Start - Borbin the 🐱

Selling Lenses 🛒

📅 19. April 2025 · Fotografie · ⏱️ 2 min

Selling lenses (and 📷) is easy. At least according to the offers from small and large camera dealers. Advertising with 'up to 70% of retail' should have the focus on 'up to'.

Here is my result: Quotes from camera sites and then selling at eBay at the average eBay price.
If the value is 0, they did not want the lens.

	B&H	Glazer's	Kenmore	MBP	eBay
Nikon AI-S 28-85 f/3.5-4.5	125	35	30	0	95

Nikon AI-S 28-85 f/3.5-4.5	125	35	30	0	95

Nikon 35-105mm f/3.5-4.5 AI-S	25	15	15	28	145

Nikon AI-S 70-210mm f/4.5-5.6	30	15	10	0	95

Nikon AF 105mm f/2.8 D Macro	75	72	100	118	185

Nikon 55-200mm f/4-5.6G ED VR II AF-S D	50	27	10	42	115

Nikon 55-200mm f/4-5.6G ED VR II AF-S D	50	27	10	42	115

Sigma 30mm f/1.4 DC HSM	70	52	50	72	185

Sigma 50mm f/2.8 DG Macro	75	0	30	128	165

Sigma 50-150mm f/2.8 EX DC APO HSM	0	125	115	121	385

Tokina 500mm f/8.0 Mirror Lens for Nikon	0	0	35	125	165

Ʃ	625	403	435	676	1745


Sigma 8mm f/3.5 EX DG Fisheye	140	50	125	87

Nikon AF 50mm f1.4D	75	42	65	55

The quote from Adorama required to send in the lenses, but I was told the estimate would be around 500.
B&H's is similiar price, but there is an exception for the Nikon AI-S 28-85 f/3.5-4.5. Seems like a very sought-after lens, but not for MBP.
So far, B&H pays best for those (vintage) lenses.

The last two lenses I decided to keep, but I had them added to the quote to check. Would you sell for this price?

Update:

Lenses have been sold on eBay, with an approximate 20-25% fee deducted. The only exceptions are the two Nikon AI-S 28-85mm f/3.5-4.5, which I traded to B&H for a tax-free voucher. They are still listed for sale there¹, quietly gathering digital dust.
The lens shelf now looks more intentional and less like a clearance bin.

Both lenses were in like-new condition and nearly indistinguishable from each other, yet they are listed with noticeably different condition ratings and prices. So much for consistency in evaluations. ↩

Montlake Bridge

📅 14. April 2025 · ⏱️ 2 min

I often pass the Montlake Bridge on my way to UW, but today was different: the bridge opened for water traffic just as I got there. The light turned red, and the bars descended, signaling the bridge's closure. I watched as the bridge slowly lifted to allow a sailboat to pass through, but I only saw the sailboat's mast passing by. Remarkable to see the massive structure rise and then descend back into place.

14:00:56, Bridge starting to open

14:01:36

14:01:52

14:02:06

14:02:36

14:03:06, Bridge fully opened

14:04:52, Bridge closing

14:05:08

14:05:50, Bridge completed its cycle and traffic resumes in a few seconds

A few days later, I was on the other side of the canal while traffic stood still, watching the bridge rise and settle once more.

A few months later, I was first in line on that same route with a perfect view as the bridge began its cycle. The timing could not have been better. The red lights flashed, the gates descended, and the massive structure started its graceful ascent. Positioned at the very front, I could see every detail: the roadway lifting, the two halves opening, and the quiet pause at full height before the bridge eased back into place.

A while later, I checked the traffic and noticed the red lines of waiting cars on the map. Sure enough, the bridge was operating. Here are some screenshots from a different perspective:

Gates open

Traffic resumes

Bellevue Downtown Park

📅 14. April 2025 · Panorama · ⏱️ 1 min

Sunny Sunday afternoon at the Bellevue Downtown Park.

Interactive Panorama Bellevue Downtown Park 1

1/800s f/5,6 ISO 100/21° f=7,5mm

Interactive Panorama Bellevue Downtown Park 2

1/800s f/5,6 ISO 100/21° f=7,5mm

Lake 1

1/400s f/7,1 ISO 100/21° 16-50mm f/3,5-6,3 VR f=16mm/24mm

Lake 2

1/1000s f/5,6 ISO 100/21° f=7,5mm

Lake 3

1/400s f/7,1 ISO 100/21° 16-50mm f/3,5-6,3 VR f=16mm/24mm

Downtown View

1/400s f/7,1 ISO 100/21° 16-50mm f/3,5-6,3 VR f=24mm/36mm

Duck's corner

Fisheye lens captures the corner of the waterfall, a favorite haunt for 🦆

1/800s f/5,6 ISO 100/21° f=7,5mm

Different projections:
[Cylindric] [Equirectangular] [Mercator] [Rectangular] [Vedutsimo]

Backup your pictures 💾

📅 11. April 2025 · Fotografie · ⏱️ 6 min

Backing Up a NAS via SSH and rsync

A practical guide to safely backing up large NAS file sets via SSH and rsync, including why some external USB hard drives slow down dramatically due to SMR technology.

NAS (Network Attached Storage) is a convenient solution for storing pictures, videos, and all your other files. The NAS device is typically configured as RAID-1, utilizing two disks so the system can continue operating if one disk fails, thereby improving availability. It connects to your local network, providing reliable and accessible storage, but it is not a backup.

