Monday, December 24, 2007

Mars 2007 opposition, second image

My second attempt for Mars imaging was near to 2007 opposition at 22nd December. Last time I did not succeed on imaging with my Barlow lens. Now I was able to get decent sized planet on the webcam sensor. There were not so many details on the side of Mars I have photographed, so more attempts are needed. I tried to focus as cafully as I could, with WO SCT focuser. There was no sharp focus point present. This may have been due to seeing effects. I had to battle a lot during imaging, to avaoid frost formation on the corrector lens. Good point to continue for next imaging round. Equiment used: Celestron C8 XLT, Televue 3x Barlow, SPC900NC. Image capturing and processing: VirtualDub, Registax v4 and Photoshop CS2.

Mars 2007 opposition, first light

Long time (over two weeks :-) after I got my C8 package, skies were finally clearing at Espoo. On the early morning hours of 13th December 2007, I carried my (damn heavy) equipment to near hill. First I did some visual tests of my scope, then finally pointed C8 to Mars. I got couple of raw video sequences. The planet size on the webcam sensor was way too small. Still some small details were revealed. I tried also to attach 3x Barlow lens, but I did not got video captured because of focusing problems (WO SCT focuser worked OK).

Thursday, December 6, 2007

SC OTA for planets, thoughts

Since the weather doesn't allow planet photography, I have plenty of time to consider what I need to invest in the near future to my C8 package:
  • Dew shield
Needed especially in cold winter nights. Normally the corrector lens will suffer from frost formation, just when the imaging session is ongoing... Flexible model would be more convenient, since my setup needs to be portable.
  • Magnifying finder
There was only a red dot finder (RDF) include in C8 (without base..., that was promised to be separately sent to me). Brightest planets will be visible through an RDF, but it may be a bit struggling to get planet directly in the field of small webcam sensor. This remains to be seen with the actual use of scope.
  • Heater strips
Combined with dewshield, heater strips will be another (and propably the best) solution to battle against corrector lens frost. If/when I get more seriously interested about visual use of my scope, I may need to buy heater strip for eyepieces also.

Tuesday, December 4, 2007

SC OTA for planets, scope arrived

The C8 XLT scope arrived, at 30th November 2007. I wasn't home, when first delivery was attempted by UPS, so scope had to picked up at local UPS storage premises. This is how my planet imaging setup looks like:

System consists of Celestron C8 XLT Schmidt-Cassegrain scope (2032mm, f/10), mounted on Skywatcher HEQ-5. There is enough of focal length in C8 to be used for planet imaging. In case I later on get interested in DS photography, this tube will come in handy with some focal reducer - like 0.5x -model from Optec.

I have bought a separate Grayford focuser from William Optics. This way you can get a smoother focusing, and also both 1.25" and 2" accessory connections. Focuser also rotates around it's axis, to allow suitable composition in the image.

3X barlox is from Televue, quality and build looks and feels very convincing. Barlow lens felt solid, and a bit heavy when I first took it in my hand. I believe it will be worth of invesment. Reflections in the lens surfaces were very deep green, so I assume lens coatings are typical (and good) Televue value.

AVI sequence of the planets will be captured with Philips web camera. SPC900NC was available at the time. Oririginal lens was removed from camera and 1.25" adapter was screwed into lens thread. I also use a Baader UV/IR cut filter in front of the sensor, to ensure better image quality.

All I need now is some freetime and clear skies with good seeing. Currently it does not look too promising... Sleet is pouring down from the sky.

Sunday, November 25, 2007

Samsung SHC-721A, IR testing

This video surveillance camera has a black & white mode. Usually it is meant for low-light conditions. According to manual, there's not clearly defined what happens in this mode. When lens is removed - in front of the CCD sensor - there is visible some filter foil. That has light green/cyan color. When BW mode is activated, a short "bzzztt" sound is heard. I assume that camera moves the filter away from top of sensor.

I decided to make some experimental testing, to see whether this camera was sensitive to IR. The target was hot soldering iron (Weller WTCP-s). The temparature in the solder tip is approximately +300°C. The equipment setup was:

Samsung SCH-721A camera
Nikon F / C-mount adapter
MF Nikkor 55/2.8 macro lens

results were recorded video clips:
1st, normal room lightning
2nd, very low light level
3rd, no room lightning

There is no IR sensitivity visible on 1st video clip. On the second video, IR radiation is clearly visible (brighter spot during heat-up cycle). This also shows the position of heating element inside of the solder tip. Third image shows the IR only, because there is not room lightning used. I was just wondering, where could I actually use this for. Has the sun some activity on the IR...? It remains to be seen, where this particular sensitivity is suitable for.

Wednesday, November 21, 2007

SC OTA for planets, order status

Order process is ongoing, but not so fluently as I expected. All the needed parts arrived to dealer. That had been informed to me already, my e-mail safety rules had blocked this mail. Payment is now done. Currently I am waiting for the dealer in Germany to inform me, when payment is received at their side. I was told that I will receive UPS tracking number, when shipment is done. I would estimate that scope arrives somewhere on the end of next week, hopefully...

