malykh.com notes: 2023-11

2023-11-29

Viewfinder magnifying eyecups for Pentax DSLRs: DK-21M and O-ME53

I've owned two Pentax DSLRs (*ist Ds and K10D). For a crop sensor camera, they have good pentaprism viewfinders with 0.95x magnification (50mm lens). But I still wanted to increase the viewfinder magnification, especially since I use manual focus lenses a lot.

First I bought the Nikon DK-21M magnifier (1.17x). It almost fits Pentax DSLRs, but it is a bit tight to put on.

But then I found the original Pentax O-ME53 magnifier (1.2x), which fits better. And gives a better image.

Then I switched to Samsung mirrorless cameras in 2010, and the Pentax cameras were sold: the *ist Ds in 2012, the K10D in 2013.

The magnifying eyecups remained unused for a long time, but in 2020-2021 I sold them too, as I had no plans to go back to Pentax DSLRs.

See also related notes:

"Zoom View Finder 1.08-1.60x" magnifier. (2024-04-11)

Image albums:

Pentax

2023-11-27

Riconar/Rikenon 55/2.2: Two types of focusing and background blur

The Riconar 55/2.2 lens has a simplified manual focusing mechanism by moving only the front element instead of the entire lens unit.

The Leica M-Sony FE/E close focus (helicoid) adapter can be used to reduce the focusing distance (see 1 or 2). In the case of the Riconar 55/2.2, however, this adapter (together with the Pentax K-Leica M adapter) allows you to compare both ways of focusing: by moving the front element or by moving the entire lens unit. In the second case, the lens is set to focus at infinity and the close focus adapter is used to focus at closer distances.

This has an unusual effect. Since the position of the optical elements is different when focusing closer than infinity, this results in different image quality and different background blur.

Due to the soft focus, it is difficult to focus with the lens (compared to focusing with the adapter). The focusing distance may be slightly different.

All images were taken with the Sony a7c (FF, 24MP) at f/2.2:

(lens focusing)

(adapter focusing)

(lens focusing)

(adapter focusing)

(lens focusing)

(adapter focusing)

(lens focusing)

(adapter focusing)

(lens focusing)

(adapter focusing)

(lens focusing)

(adapter focusing)

(lens focusing)

(adapter focusing)

The difference is most noticeable at close focusing. Then, lens focusing gives more aberrations (and soft focus), but softer background blur. Focusing with the adapter reduces the visible aberrations, but the background blur looks more like "soap bubbles" (triplet like).

It's like having two different lenses in one.

See also related notes:

Riconar/Rikenon 55/2.2: Samples [1] - FF + close focus (helicoid) adapter (2023-12-05)

Image albums:

2023-11-25

Hyundai XTeer Gasoline Ultra Efficiency 5W-20

Another xW-20 motor oil (I still prefer this viscosity).

Hyundai XTeer Gasoline Ultra Efficiency 5W-20 (4L)

Unlike the outdated previous oil, this one is API SP/ILSAC GF-6.

See also related notes:

Hyundai/KIA Premium Gasoline Engine Oil SAE 5W-20 (API SL/ILSAC GF-3) (2023-04-13)

Image albums:

2023-11-23

Pentax K vs Sony FE/E caps

I was looking for caps (Sony FE/E mount side) for the adapters.

I had to try several options. This one fit well:

It turns out that a non-original Pentax K cap also fits:

It's funny.

Both types of caps:

See also related notes:

Крышки байонета Sony E (2022-04-17)

Image albums:

Lens accessories

2023-11-21

Canon G1400: Out of order

In 2017, I purchased the Canon G1400 printer. Unfortunately, it turned out to be a very disappointing model.

It worked fine for the first time, but then printing with black ink deteriorated dramatically. I had to print in "high resolution paper" mode, so that the black color is made by mixing C/M/Y colors.

The print heads often dried up, and it took a lot of ink to clean them.

Then misregistration (horizontal color misalignment/shift) occurred. Replacing the timing slit strip did not help.

Now the C/M/Y colors started to disappear, and cleaning did not help for long.

So I stopped using the printer altogether.

I think the G1400 is garbage compared to my previous Canon iP5000.

See also related notes:

Brother DCP-T220: My new printer (2023-12-29)

Image albums:

Printer

2023-11-19

Noname [OEM] 50/1.1 FF: Background blur (and Pentax K 50/1.4)

Comparison of background blur with the Noname [OEM ] 50/1.1 FF (center) and the Pentax K 50/1.4 (right) lenses on the Sony a7c (FF, 24MP) camera.

The scenes were changing because of the wind.

(Noname 50/1.1 at f/1.1, 1/8000)

(Noname 50/1.1 at f/1.4, 1/8000)

(Pentax 50/1.4 at f/1.4, 1/8000)

(Noname 50/1.1 at f/1.1, 1/8000)

(Noname 50/1.1 at f/1.4, 1/8000)

(Pentax 50/1.4 at f/1.4, 1/8000)

(Noname 50/1.1 at f/1.1, 1/4000)

(Noname 50/1.1 at f/1.5, 1/4000)

(Pentax 50/1.4 at f/1.4, 1/2500)

(Noname 50/1.1 at f/1.1, 1/8000)

(Noname 50/1.1 at f/1.5, 1/8000)

(Pentax 50/1.4 at f/1.4, 1/8000)

(Noname 50/1.1 at f/1.1, 1/1600)

(Noname 50/1.1 at f/1.5, 1/1600)

(Pentax 50/1.4 at f/1.4, , 1/1000)

(Noname 50/1.1 at f/1.1, 1/400)

(Noname 50/1.1 at f/1.4, 1/400)

(Pentax 50/1.4 at f/1.4, 1/320)

(Noname 50/1.1 at f/1.1, 1/3200)

(Noname 50/1.1 at f/1.4, 1/3200)

(Pentax 50/1.4 at f/1.4, 1/2000)

The Pentax has a wider field of view.

The background blur of the Noname lens is stronger and smoother (may look boring).

The f/1.1 aperture definitely has more light transmission than the f/1.4 on the Pentax.

The Noname's f/1.4 aperture still has more light transmission than the Pentax's f/1.4 aperture, but noticeably increases contrast and reduces flare (compared to the f/1.1 aperture).

See also related notes: