Playing With Lenses: December 2017

Sunday 24 December 2017

Something on Starbursts

I love starbursts! On sinking sun, on a night street light or just a little glitter in the background.
You might know that there are at least two common ways to create the starburst effect in a photo.

First one is by using a Cross Screen filter, reviewed in an earlier blog on the Hoya CS. These typically give you longer rays, and the ability to choose the angle of the rays.

Starburst by using Hoya CS Filter

The other ways to create starbursts is by selecting a very small aperture, where the rays are created by light diffraction in the corner between two aperture blades.

What is less known is how to control the number of rays within your starburst. One corner between two blades creates two rays. One stronger one in the corner where two blades meet, and one less stronger one at the opposite side. The more blades in a lens, the more corners between blades, the more rays you will see in the photo.

If you have an even number of blades, the ray on the other side will overlap with the ray caused by the opposite corner of two different blades. If you have uneven blades, there is no opposite corner, so no rays to over lap. As a result, you can use the following formula's:

If an even number of blades, the number of rays is equal to the number of blades
If an uneven number of blades, the number of rays is double the amount of blades

The sharpness of the blades is also a good test to measure the sharpness of the lens when aperture is mostly closed.

Some Samples:

Starbursts caused by 4 blades

Starbursts caused by 7 blades

Starbursts caused by 6 blades

Starbursts caused by 8 blades

Sources:
B&H Photo Video: Create compelling star effects sun stars starbursts photos

Monday 18 December 2017

The Value of Cheap - part 2: Nikon AF Nikkor 50mm 1.8 D

Cost: free ($132 new at B&H)

OK, I was very lucky here. My wife has used this lens for years as a semi-professional photographer on her Nikon D800. One day, the auto focus started failing, and due to the low cost for new, she decided to replace the lens instead of send it for repair, and hand the old lens to me. As the lens would only work manual on my camera, it was a great fit! This is one very nice lens.

Although it is also a lens in the budget friendly AF D series, it is much better build then the previously reviewed AF D zoom lens. It feels more dense, well constructed, but still a very light weight, small profile, lens. Focus and aperture rings work well, although not as smooth as some older lenses in the good old days. The aperture ring has a loud click, making this lens unsuitable for professional video.

Image quality is unchallenged. Some regard this lens as one of the sharpest lenses ever made by Nikon. For sure sharper than current, much more expensive (think < $2000) zoom lenses. Colors are great, good contrast and almost no distortion or color fringing. There is a reason that many professional photographers use this lens as one of their default lens, especially for low light photography.

Due to the quality, this lens is still manufactured and sold by Nikon. Yes, you can opt for a more expensive "G" quality lens, but your results will not be better. Maybe smoother handling, weather proofing, but in most cases, you save your dollars and by another lens in addition.

So, the value of cheap? In this case, very high, even if you have to pay full price. This lens will for sure go in "will use again' drawer. Hopefully soon!

Lens Specification:
Focal Length: 50mm
Maximum Aperture: F1.8
Minimum Aperture: F22
Image Format: 35mm
Lens Mount: NF
Optics:6 elements in 5 groups
Blades: 7
Focussing: Manual and Auto Focus on suitable camera
Minimum Focus: 45cm
Filter Size: 52mm
Weight: 157g
Length: 39mm
Production: 2007-now
Serial Number: 2692060
Made in: China

More information on Nikon Corporation

Samples:Taken with Viltrox NF to E-Mount Focal Reducer

1/40 sec - ISO200 - Handheld

13/10 sec - ISO100 - Tripod

3 sec - ISO100 - Tripod

8 sec - ISO100 - Tripod

8/5 sec - ISO100 - Tripod

6 sec - ISO100 - Tripod

13/10 sec - ISO100 - Tripod

13 sec - ISO100 - Tripod

1/100 sec - ISO200 - Handheld

Sources:

Wikipedia: Nikon
Ken Rockwell

The Value of Cheap - part 1: Nikon AF Nikkor 35-80mm 1:4-5.6 D MkIII

Cost: 25$, including SLR (average market price $25, lens only)

Let's start with the positive. Due to the low weight and versatile range, it can be easily used for travel, close-ups, landscapes, and just doing some photo-walks. Mostly sold as a kit lens, it was targeted for the budget minded consumers, going with the low end of the SLR's. It's fairly sharp in the center, and renders nice colors. And there it stops...

Used as manual lens, it's pretty much a pain in the ... The focus zoom ring is so small that you fingers can barely handle it. This is likely not a problem when used with auto focus, but as my camera and adapter does not support auto focus, I will never know. The focus ring is also very flimsy, making accurate focussing hard. The whole barrel is also wobbly. The zoom ring is slightly better, providing a decent grip, but still flimsy. In short, it feels and handles like a very cheap, fragile, plastic lens. It even comes with a plastic lens mount.