Comet 17P/Holmes

This is my first decent comet image I've produced with Nikon D200. I'm quite satisfied with the result, this a good point to develop skills further. 17P/Comet was imaged at Nuuksio nature park, on 4th Novenber 2007. Size was approximately 1/3 of full moon diameter. Image is made up of 21 separate frames, each 30sec @ISO800 with 300/4.5 MF Nikkor lens.

Saturday, November 3, 2007

Comet 17P/Holmes

On the 1st November 2007, I tried again to photograph this comet. Locally it was too windy, and D200/MF Nikkor 300f4.5 would have been affected by shaking. Visually the target was like few days before. The next attempt will be most propably on Sunday 4th November. For that night my work colleague planned an observation session to near nature park at Nuuksio.

Thursday, November 1, 2007

Comet 17P/Holmes

Yesterday I had a possibility to view a this magnificent comet on Espoo sky, with my 15*70 Helios -binoculars. What a beatiful sight! I have seen many pictures at web, but now I finally realized the actual size of it. It looked like a large fuzzy plate in the sky. The inner part of the comet was bright. Around the core thre was a bit darker rim. Towards the edge of comet, brightness inscreased slightly.

With my naked eye observation, the comet looked as small fuzzy dot. It was cleary diffrent than the bright stars. Sometimes it looked, that I was able see the bright core, not still 100% sure of it. Later on the evening / night the sky was cloudy, so I didn't had opportunity to photograph it. Later on today I'll make new attempts, the weather forecast looks promising.

Monday, October 22, 2007

Sun without spots

My first decent attempt to photograph the sun... This time it did not have any visible spots, image was taken at 20th October 2007. Used equipment were: Baader solar filter foil, Nikon 300/4,5 tele lens and Samsung SHC-721A surveillance camera. This final image was stacked from separate frames with Registax, approximately 250 frames were used.
After taking the original AVI clips, some problems were really visible. Below is one frame captured from the clip. Below and above the sun, the brighter area is visible. This may be due to blooming affect on the camera. Also narrow darker vertical "stripes" are visible. This particular camera has menu, but I have not found any blooming related adjustments there. Looks like this type of camera is not very suitable for high contrast targets...

Wednesday, October 17, 2007

SC OTA for planets, order placed

Today I have placed an order of SC OTA, to be used for planet photography mainly. I would expect, that there is good package for many years to come:

Celestron C8 OTA with XLT coatings
William Optics SC Grayford focuser
TeleVue 3x barlow (1.25" size)

Now I have couple of weeks and endless hours of waiting the package to arrive. Just like a small child waiting for the Santa Claus to visit :-)

Wednesday, October 3, 2007

Nikon EH-6 secrets, part1

Opening the covers of the EH-6 power supply, exposes parts with high voltage. So there is actual risk of electric shock, dangerous to your health. I have checked information in this article. I do not take any responsibility of the actual information, the correctness of information, or misusage of it. If you have any feedback, please inform me.

This "cracking project" started when I bought a external power supply for my Nikon D200 camera. The only available model was the EH-6 supply (by Nikon, that propably explains the price tag). For astro photography there also was a need to use D200 directly from the "non-Nikon" DC supply. The current / voltage specs needed for that were same as in EH-6, i.e. 13.5V 5A. Also there was a need to know pin purpose for low voltage connector (that mates the D200 body).

So I decided to "sacrifice" my EH-6 product quarantee, and open the covers... There was most propably SMPS -type power supply inside (based on the small size of heat sink and the high voltage electrolytic capacitor). On the left side, low voltage output cable connects to Nikon D200 (red / black wires).

I measured the DC voltage on the output. It was 13.66V, when supply was not connected to D200. After connecting supply to camera and swithing on it, the voltage dropped to 13.65V. Red wire carries the positive voltage (I call it as "VCC") and black wire is for the ground connection ("GND"). After measuring the voltages on the secondary side of EH-6 supply, it looks that pins have following purpose:

The "NC" stands for "not connected". This is because I did not found any voltage on this pin. I measured the resistance also towards the other pins, no connection found. If this "NC" pin has some other purpose, that I do not know (if you have info, please let me know). The respective pins on the Nikon D200 body are:

Again the "NC" pin was named on the D200 body. This is a pin that I am not sure, where is used to (if you have info, please let me know). The following is a situation where I feed D200 power from the external adjustable DC supply. Voltage reading (13.58V) is on the upper left, and current (0.29A) on the right. Typically the camera drains 0.3A, when swithed on and back TFT display is on. During long "bulb" exposures, the drawn current was about 0.6A. This is two times the "average" value. Current drain is especially important factor (if the camera is used only by batteries)

What I will do with my EH-6 supply ? For the moment, I'll leave it like it was. If I am not able to find the Nikon specific power supply connector electronics stores, I propably need to cut the secondary wire in half. And to install some suitable good quality two-pole locking connector there inbetween. That would allow to use EH-6 and leave also possibility to power D200 with suitable "non-Nikon" DC-supply.