Backing up files from a NAS device is very important to ensure data integrity and availability.
Many NAS systems, such as my Synology NAS, come equipped with backup software like Hyper-Backup. Unfortunately, this software tends to become slower over time during long backup runs, especially with very large file sets.

Using PuTTY, a popular SSH client, and simple Linux commands, you can efficiently perform backups and verify them directly on the NAS. Here is a step-by-step guide.

Prerequisite

NAS devices typically feature USB ports, allowing you to connect an external hard drive of the required size directly to the NAS via USB. External drives are available in two main types: SSD (Solid State Drives) and HDD (Hard Disk Drives with spinning disks). I am using HDDs because of their long-term data retention capabilities, but SSDs are faster and maybe perfect for frequent short term backups.

The drive connects to the system with a path like /volumeUSB1/usbshare. Simply check with the cd and dir command.
On Synology systems, user data is typically located under /volume1, which will be used as the source path in the following examples.

I recommend formatting the drive with NTFS. On large volumes, exFAT often uses very large allocation units, which can waste significant space when storing many small files.

Note on SMR-based external hard drives

Many modern 2.5" external USB hard drives use Shingled Magnetic Recording (SMR). With SMR, write performance may appear fast at first, because new data is written into a small sequential write area. Once this area fills up, the drive must internally reorganize and rewrite entire zones to place the data permanently. This consolidation happens in the background and can take a long time, during which the drive remains busy and write speeds drop significantly.

This behavior is a direct consequence of how SMR works. SMR increases storage density by partially overlapping adjacent magnetic tracks, similar to roof shingles. Because the write head is wider than the read head, writing a new track overwrites part of the previous one, which prevents individual tracks from being updated independently. To manage this, SMR drives group tracks into zones that are written sequentially. Updating existing data requires a read-modify-rewrite cycle of the full zone, which is handled entirely by the drive firmware in drive-managed SMR and is invisible to the operating system.

As a result, long periods of drive activity and reduced sustained write performance are expected with fragmented or many-file workloads. This behavior affects performance, not data integrity, and does not indicate failing hardware or reduced long-term backup safety.

Step 1: Connect to your NAS using PuTTY

Download and Install PuTTY.
Open PuTTY and enter the IP address of your NAS in the "Host Name (or IP address)" field. Default Port is 22.

Login: Click "Open" and log in using your NAS credentials. You should now have access to the NAS embedded Linux console.

Step 2: Backup Files using the `rsync` command

The rsync command of the embedded Linux system of the NAS is used to copy files and directories.
To backup files from your NAS to another drive, follow these steps:

Navigate to the Source Directory:

cd /volume1

For large data sets, the copy process can take several days, and the PuTTY terminal may disconnect, closing the command. To prevent this, use the nohup command to keep the process running even if the terminal disconnects.

While commands like screen or tmux can be used to detach from the current terminal session, they are not always available on every system. At least, it is not available on the Synology NAS.

Copy Files to the Backup Location using rsync command with nohup. The rsync command has a visual progress and is a better choice for very large archives than the cp cmd.

Copy folders 2023, 2024, 2025 and "folder with spaces" to the backup folder "Bilder":

nohup rsync -rltD -W --info=progress2 --no-owner --no-group --no-perms --no-times --no-inc-recursive 2023 2024 2025 "folder with spaces" /volumeUSB1/usbshare/Bilder/ &

Note that source directories are specified without a trailing slash so that rsync creates the corresponding directories on the backup drive. Using a trailing slash on the source directory would copy only the contents of the folder and place all files directly into the target directory, flattening the structure. Always verify source and target paths before starting large copy operations.

The nohup command immediately returns and provides a process ID (PID). You can use the ps or htop command to check for this PID if it is still running in later sessions. Use the kill command with this PID to stop the backup.

Use iostat -x 1 to observe disk activity. When running under nohup, progress output can be viewed using cat nohup.out.

For large archives and long-running backups, rsync typically provides better robustness and verification than simple copy commands.

Step 3: Verify the Backup

After the backup has completed, it is important to verify that all files were copied successfully.

A practical and efficient way to do this is to run rsync in dry-run mode. This compares the source and destination and reports which files would still need to be copied, without making any changes:

rsync -rltD --dry-run --ignore-existing /volume1/Archive/Bilder/ /volumeUSB1/usbshare/Bilder/

ℹ️ --ignore-existing ensures that rsync only reports what would be missing, without copying anything again.
ℹ️ --dry-run makes no changes.
ℹ️ This comparison checks file presence and timestamps, which is sufficient for most photo archives.

For very large file sets, use nohup so the verification is not interrupted by a disconnected terminal session:

nohup rsync -rltD --dry-run --ignore-existing Bilder/ /volumeUSB1/usbshare/Bilder/ >verify.log 2>&1 &

Additional quick sanity checks include comparing the number of files and the total size of both directories:

find Bilder -type f | wc -l find /volumeUSB1/usbshare/Bilder -type f | wc -l

du -sb /volume1/Archive/Bilder du -sb /volumeUSB1/usbshare/Bilder

Small differences in reported size are normal, but large deviations should be investigated.

Finally, for a strict and exhaustive comparison, the diff command can be used:

diff -qr /volume1/Archive/Bilder /volumeUSB1/usbshare/Bilder

This performs a recursive comparison of the directory trees and may take a long time on large archives. For long-running checks, use nohup and redirect the output to a file for later inspection.

My first digital camera was a Kodak DC-260, and I used 3.5" 💾 for backup.