Image quality is questionable. Sharp in the center when using middle aperture, soft in the corners, and the lens is not able to resolve the resolution of the sensor. When pixel peeping, you can see the loss in details, and the noise it generates. Of course, that fact that this is a slow lens, does not improve the image quality overall.

This is however the third version of this lens, made in Thailand. The first version, made in Japan, had 6 elements in 6 groups and with a metal lens mount. This version was a little easier to use, at is was designed with also manual users in mind. On the second lens, the manual focus seemed to be designed as an after-though, of for emergencies when the auto-focus malfunctions. Some say that the Japan made lens was better in quality then it's successors where more concessions were made to reduce the price. The second lens was also made in Thailand, with the same design as the 3rd, but with a metal lens mount.

So, it's not a totally crappy lens, but I would not use it if you want to make quality pictures. But as a cheap, lightweight lens, it might have it's purpose. It can still be used when you auto focus fails, and if the lens get damaged (should not be to hard to do), you haven't lost to much. So the value of cheap is low in this case, but the price does make it easily replaceable.

Lens Specification:
Focal Length: 35-80mm
Maximum Aperture: F4
Minimum Aperture: F22
Image Format: 35mm
Lens Mount: NF (plastic)
Optics: 8 elements in 6 groups
Blades: 7
Focussing: Manual
Minimum Focus: 35cm
Filter Size: 52mm
Weight: 180g
Length: 67mm
Production: 1995-2006
Serial Number: 99610246
Made in: Thailand

More information on Nikon Corporation

Samples:
Taken with Viltrox NF to E-Mount Focal Reducer

1/1000 sec - ISO100 - Handheld

1/200 sec - ISO100 - Handheld

1/250 sec - ISO100 - Handheld

1/100 sec - ISO1600 - Handheld

4 sec - ISO100 - Handheld

More samples here

Sources:

Wikipedia: Nikon
Mir.com
NikonZooms.com

Monday 4 December 2017

Flower Power: SMC Pentax-A Zoom 1:4 70-210mm

Cost: 29.99$ (average market price $86.93)

I was both excited and reserved to try this lens. At one side, it's an 80's zoom, not a prime time for zoom, but on the other hand, it was getting really good reviews online. My experience is somewhere in the middle.

It's a beautiful, well designed one-touch, slide to zoom and turn to focus, lens of epic proportions, with a nice build-in hood. To get to a fast F4 across the whole zoom range, zoom lenses of this time had to be big, until more compact lenses were designsed. My Sony camera almost disappears next to it. Yes, it's large and heavy with a lot of solid metal. The weight of the barrel alone seems to cause a lot of zoom creep with many users. I did not really had that problem, unless I held the lens completely vertical. Both zoom and aperture were extremely smooth, almost as fresh out of production.

This lens is capable of being very sharp, but when using large apertures, it does show some problems with sharpness and severe purple color fringing. So as long as you remain a few steps away from open aperture, and avoid maximum zoom, the quality is excellent. However, due to the size and weight, it's really hard to focus properly (manually of course) when using it handheld, resulting in a high percentage of wasted pictures. It should be used on a tripod, but as it does not have a tripod attachment on the lens itself, and lacks the space to put on a lens collar, you have the mount the camera itself on the tripod. And this lens is just to heavy to be carried by the camera mount alone, again resulting in less stability, and therefore less sharpness. So, capable of good quality, but not practical in usage. I prefer a more modern zoom design that is more compact and has less weight.

From online reviews, it seems this lens really shines when being used for close-up photography, especially with 8 blades giving potential for a smooth Bokeh. I did not have the opportunity to try it out on my walks as it is getting a little late in the year for flowers. So, a good excuse to take this lens out again in the summer for some Flower Power.

To combat partial reflection, Pentax developed chemical coatings for the lens surfaces with minimum light loss. SMC is "a remarkable seven-layer lens coating process that cuts the reflection ratio down to just 0.2% per lens surface. The result is a dramatic improvement in both color fidelity and brightness and the elimination of flare and ghost images."

SMC was patented and first applied in 1971, when Pentax was still making screw mount equipment. The multi-coated lens lines changed from Takumar and Super-Takumar to Super-Multi-Coated Takumar and later on to SMC Takumar. SMC Pentax was used for the newly introduced K-mount lenses. Pentax's SMC is still today considered as one of the best lens coatings on the market.

Lens Specification:

Focal Length: 70-210mm
Maximum Aperture: F4
Minimum Aperture: F32
Image Format: 35mm
Lens Mount: PK
Optics: 13 elements, 10 groups
Blades: 8
Focussing: Manual
Minimum Focus: 120cm
Filter Size: 58mm
Weight: 680g
Length: 149mm
Production: 1984 to 1988
Serial Number: 5249729
Made in: Japan
More information on Pentax

Samples: