Pentax 100mm f4 Macro lens Review

Another great manual focal Pentax lens from thirty odd years ago. Many positive comments regarding this lens can be read over on the "Pentax Lens Forum"

Pentax 100mm f4 macro lens

This lens uses a "Heliar" optical design.

• Focal Length:     100mm
• Aperture Range: f4 thru f32 half stops thru to f22  6 blades
• Focus Travel:      350 degrees
• Close Focus:       45cm
• Filter threads:      49mm
• Weight;                370gm

Beautifully smooth focus ring, nicely damped, great lens.

Pentax 100mm f4 macro lens Close Focused

This is a great lens if you like taking shots of insects. Its focal length allows a bit of clearance between you and your living subject, they tend to run or fly away given the chance.
Like its little brother the 50mm it exhibits no aberrations that I can see, no purple fringing no chromatic or general distortions. This lens at f4 does display a small amount of "Coma" at the edge of the frame, it disappears from f5.6 as shown in the picture below.

Pentax K100d 100mm macro at f5.6

 No Coma visible

Eta Carina Region taken with Pentax 100mm f4 Macro Lens

As well as being a close up lens it's also a 100mm telephoto, so if you have an "aps-c" sized sensor in your camera, you get a field of view equivalent to 150mm on "full frame".

Pentax 100mm F4 Macro 100% Crop

Pentax 100mm f4 Macro

more pics to follow

Pentax M 50mm f4 Macro Lens Review

You can read about the Pentax 50mm f4 Macro lens on the "Pentax Lens Forum" , and It's well worth the read.
This lens is over 35 years old, and In my view, it's a little ripper.

Pentax 50mm f4 macro lens

It's a very simple lens in that it's based on the Zeiss "Tessar" optical design. Four elements in three groups. The Tessar design lends itself to a sharp and distortion free lens, but this comes at the expense of speed.
You won't find a really "fast" Tessar lens from any company, Zeiss made some at f2.8 actually millions of them. I don't call that fast, I'd like to try one though, think I will.

• Focal Length:    50mm
• Aperture range: f4 thru f32  5 blades  half stops up to f22
• Filter Threads:   49mm
• Weight:             169gm 
• Close Focus:     23.4cm
• Focus throw:     350 degrees approx

The Lens assembly is set so far back from the front you don't need a lens hood with this little fella either.

Pentax 50mm f4 macro lens close focused

You might say "A bit slow at f4" but who cares, once you step outside into the sun you start at f4, or f8
Being wide open at f4 also allows for some nice "bokeh" as you can focus very close to your subject and have an "iris blade free" background blur.

Pentax 50mm f4 macro lens Bokeh

The only down side I have found is at the far end of things, as you approach infinity the focus travel gets rather small, so nailing focus at that end takes a bit more patience.

As the saying goes "a picture is worth a thousand words" so some pictures.
 

All taken with Fujifilm XT-1 Camera

One of those weeds at f4 and 

100% crop at the right.

Nice flower and

100% crop

As you can see very sharp, and as I believe also free from distortion. No only a great close up lens, but also great as a walk around lens as well.

The following two are straight from the camera, not cropped, just compressed a bit.

The bike is a colour shot

Probably f8.Focused on the motor.

Most likely f8 

Flinders St Station, Melbourne, Victoria

Fujinon 55mm f1.8 M42 Lens Review

I recently bought this Fujinon 55mm f1.8 vintage lens for a great price on ebay, It's hard to resist when the price is right.

This is the non EBC (Electron Beam Coating) version which means it only has, most likely a single coating rather than the eleven that EBC involves. Update: Whatever the coating is my impression is very good, I'm loving this lens.

The front element is set back quite a way from the filter threads which may explain why I haven't experienced any flaring, except at really close angles to the sun.

Fujinon 55mm f1.8 m42 mount

Having just dismantled and cleaned this lens I can report that it's of all aluminium construction with a plastic name ring and rubber focus grip. During reassembly I set its infinity focus point to where I wanted it, and then we're good to go.

This lens uses a different optical formula than most similar Japanese lenses of the time.
It uses an "Asymmetrical Planar" design more common with "Zeiss Biotar's"

If you want to use this Vintage lens with most M42 adapters you will need to remove a little tab from the aperture ring.

This tab communicates the aperture position to its original host, that being a 35mm film camera. I nipped mine off with a small pair of very fine jewelers side cutters, then cleaned it up with a very fine file. I have many such tools, as I used to do mechanical watch repairs. The adapter will also have to push in the aperture pin on the rear of the lens as it does not have an "Auto - Manual" switch. In my case I fitted a brass bush over the pin while I had the lens in pieces.

• Aperture:         f1.8 f2.8 f4 f5.6 f8 f11 f16   Full Stops Only. 6 blades.
• Close Focus:  45cm
• Filter threads: 49mm
• Focus Throw: Approx 190 degrees
• Weight:           206gm

The Focus ring is just about perfect for me, with the dimple pattern and the right dampening you can move it easily with one finger and things just snap into focus, as it were. The aperture ring has just the right resistance, clicks positively but smoothly. Not having "half stops" is something that I like as well, I seem to know which "f" stop I'm on without looking.

Until recently I didn't realise how important the "feel" of a lens is, it makes a big difference, almost giving you that that "warm fuzzy" feeling. 

Like a lot of fast vintage lenses, and I'm being really picky, it's just a little soft at the edges wide open, not a bad thing really and there's a tiny bit of purple fringing in high contrast situations, but from f2.8 on, its really sharp, check the comparison down the page. The colours are nice too.

I'm not sure yet, but I think it's the Bokeh that sets it apart, I have other 55mm fast lenses but so far I like this one the best.

I'll have to take more pictures.

Fujifilm XT-1 fujinon 55mm m42 @ f4

 A bee in the back garden 50% crop approx

Fujinon 55mm 1.8 @ f4

fujinon 55mm f1.8 @ f1.8

Some Garden Bees At f 1.8 just resized

Some more Bees At f2.8 resized

For comparison, my neighbours car headlight. Re-sized and cropped.

Reasonably sharp in center

First is at f1.8 the second at f8

Try zooming by holding the CNTL key down and roll the mouse wheel.

At f5.6  Extremely sharp edge to edge

Fujinon 55m f1.8 @ f1.8