitely makes sense to me now.

So if I set my D7000 at the max allowable aperture while focused at 1:1 even though the display shows something other than f2.8 the actual aperture is f2.8?

I agree with your comment on the other photo that larger formats are the option, D700 etc. though with a baby on the way I am limited in my camera gear purchasing power so I will try various techniques including the ones you have mentioned here until I get good enough to know which ones work for which photo. Hopefully down the line as you have expressed I can get to a point where my work can propel me into a position where the work supports the means for the work and I can invest in larger formats to get past some of the limitations I am facing right now.

In the mean time I will continue to work on mastering my control over depth of field, exposure, composition, and lighting.

Cheers.

Hi Kyle,

When you set your lens to its physical f-stop, like F/2.8, then that is really F/2.8. If your Nikon D7000 or any camera shows a slower f-stop, it is due to the calculation of light that is received by the sensor.

 At 1:1 , a F/2.8 physical f-stop fills the sensor like it was a F/5.6 lens. Therefore the longer exposure required. However, the lens performance depends upon its design , and usually the faster f-stop (like F/2.8) allows for the highest degree of definition for an excellent lens.

The physics is straight forward. Think of the sensor as a wall in your home. Now place a flashlight close to the wall. You see a bright circle of light. Now as you back away from the wall, the same light is spread out over a larger area of the wall. the circle appears much dimmer, yet we know that it is the same light source.

In macro photography , the lens is the light source to the image plane (the wall). As we get closer to the subject, the magnification increases and the light spreads across the sensor (becomes dimmer). So, while a lens is at a wide open aperture (passing the maximum amount of light it can),  the magnification factor causes that same light to spread out, lowering the light density onto the surface of the sensor.

My very fast and outstanding Carl Zeiss 50mm F/2 macro lens quickly becomes effectively F/4 at 1:1 , yet it maintains it high definition because it is set to F/2.

I trust that your studies go well in Math, and that down the road you can continue to build upon your camera gear.

All the Best,  Mike