Tuesday, November 28, 2017
Part of Winter Hexagon
The area of Gemini and Auriga are part of the winter hexagon and have some interesting open clusters like M35, M36, M37, M38 and M44. The picture is not that good but it gives a nice overview.
Sunday, November 26, 2017
Photokina 2018 : Block Your Agenda
Photokina is the world’s leading trade fair for the photo, video and imaging sectors. More extensive than any other event in the world. And you can join next year 2018 from September 26-29 in Cologne (Koln-Germany).
The year after, in 2019, the trade fair will be again organised. This time in May which will be start of an annual cycle.
Perfect Observation Sites in the BeNeLux
The Deep Sky Group from the VVS provides the best observation locations in the BeNeLux. - see this link.
Electromagnetic Spectrum of the Sun : Microwaves Part 1
Can we observe the entire electromagnetic spectrum of the Sun on Earth? The answer is no. Once the radiation penetrates through Earths atmosphere some are reflected, absorbed or scattered. This is shown in below graph provide by NASA.
The common electromagnetic radiation from the Sun observed on Earth are visible light, microwaves and radio waves. Microwaves are defined as waves with wavelenghts between 1m and 1mm and thus a frequency between 300MHz en 300GHz. This is calculated via
wavelength (m) = phase speed (m/s) / frequency (Hz) (Phase speed in space equals speed of light)
In a next article I will explain the correlation between Sunspot data and microwaves emitted from the Sun.
The common electromagnetic radiation from the Sun observed on Earth are visible light, microwaves and radio waves. Microwaves are defined as waves with wavelenghts between 1m and 1mm and thus a frequency between 300MHz en 300GHz. This is calculated via
wavelength (m) = phase speed (m/s) / frequency (Hz) (Phase speed in space equals speed of light)
In a next article I will explain the correlation between Sunspot data and microwaves emitted from the Sun.
Buying Guide Best Cameras : Nikon D7500
DPReview provided their 2017 list of Best Cameras by Use case and by Price Case.
My Nikon D7500 is picked
- as Best Camera in the category "by Price Case under $1500".
- as Third Best Camera in the category "for parents"
- as Fifth Best Camera in the catergory "for Sports and Actions"
My Nikon D7500 is picked
- as Best Camera in the category "by Price Case under $1500".
- as Third Best Camera in the category "for parents"
- as Fifth Best Camera in the catergory "for Sports and Actions"
This is the feedback from DPReview :
Nikon D7500 20.9MP APS-C CMOS Sensor | 51-point AF system | 3.2" tilting touch LCD
What we like:
Excellent image quality
Deep buffer and fast burst rate
Impressive AF subject tracking through the viewfinder
Small and light for a DSLR in this class
What we don't like:
Crop factor limits lens choices when capturing 4K video
Snapbridge Wi-Fi system needs improvement
Mediocre video autofocus
The Nikon D7500 is a capable and refined DSLR that produces excellent quality photos from its 20.9 megapixel CMOS sensor and also offers an impressive buffer and reliable autofocus system.
For a twin dial DSLR, it is relatively compact, but is definitely larger than most mirrorless competitors. It has a deeper grip than its predecessor, as well as improved weather-sealing. The flip-out touchscreen is responsive and can be used for focusing, menu navigation or image playback. The optical viewfinder is well-sized and has an eye sensor that turns off the LCD when you're using it.
Autofocus performance from the 51-point AF system is also quite good. The camera subject tracks with impressive accuracy thanks to its 180k-pixel RGB metering sensor. An 8 fps burst rate, coupled with a buffer depth of 50 Raw or 100+ JPEGs, means the D7500 is well-prepared for sports or action.
The camera also tracks with impressive accuracy thanks to its 180k-pixel RGB metering sensor.
Image quality from the D7500 is excellent. JPEG color tends to be pleasing, and noise reduction at high ISOs tends to be well balanced. Raw image quality is exceptional, in terms of both dynamic range and low light noise.
The D7500 can shoot 4K/UHD video but with a 1.5x crop factor (on top of the existing 1.5x APS-C crop factor), which can be pretty limiting. The quality of the 4K footage is competitive, though. The camera is also capable of Full HD video capture at up to 60 fps. Auto ISO can be used during capture and the camera has a built-in mic jack (no headphone). Autofocus during video capture is not very useful, since it's noisy, jumpy and occasionally hunts for focus.
If you're in the market for a DSLR under $1500, the D7500 is strong choice. As one of Nikon's enthusiast-grade APS-C cameras, it offers plenty of controls, customization and impressive performance that should satisfy the most demanding of stills shooters. While it can shoot 4K video, there are plenty of cameras that do so with better autofocus and no crop factor. At the end of the day, for a stills-focused photographer the D7500 an excellent camera - and one that can make use of a vast range of Nikon and third-party lenses going back decades.
Nikon D7500 20.9MP APS-C CMOS Sensor | 51-point AF system | 3.2" tilting touch LCD
What we like:
Excellent image quality
Deep buffer and fast burst rate
Impressive AF subject tracking through the viewfinder
Small and light for a DSLR in this class
What we don't like:
Crop factor limits lens choices when capturing 4K video
Snapbridge Wi-Fi system needs improvement
Mediocre video autofocus
The Nikon D7500 is a capable and refined DSLR that produces excellent quality photos from its 20.9 megapixel CMOS sensor and also offers an impressive buffer and reliable autofocus system.
For a twin dial DSLR, it is relatively compact, but is definitely larger than most mirrorless competitors. It has a deeper grip than its predecessor, as well as improved weather-sealing. The flip-out touchscreen is responsive and can be used for focusing, menu navigation or image playback. The optical viewfinder is well-sized and has an eye sensor that turns off the LCD when you're using it.
Autofocus performance from the 51-point AF system is also quite good. The camera subject tracks with impressive accuracy thanks to its 180k-pixel RGB metering sensor. An 8 fps burst rate, coupled with a buffer depth of 50 Raw or 100+ JPEGs, means the D7500 is well-prepared for sports or action.
The camera also tracks with impressive accuracy thanks to its 180k-pixel RGB metering sensor.
Image quality from the D7500 is excellent. JPEG color tends to be pleasing, and noise reduction at high ISOs tends to be well balanced. Raw image quality is exceptional, in terms of both dynamic range and low light noise.
The D7500 can shoot 4K/UHD video but with a 1.5x crop factor (on top of the existing 1.5x APS-C crop factor), which can be pretty limiting. The quality of the 4K footage is competitive, though. The camera is also capable of Full HD video capture at up to 60 fps. Auto ISO can be used during capture and the camera has a built-in mic jack (no headphone). Autofocus during video capture is not very useful, since it's noisy, jumpy and occasionally hunts for focus.
If you're in the market for a DSLR under $1500, the D7500 is strong choice. As one of Nikon's enthusiast-grade APS-C cameras, it offers plenty of controls, customization and impressive performance that should satisfy the most demanding of stills shooters. While it can shoot 4K video, there are plenty of cameras that do so with better autofocus and no crop factor. At the end of the day, for a stills-focused photographer the D7500 an excellent camera - and one that can make use of a vast range of Nikon and third-party lenses going back decades.
Saturday, November 25, 2017
Less then a month to go
On december 21 it's again time to set up for your next solargraph. So you have 4 weeks to prepare making your own pinhole camera. DIY Instruction are available via my blog link here.
I will be preparing my next ones as well ... :) and it's not about the beer... it's about the 50cl cans.
On december 21, I will remove my installed pinhole camera's which are out since June 21. It will be my first results of the period June-December. All my previous Solargraph are made in the period Dec-June. I'm curious about the result and what would be the difference between the periods.
I will be preparing my next ones as well ... :) and it's not about the beer... it's about the 50cl cans.
On december 21, I will remove my installed pinhole camera's which are out since June 21. It will be my first results of the period June-December. All my previous Solargraph are made in the period Dec-June. I'm curious about the result and what would be the difference between the periods.
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| Pinhole Camera Installed Since June - Size of the can 71Cl |
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| Pinhole Camere installad since June - Size 50Cl |
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