Showing posts with label creativity. Show all posts
Showing posts with label creativity. Show all posts

Saturday, March 16, 2019

Can Raspberry Pi boot from USB flash drive? And about how to do it guide.

Simple answer is 'yes, it can' but read on....
Or skip to the "So I will write summary first:" below.
Or skip to the "Raspberry Pi 3 B+ support USB boot.  How about Pi Zero W? Or other Pi?" below.


Not everyone is beginner, I think.

When people looking for how to guide for installing the OS(operating system), they were probably beginner or very first time trying to use Raspberry Pi. If that's the case, step by step guide might be very good choice.

But even so, it is better to explain general concept, I think.

If someone already knew some computer stuff, he or she probably doesn't need that step by step guide. Because Raspberry Pi is computer that means it is same concept.
For example, someone is Windows user like me and some Windows user knew if computer--motherboard support USB booting, Windows user can simply go to the CMOS setting and do boot from the USB stick.
So I'm thinking Raspberry Pi is computer so it might support USB boot, too.

So I'd like to know whether Raspberry Pi support USB boot or not. Or I might have to do something to get USB boot.
That's what I want to know, right?



So I will write summary first:


BCM2837-based Raspberry Pis which were all the Pi 3 models include compute module 3 and Pi 2 Model B v1.2, support USB host and Ethernet boot.

So if you have any of models with BCM2837, you can follow any general install OS guide (and install to the USB flash memory stick) which you might already knew.

And if you have other models include Pi Zero and Zero W, you need single file on your micro sd card and then it will boot from USB memory stick. So you can boot from USB memory stick and also need micro sd card with single file which I will explain below.



thought about boot from SD and then USB.

I am currently using the multiboot via berryboot.

And sometimes, I felt berryboot wasn't enough what I am trying to do. So I am thinking about like that.
3 or 4 OS on SD card and then 1 or 2 OS from USB flash memory.


So I was googling about it like this:
how do i install raspbian on usb memory


And I clicked below guide:

And read this part:
Important information
This tutorial is out-dated and has been updated here: ....
So I did clicked link which is below guide:

I have a Linux machine but most of my data--Raspberry Pi image file and etc, was on Windows which is my main computer.
So I clicked Windows version tutorial--below link.


I appreciate the detail guides. But when I am trying go through this guide it made me very confusing.
See this "Step 2 – Install Raspbian to the micro sd card"
And then "Note: If you’re using a Raspberry Pi 3+, you don’t need to do step 2. Jump straight to step 3."

"Step 3 – Install Raspbian to the USB Flash Drive"
The process is exactly the same as step 2, but this time we choose the USB flash drive as.....

And here--"If you're using a Raspberry Pi 3 Model B+, you can skip step 4."

"Step 4 – Prepare the Raspberry Pi for boot from USB"

"Step 5 – Boot Raspbian from USB Flash Drive"


Huh?
I realised that it is exactly same step as install Raspbian on micro sd card.

I have Raspberry Pi 3 B+ and Pi Zero W. So I already knew how to installing any OS on micro sd card.


As you can see, it took very long time to figure out.
Unfortunately, I clicked very old guide--May 2013. That probably is the reason though.



Raspberry Pi 3 B+ support USB boot. How about Pi Zero W? Or other Pi?

I am thinking newer Pi can support boot from USB memory stick but how about Raspberry Pi Zero W which I also have.

So I googling about it and found this:


This question already reveal how to do the booting from USB stick.

Quoted from the question.
The older Raspberry Pi's (Pi 1, Pi 2 and Pi Zero) couldn't boot from a USB-device, but the Raspberry Pi 3 has support for it. The Pi and Pi 2 have semi-support for it (using an SD-card with a single bootfile).

So if I wanted to boot from USB stick in Pi 1 and 2, I can place single bootfile--which I don't know it yet.

And other people answered that Pi Zero W use older chip like Pi 1 and 2.

