Microsoft Cliplets - Project 1.

Microsoft Cliplets - Project 1. 

First trial. 

Couldn't find any other model except for my barbie...next time, I'll look for a live model.

Aperture and Depth of field

This is an illustration for my facebook  Photography group: Arunachal Photography and Film Lovers.

To understand Photography better and in order to have more control over one's photography it is important to get the basics of the camera function first. For that one need to understand, Aperture, Shutter Speed and ISO/ASA. 

Today, I will just touch the topic of Aperture and Depth of field resulting with the change of aperture.

What is Aperture?

Aperture is denoted by "f". An aperture is a hole or an opening through which light travels. Aperture refers to the diameter of the aperture stop rather than the physical stop or the opening itself. The size of the stop is one factor that affects depth of field  (see below). Smaller stops (larger f numbers) produce a longer depth of field, allowing objects at a wide range of distances to all be in focus at the same time (like in the photo. Eg. f/16.
The aperture stop of a photographic lens can be adjusted to control the amount of light reaching the film or image sensor. In combination with variation of shutter speed, the aperture size will regulate the film's or image sensor's degree of exposure to light. Typically, a fast shutter will require a larger aperture to ensure sufficient light exposure, and a slow shutter will require a smaller aperture to avoid excessive exposure.

  

A device called a diaphragm (see the photo above) usually serves as the aperture stop, and controls the aperture. The diaphragm functions much like the iris of the eye – it controls the effective diameter of the lens opening. Reducing the aperture size increases the depth of field, which describes the extent to which subject matter lying closer than or farther from the actual plane of focus appears to be in focus. 

In general, the smaller the aperture (the larger the number), the greater the distance from the plane of focus the subject matter may be while still appearing in focus.

The lens aperture is usually specified as an f-number, the ratio of focal length to effective aperture diameter. A lens typically has a set of marked "f-stops" that the f-number can be set to (see photo above). 

A lower f-number denotes a greater aperture opening which allows more light to reach the film or image sensor.

What is depth of field?

Depth of field (DOF) is the distance between the nearest and farthest objects in a scene that appear acceptably sharp in an image. As you can see in the above photo, the depth of field is shallow in the widest aperture and it becomes considerably wider and sharper as the aperture decreases. 

As the depth of field becomes deeper and more in focus with the aperture diaphragm decreasing the light hitting the sensor or film pane also becomes lesser which results in slower shutter speed. With slow shutter speed, the camera becomes slower thus prone to shaky and blurry photos. Thus, it is important to use a tripod in such a situation or increase the ISO of the camera.

*Source Wikipedia. Diagram/ drawing of the aperture opening on the first photo taken from web.

MINOLTA MC ROKKOR 1:1.2 f=58mm

I won a bid on MINOLTA MC ROKKOR 1:1.2 f=58mm lens with the No. 2768478 from ebay.in for Rs.10,000 plus Rs.450 Shipping fee. The price of the lens is on the expensive side (for me). This is the fastest lens that I have had or even used till date and also it will be my 4th 58mm lens after the 3 HELIOS lens that I have. Pretty much excited about it. 

I picked it up from the courier service- Bluedarth this evening and it was only a while ago that I could test it so here are few of the test photos with the photo of the lens.

I have used my cousin- Hukpi and my big Barbie as models.

 MINOLTA MC ROKKOR 1:1.2 f=58mm under the light for inspection. It had few fungus marks on the rear side of the lens but it doesn't show even in small aperture so I am happy with the lens. 

***Tips: When buying old/ used lens, inspect it under strong light and see through it or if there are no natural light then lit a torchlight through it and check for possible fungus, dust and scratches. Usually small scratches and even few dust and fungus marks doesn't affect the photo quality but look out for the major damage which may soften the image.

Taken with Canon 40D and Super-Takumar 50mm f/1.4 lens. ISO-200, Exposure time 2.5 Sec, Aperture- f/8 with a macro tube.  MINOLTA MC ROKKOR 1:1.2 f=58mm  on Olympus E-Pl2. The lens is large and stands out but like other Minolta Manual lens, it is built well and looks good.

 ISO- 400, 1/2sec, f/1.2, pattern metering.

Hukpi, my 10 yrs old cousin. Taken in the widest aperture f/1.2, I am not dissapointed. It was taken in  very low light situation, handheld and for me it is quite sharp enough. 

ISO-200, 2sec, +1 step, pattern metering, f/1.2. Set on a tripod. 

Barbie under the distant street light. 

 ISO-200, 1.6sec, +1 step, pattern metering, f/1.2. Set on a tripod. 

 ISO-200, 0.6sec, +1 step, pattern metering, f/1.2. Set on a tripod. 

 ISO-200, 2.5sec, +1 step, pattern metering, f/1.2. Set on a tripod. 

 ISO-200, 1.6sec, +0.7 step, pattern metering, f/1.2. Set on a tripod. 

 ISO-200, 4sec, +0.3 step, pattern metering, f/2.8. Set on a tripod. Here, I decreased the aperture to f/2.8. One can see the polygonal bokeh pattern behind because of the 8 bladed diaphragm.

 ISO-200, 1.6sec, +0.3 step, pattern metering, f/1.4  Set on a tripod.

ISO-200, 2.5sec, +0.3 step, pattern metering, f/8. Set on a tripod. It is a sharp lens at all the apertures. 

Seen here is a Yashica 35 GSN, a common, affordable and very popular rangefinder camera with a telephoto and wideangle converter filters.

*Note: All the photos were shot in JPEG and re-sized to a smaller size in Photoshop to share online since my net is slow and also contrast +5 added in PS4. Otherwise no other editing/ post processing done.

I have not extensively tried the lens but after testing it today, I am very happy with the lens. It is sharp at all apertures. Worth the money and the hype.

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24.08.2013, Saturday

I went out and clicked few more trials in daylight at the widest aperture f/1.2.
The lens and sharp and I am happy. Best thing about the lens is at all aperture values the exposure value is not compensated but at f/8, f/11 and f/16 I see change in the white balance which can easily solved with manual white balance (not shown in the photos).