To HDR or not

I am experimenting with HDR images. There is probably fine line in the middle and I have yet to find it.


The image above is standard image

The image below is the HDR image


The HDR image looks surreal and almost dream-like.  The challenge in this image is the fact the sky is completely blown out and creates a massive backlight.  From an artistic point of view I enjoy working with the HDR version of the image but from a journalistic point of view I prefer the raw image.

I have an old bias, having been a photojournalist much earlier in my professional life I believe that photos should largely be untouched other than maybe adjusting the brightness and contrast similar to what we used to do in our dark rooms.

If I can learn to dial in the HDR tools a bit more I would lean towards using an HDR version of this image.

Canon T3i - first images

I took a couple of vacation days this week while the kids are on spring break. The boys and I decided to head out and try to capture a few pictures with the new camera.  It was kind of a tough day for photos: late winter gray with mostly overcast skies as another storm approaches.

The first image is a HDR image. I opened the Kisxx X4 RAW file and made three source images with at different brightness levels. I then loaded them into Qtpfsqui on my Ubuntu workstation to merge them into a single HDR image.


The car was a random sighting on MN12 between Litchfield and Willmar


BNSF 4343 near the end of the Marshall sub where it enters the Willmar yard.



BNSF 3128 as it enters Benson eastbound towards the Willmar yard.

Some better light would have been nice but frankly I was just happy to get outside for a little while and shoot some photos.

Canon T3i Raw + UFRaw (Ubuntu)

I recently bought a Canon T3i. I tend to shoot raw images (vs JPG).  I figured that I should validate that I can open the latest Kiss x4 Raw format on my Ubuntu machines prior to taking a short photo trip. Sure enough the new Kiss X4 format was newer than the plug-in that I use for GIMP.

After about 15 minutes of searching around for how to update UFRAW from 0.16 to  0.18 I stumbled across the following:

sudo add-apt-repository ppa:ferramroberto/ufraw
sudo apt-get update
sudo apt-get install ufraw gimp-ufraw

The notes were found at:
http://www.lffl.org/2011/02/ufraw-018-su-ubuntu-gnulinux-1010-1004.html#more

After updating the plug-in I am now able to load & edit the raw images.  Time to hit the road with the camera and see what we can find.

Pic + Si570 notes & ideas

I am compiling a list of ideas, notes, and links for people working with PICs and Si570 devices. I have some future projects that I am researching for when I have some homebrew time.

PicAxe + Si570 (some interesting notes on freeze & unfreeze)
http://www.dspradio.org/df7tv/src11


Si570 vfo with 16f628 and Si570
http://g4oep.110mb.com/si570vfo/570VFO.htm

Office Ideas

I have been working on the drywall in my new office in the basement. I am starting to see the light at the end of the tunnel. With the hope that I am nearing the completion of the drywall I am starting to think about the finishing touches for the new office.

One of those items is a new desk of some sort to try to efficiently utilize the same. As I was searching the Internet for "U" shaped desks I found a website that allows to put modular pieces together in a computer model. http://www.bush-furniture-online.com





















My new office will be an "L" shaped room.  Ideally I would like to put in a "U" shaped desk with three work surfaces. (Work computer, home computer, and the NG0R amateur radio station.)

I am also hoping to put in some sort of futon or small couch in the office. Since this will be a man cave eventually I would like put up a flat screen tv on the wall in the corner of the room.

I spent about 2 hours today modeling the room with different ideas and different sized objects. it is kind of funny to try to visual the room and the objects within the room (Yes, it is ubber geeky.)

73 de NG0R

Sunday activities

A busy Sunday here....

• I made a run for groceries with monster 1 & 2
• Spent some time chatting on 75m (3.740mhz) about filter design
• I spent about 90 minutes running filter models in the AADE software
• I spent a couple of hours taping the drywall in the new office/shack
• To end the day I am talking with the QRP folks on Echolink

It would be nice to think that I might able to move into the new office sometime this year!

73 de NG0R

Direct Conversion Receiver

I spent part of the afternoon messing with a Direct Conversion Receiver on a breadboard.  I experimented with with crystals, free running oscillators, and using a signal generator.



Audio Clip

I took the board over to N0FP's QTH and did some additional experimenting with it. We connected his signal generator to the board and a bandpass filter and spun the dial. The audio clip was captured with my DroidX phone recording the audio from the an amplified speaker.

It was interesting to adjust the LO drive compared to the RF drive level.

73 de NG0R

Modeling Filters with AADE software

I am looking to build some modular bandpass and lowpass filters for some projects.

Here is an example of a 40m Butterworth bandpass filter



I am using the AADE software for the modeling.

Goals:

• I would like to design some filters that use common value components.
• Bandpass
• Lowpass
• Make a small modular board with header pins
  

The idea is that you could plug the modular card into a breadboard or pcb with header pins. There are a lot of times when I am prototyping that I would like to have some filters on hand and a modular approach would be incredibly helpful.

So tonight I am spent a little bit of time bonding with the software looking at some design options and then comparing the part values with standard parts that are available at Mouser and/or Digikey.

Part of the magic is converting the parts to standard sizes and then rerunning the model to see if the parameters are still close enough that the design remains valid.

73 de NG0R

Direct Conversion on the workbench

I updated the breadboard from earlier today....


I hooked up the LM386 to the SA612, removed the 7.030 rock, and replaced the rock with the signal generator. I am now able to hear lots of signals from CW to Shortwave. Since I don't (yet) have a bandpass filter I am hearing a lot of spectrum.

Short Audio Clip  (The audio is rough, but there are only 13 parts on the breadboard.)

I will need to model some filters for the project. That might be the next experiment.

73 de NG0R

I am not completely crazy

I was frustrated yesterday as I was feeling beat down by a NE602/SA612. (That is pretty embarrassing.)

I am working on Direct Conversion Receiver projects at the work bench. (Kind of a baby step.)  Yesterday I had tried to wire up a SA612+LM386 and was getting nothing, nadda, big zero for audio. For what ever reason I was struggling to figure out why my SA612 was not working properly.

After running errands earlier today (Sunday) I got some free time late in the afternoon. I decided to put the SA612 on a fresh breadboard (I hate breadboarding) and start from scratch. The circuit is pretty simple.


It worked right away this time and I am not really sure why. It took about 5 minutes to wire up & attach the test gear. I had nice signals, good fundamental from the crystal, good RF from the signal generator, nice sum & difference products, and lots of harmonics.


The SBL1 is pretty darn easy to work with and the NE602/SA612 is not much more difficult.

When time permits I can move on the next phase of the experiment.

73 de NG0R