And then I found someone wrote about that single bootfile--bootcode.bin.
And pointed to the source:
Special bootcode.bin-only boot mode section in Raspberry Pi boot modes - raspberrypi/documentation
Quoted from above link:
USB host and Ethernet boot can be performed by BCM2837-based Raspberry Pis (these are all Pi 3 models, and some Pi 2Bs). In addition, all Raspberry Pi models can use a new bootcode.bin-only method to enable USB host and Ethernet booting.

Just format an SD card as FAT32 and copy on the latest bootcode.bin.

This is useful for the Raspberry Pi 1, 2, and Zero models, which are based on the BCM2835 and BCM2836 devices, and in situations where a Pi 3 fails to boot (the latest bootcode.bin includes additional bugfixes for the Pi 3, compared to the boot code burned into the BCM2837).

If you have a problem with a mass storage device still not working even with this bootcode.bin, then please add a new file 'timeout' to the SD card. This should extend the time it waits for the mass storage device to initialise to six seconds.

I'm not 100% for sure yet. But if Raspberry Pi use BCM2837, USB host and Ethernet boot will support.

And I found all the Raspberry Pi specifications from Raspberry Pi - Wikipedia.
Screenshot of Wikipedia's Raspberry Pi Specifications section.
And as you can see, Pi 2 Model B v1.2 uses BCM2837. And all the Pi 3--3 Model A+, 3 Model B, B+ and Compute Model 3, lite, 3+.


So if you have Pi 2 Model B with v1.2, Pi 3 series and Compute Model 3 series, you can just install any OS on USB stick and remove micro SD card.

If you have other version include Pi Zero W, you can format the micro SD card and copy the bootcode.bin file.


Yes, I haven't tried it yet. But I think those are from the Raspberry Pi's official repository.
So I'm sure it will work.



Kali and Raspbian booted from USB flash drive.

I probably have to get more information about it so I just found this:
quoted from above link:
HawaiianPi wrote:
The Pi3 will check for a boot SD card first, before booting from a USB device. If no boot SD card is found in 5 seconds, then it looks for a boot USB device.

I think this is quite similar process as USB boot in PC--desktop and laptop computer.

When I read from above link, someone said some USB disk won't work. And I wasn't sure about it--If it's FAT32, why it shouldn't be.

But first I tried with quite old 8GB USB stick, it didn't work--Pi 3 B+ without micro SD card and Pi Zero W with single file on micro SD card.
So I thought I need to do something.

And I realised this could be compatibility issue. So I put my kind of new memory card read which can read SDXC format card, too.

Tada!


As you can see that micro sd card slot is empty.
Kali lite booted from USB Flash memory stick in Raspberry Pi 3 B+.
That USB memory stick doesn't work with USB boot--I tried like 2+ os and also with Pi Zero W.


This time, I tried same USB memory card reader with Pi Zero W. And it worked well.
And I had to put single file in micro sd card.
Raspbian stretch booted from USB Flash memory stick in Raspberry Pi Zero W.

If you'd like to connect more than two USB stick, portable hard disk or SSD, things became quite complicated. Because Raspberry Pi doesn't know which USB drive to boot from.

So you have to search more about it.


I hope you did learn about the basic concept or process of USB boot in Raspberry Pi.

Friday, March 15, 2019

Adafruit's Portable 5 inch Monitor with HDMI DIY looked interesting. But in reality....


I've seen this video: Portable HDMI Display for Raspberry Pi - YouTube

And I thought it looks very nice and quite useful because it isn't only for the Raspberry Pi--I can use as my DSLR monitor or game console monitor as well--I have a Nintendo NES classic edition which is kind of portable console.
So I'd like to do this....



It's expensive than I expected.

But when I saw inside of it, it shouldn't be easy to do.
Building the portable monitor won't be easy, for sure--I haven't done soldering before. But it requires a lot of parts to buy, too.

And if I do this, I might learn a lot of things about Adafruit, for sure.

So I visited building guide wep page.
Overview | Portable 5in Monitor with HDMI | Adafruit Learning System

And I realised I don't only spend a lot of time, I need a lot of money to building it, too.

  • 5.0" 800x480 TFT Display $29.95
  • TFP401 HDMI Breakout $24.95
  • FPC Extension Board $4.50
  • Powerboost 1000C $19.95
  • 2500mAh Battery $14.95
  • Slide Switch $0.95
  • Tripod Screw Insert $1.50
  • Total: $96.75

I thought this is too expensive for me. I need other things like print 3D case and lots of tools to do this.


So when I go through their guide, I saw that it can powering up the screen through USB.
That means, I can simply use my smartphone powerbank.
So no need to buy Powerboost 1000C and 2500mAh Battery.
And I don't have 3D printer so I don't need slide switch and tripod screw insert, too.

So I need three parts--5 inch display, TFP401 HDMI breakout, FPC extension board.
So total $59.4.



Cheaper or even better alternative--Aliexpress.

That means I don't need to do this.
Because I can simply buy from cheap Chinese store in Aliexpress, like this:
This is screenshot of 5 inch capacitive lcd display from Livetime Store in Aliexpress.
5 inch Raspberry Pi 3 Model B+ Touch Screen 800*480 Capacitive LCD Display + HDMI Cable + USB Cable + CD for Raspberry Pi 3-in Demo Board Accessories on Aliexpress.com

This is 5 inch capacitive touch display. And it costs $38--include free international shipping.
This model was different driver board design than 5 inch resistive display so I couldn't find case for this model.
5 inch resistive display case costs $6 to $10 in Aliexpress.
I can buy 5 inch display with case for about $48.

So it's much cheaper and better(include touch panel) than Adafruit's.
I know this because I just ordered one from there. So I search the a lot of similar--5 inch lcd.


If I wanted to learn about Adafruit, I probably can invest that much time and money.
But now I'd like to more focus on Raspberry Pi--and programming.

So I will buy 5 inch capacitive touch display.


You can also buy other 5 inch screen from Aliexpress like this:

This is the screenshot of '5 inch lcd hdmi' search result in Aliexpress.
Buy 5 inch lcd hdmi and get free shipping on AliExpress.com

This is the screenshot of '5 inch screen' search result in Aliexpress.
Buy 5 inch display and get free shipping on AliExpress.com

When you are searching the lcd screen, it doesn't show up many items. But you can find store that specialize in Raspberry Pi or SBC(single board computer). So you probably have to check Raspberry Pi store one by one.



It looks hard to build but maybe not that much.

At first, I don't think it's easy thing to do. When I saw this link:
On/Off Switch | Portable 5in Monitor with HDMI | Adafruit Learning System
It doesn't seem to easy, does it?
But if you are thinking about portable project, I think it's worth the effort.


I saw the next page. And if I learn about soldering, I think I can do this.
TFP401 Driver | Portable 5in Monitor with HDMI | Adafruit Learning System

And next,
Display | Portable 5in Monitor with HDMI | Adafruit Learning System
This part need just connect and position the cable. After that, screen is working.

Next part is mounting to the case.


Overall, if I learn and practicing soldering, it shouldn't be so hard.

But I still don't have a 3D printer and I don't like spend that much money.
So I will buy from Aliexpress.

Many of web store like adafruit, elements14, sparkfun, pimoroni were probably based on USA or UK so shipping and currency is too expensive to my country--Korea.
And same kind of store in Korea was all imported from those countries so things were much more expensive.

That's why Aliexpress is the best choice--for me. And probably to you, too.

Wednesday, July 18, 2018

Helios 44-2 58mm f/2 lens sample photos without pp.


quoted from Helios-44 | Camerapedia | FANDOM powered by Wikia
Helios-44 is a series of standard lenses for SLR cameras, produced in Soviet Union.... Based on the lens Biotar 2 / 58,....

So every version has slight different things like shorter(or longer) minimum focus distance, different aperture blades, etc.

This technical details were only for the Helios 44-2 version.


Helios 44-2 58mm f/2 lens technical details:

type: Prime lens
mount type: M42
optical design: 6 elements in 4 groups
aperture range: f/2 ~ f/16
aperture blade: 8
minimum focus: 50 cm
filter thread size: 49mm
weight: 230g
length: 57mm

I don't much care about this technical details of lens. But sometimes it can be useful.
For example, if I already have same uv filter or hood like this lens, I can use with this lens.
And I'm walking long hours when I do photo-walks. So if lens wasn't heavy, it was very suitable for me. That is the reason that I mostly shoot with prime lens.
So I do check those things from the technical details.


You can read more about the lens from here:



Here is comparison shots - Biotar vs Helios




Photos of the lens that I used:
Helios 44-2 58mm f/2 lens

Helios 44-2 58mm f/2 lens




Technical notes:

These photos were all taken with handheld and I used M42 lens to Sony E mount or Micro four thirds adapter so I have no idea about aperture number for the photo.

When I am taking photos, I do use Raw file format. So I need to convert raw file to jpg file and during that time, I do some post-processing--this is kind of darkroom process in developing film.
And when I do this, I don't use any default setting from Rawtherapee--open source software because there has some image modification settings like sharpening, micro-contrast and among other things.
I don't use Adobe Photoshop but this also has same kind of default setting with sharpening.
This isn't important for photography. But this is about the lens--what kind of photo I can take with this lens. So sharpening won't help to know about the lens.


So when I do use Rawtherapee, I removed all the default setting.
I will do these adajustments, if necessary:
 - click the auto button in exposure tab--automatically calculate the exposure value,
 - adjust exposure value, if overall image was still dark or too bright,
 - adjust contrast(between 3 and 18) in L*a*b* adjustments tab,
 - if there have some areas were too dark or too bright which makes me feel unbalance the overall look, adjust the shadow/highlight value.
 - Sometimes, white balance set to auto or slightly reduce the temperature value. Because Sony A7's white balance value was quite terrible when I do use other brand lens--not Sony E mount lens.




Sample photos:

Sony A7 full frame camera with Helios 44-2 58mm f/2 lens:

cherry blossom at Sincheondunchi - Helios 44-2 lens
cherry blossom at Sincheondunchi - Helios 44-2 lens
* It was my flickr account photo. Same post processing and then film simulation set to Kodak Ektar 100.

at the Sincheongyo, Daegu

forsythia at Sincheondunchi, Daegu

Cosmos sulphureus






Olympus E-P3 camera with Helios 44-2 58mm f/2 lens:

I didn't use Rawtherapee because I like the color of Olympus Viewer 3 produced.
I did only adjust exposure value. And then adjust level in Gimp--open source software.

at the Sincheondunchi, Daegu

I think it is morning glory or ipomoea kind of flower.

at the Sincheongyo, Daegu




P.S. If you'd like to read in Korean, you can read it from here--this is my Korean blog.

Friday, July 13, 2018

Pentacon 29mm f/2.8 MC M42 lens sample photos without pp.


Pentacon 29mm f/2.8 MC lens technical details:

type: Prime lens
mount type: M42
optical design: 7 elements in 7 groups
aperture range: f/2.8~f/22
aperture blade: 6
minimum focus: 25 cm
filter thread size: 55mm
weight: 210g
length: 53mm

I don't much care about this technical details of lens. But sometimes it can be useful.
For example, if I already have same uv filter or hood like this lens, I can use with this lens.
And I'm walking long hours when I do photo-walks. So if lens wasn't heavy, it was very suitable for me. That is the reason that I mostly shoot with prime lens.
So I do check those things from the technical details.


You can read more about the lens from here:



Technical notes:

These photos were all taken with handheld and I used M42 lens to Sony E mount or Micro four thirds adapter so I have no idea about aperture number for the photo.

When I am taking photos, I do use Raw file format. So I need to convert raw file to jpg file and during that time, I do some post-processing--this is kind of darkroom process in developing film.
And when I do this, I don't use any default setting from Rawtherapee--open source software because there has some image modification settings like sharpening, micro-contrast and among other things.
I don't use Adobe Photoshop but this also has same kind of default setting with sharpening.
This isn't important for photography. But this is about the lens--what kind of photo I can take with this lens. So sharpening won't help to know about the lens.


So when I do use Rawtherapee, I removed all the default setting.
I will do these adajustments, if necessary:
 - click the auto button in exposure tab--automatically calculate the exposure value,
 - adjust exposure value, if overall image was still dark or too bright,
 - adjust contrast(between 3 and 18) in L*a*b* adjustments tab,
 - if there have some areas were too dark or too bright which makes me feel unbalance the overall look, adjust the shadow/highlight value.
 - Sometimes, white balance set to auto or slightly reduce the temperature value. Because Sony A7's white balance value was quite terrible when I do use other brand lens--not Sony E mount lens.



I have two lenses. One with red MC and red letter on the feet. The other one is with green letter on the feet.
Photos of the lens that I used - Pentacon 29mm f/2.8 MC (green letter on the feet) lens:
Pentacon 29mm f/2.8 MC lens

Pentacon 29mm f/2.8 MC lens

Sample photos - Sony A7 full frame camera with Pentacon 29mm f/2.8 MC lens:

Rhododendron schlippenbachii - Pentacon 29mm's bubbly bokeh.
Pentacon 29mm's bubbly bokeh
* It was my flickr account photo. Same post processing and then film simulation set to Kodak Potra 160.

This is quite extreme bokeh, I think.
But you can also take photo like below--quite smooth bokeh:
I think it is morning glory or ipomoea kind of flower.

at the Sincheongyo, Daegu

Olympus E-P3 camera with Pentacon 29mm f/2.8 lens:
Pentacon 29mm's bubbly bokeh
I took this photo in jpg and use auto tone in Olympus Viewer 3 software.




Photos of the lens that I used - Pentacon 29mm f/2.8 (red) MC lens:
Pentacon 29mm f/2.8 red MC version lens

Pentacon 29mm f/2.8 red MC version lens


Sample photos - Sony A7 full frame camera with Pentacon 29mm f/2.8 red MC lens:

build up housing that quite long
at Taepyeong negeuri, Daegu
* It was my flickr account photo. Same post processing.

Sincheondunchi, near Dongsingyo

Sony Nex-5R camera with Pentacon 29mm f/2.8 red MC lens:


at the Sincheongyo, Daegu



P.S. If you'd like to read in Korean, you can read it from here--this is my Korean blog.

Sunday, July 1, 2018

Industar-50-2 50mm f/3.5 lens sample photos without pp.


Industar-50-2 50mm f/3.5 lens technical details:

type: Prime lens
mount type: M39, M42
optical design: 4 elements in 3 groups
aperture range: f/3.5~f/16, clickless
aperture blade: 6~8
minimum focus: 65 cm
filter thread size: 33.5mm, 35.5mm (rotating)
weight: 68g, 75g
length: 30mm

The Industar-50-2 50 mm f/ 3.5 (Russian: "Индустар") is a standard lens in Zenit (Зенит) camera.
And there was a version of Zorkiy (Зоркий) rangefinder camera.
FED Industar-10 50mm f/3.5 was copy(design was borrowed) from Leitz(Leica) Elmar lens--same collapsible style.
And Industar-50-2 was copy from(based on?) Tessar 50mm f/3.5's optical scheme.


I don't much care about this technical details of lens. But sometimes it can be useful.
For example, if I already have same uv filter or hood like this lens, I can use with this lens.
And I'm walking long hours when I do photo-walks. So if lens wasn't heavy, it was very suitable for me. That is the reason that I mostly shoot with prime lens.
So I do check those things from the technical details.


You can read more about the lens from here:





Here is photo of Industar-50-2 50mm f/3.5 lens with cameras:

Industar-50-2 50mm f/3.5 lens on Sony A7

Industar-50-2 50mm f/3.5 lens on Sony Nex-5R


Photos of the lens that I used.
Industar-50-2 50mm f3.5 lens
Industar-50-2 50mm f3.5 lens



This lens is very small so m42 lens to Nex(E mount) adapter is bigger like this:
Industar-50-2 50mm f/3.5 lens on m42 to nex adapter



Technical notes:

These photos were all taken with handheld and I used M42 lens to Sony E mount or Micro four thirds adapter so I have no idea about aperture number for the photo.

When I am taking photos, I do use Raw file format. So I need to convert raw file to jpg file and during that time, I do some post-processing--this is kind of darkroom process in developing film.
And when I do this, I don't use any default setting from Rawtherapee--open source software because there has some image modification settings like sharpening, micro-contrast and among other things.
I don't use Adobe Photoshop but this also has same kind of default setting with sharpening.
This isn't important for photography. But this is about the lens--what kind of photo I can take with this lens. So sharpening won't help to know about the lens.


So when I do use Rawtherapee, I removed all the default setting.
I will do these adajustments, if necessary:
 - click the auto button in exposure tab--automatically calculate the exposure value,
 - adjust exposure value, if overall image was still dark or too bright,
 - adjust contrast(between 3 and 18) in L*a*b* adjustments tab,
 - if there have some areas were too dark or too bright which makes me feel unbalance the overall look, adjust the shadow/highlight value.
 - Sometimes, white balance set to auto or slightly reduce the temperature value. Because Sony A7's white balance value was quite terrible when I do use other brand lens--not Sony E mount lens.



Old lens probably need increase contrast value:
This is very old lens--made since 1959. So my copy was very likely 1960's.

When I took the photo with this lens, scene looks quite smog-ish style. But after increased contrast, everything looks good.
This is quite common thing for old lens--I have many old lenses and most of them were like this. And it can easily fix.


Example photo:
ISO 1250 so I did use Imaging Edge software to post process - only increased exposure value to 0.5 ev and then white balance in 'auto'.
As you can see, color wasn't that strong.

After increased contrast--value to 15 in Gimp.




Sample photos:

Sony A7 full frame camera with Industar-50-2 50mm f/3.5 lens:

near Dongsingyo, Daegu

near Dongsingyo, Daegu

Sony Nex-5R body only

at the Sincheongyo, Daegu

Elmar 9cm f/4 lens, at the Sincheongyo, Daegu







P.S. If you'd like to read in Korean, you can read it from here--this is my Korean blog.

Friday, June 22, 2018

Sigma 30mm f/1.4 EX DC HSM lens sample photos without pp.


A few days ago, I wrote about this lens - Sigma 30mm f/1.4 Nikon mount APS-C lens on full frame camera--Sony A7 @ May 29, 2018
And I talked about second-hand price which was inexpensive. So I will quote that part:
Quite cheaper way to get the f/1.4 lens.

In Korea, secondhand Sigma 30mm f/1.4 EX DC HSM lens was not expensive--about $106 to $130 US dollars, especially Nikon mount. And others like Canon, Alpha mount were more--but not so much.
And secondhand Sigma 30mm f/1.4 for Sony E mount costs around $280.

Other cheap way to get the 1.4 lens is old lens like Takumar 50mm f1.4 or Nikon/Canon 50mm f1.4 which is slightly cheaper than Sigma.
But when put this lens on APS-C camera, it became 75mm lens. Because of crop factor.


According to the Sigma 30mm f/1.4 EX DC HSM lens - Wikipedia web page, on APS-C sensor cameras, its filed of view equivalent to a 46mm lens. Or slightly more for other camera like Canon, older Sigma bodies.



Sigma 30mm f/1.4 EX DC HSM lens technical details:

type: Prime lens
mount type: Canon EF-S, Micro four thrids, Nikon F (DX), Pentax KAF, Sigma SA, Sony/Minolta Alpha
optical design: 7 elements in 7 group
aperture range: f/1.4~f/16
aperture blade: 8
minimum focus: 40 cm
filter thread size: 62mm
weight: 430g
length: 59mm


I don't much care about this technical details of lens. But sometimes it can be useful.
For example, if I already have 62mm uv filter or hood, I can use with this lens.
And I'm walking long hours when I do photo-walks. So if lens wasn't heavy, it was very suitable for me. That is the reason that I mostly shoot with prime lens.
So I do check those things from the technical details.


You can read more about the lens from here:



Sigma 30mm f/1.4 lens with cameras:

Sigma 30mm f/1.4 lens on Nikon D7000
Sigma 30mm f/1.4 lens on Sony Nex-5R
Sigma 30mm f/1.4 lens on Olympus E-P3


Photos of the lens that I used.
Sigma 30mm f/1.4 EX DC HSM for Nikon mount lens
Sigma 30mm f/1.4 EX DC HSM for Nikon mount lens



Technical notes:

These photos were all taken with handheld and I used Nikon G lens to Sony E mount or Micro four thirds adapter so I have no idea about aperture number for the photo.

When I am taking photos, I do use Raw file format. So I need to convert raw file to jpg file and during that time, I do some post-processing--this is kind of darkroom process in developing film.
And when I do this, I don't use any default setting from Rawtherapee--open source software because there has some image modification settings like sharpening, micro-contrast and among other things.
I don't use Adobe Photoshop but this also has same kind of default setting with sharpening.
This isn't important for photography. But this is about the lens--what kind of photo I can take with this lens. So sharpening won't help to know about the lens.


So when I do use Rawtherapee, I removed all the default setting.
I will do these adajustments, if necessary:
 - click the auto button in exposure tab--automatically calculate the exposure value,
 - adjust exposure value, if overall image was still dark or too bright,
 - adjust contrast(between 3 and 18) in L*a*b* adjustments tab,
 - if there have some areas were too dark or too bright which makes me feel unbalance the overall look, adjust the shadow/highlight value.
 - Sometimes, white balance set to auto or slightly reduce the temperature value. Because Sony A7's white balance value was quite terrible when I do use other brand lens--not Sony E mount lens.



Sample photos:

Nikon D90 with Sigma 30mm f/1.4 EX DC HSM for Nikon mount lens:
at the Bongeunsa (sa means Buddhist temple)


Solution for auto focus problem in Nikon DSLR camera.
If you have a Nikon D90 or D7000 and problem with auto focus, you can probably fix with adjust 'Fine tune' in lens setting.
quoted from Autofocus is useless with Nikon D7000 body? | Sigma 30mm f/1.4 EX DC HSM | Flickr
einsteinsmonster said:
I had the same problem with my D7000.
Works perfect on D90.
Fine tuned the lens to -8 and now it's spot on.
Fine tune + or - till your happy with it.



Nex-5R with Sigma 30mm f/1.4 EX DC HSM for Nikon mount lens:

at Seongnae 2 dong--Bukseongro, Daegu
It was 45mm so slightly wider than 50mm. I felt quite wider than 50mm lens.

near Dongsingyo, Daegu
near Dongsingyo, Daegu
at the Sincheongyo, Daegu






Olympus E-P3 with Sigma 30mm f/1.4 EX DC HSM for Nikon mount lens - Olympus E-P3 has crop factor of x2 so lens became 60mm lens.

Magpies in a tree.
near Sinseonggyo, Daegu




at the Sincheongyo, Daegu




P.S. If you'd like to read in Korean, you can read it from here--this is my Korean blog.