June 2007 - Utah-Astronomy - mailman.xmission.com

iPhone commercial
by Chuck Hards 27 Jun '07

27 Jun '07

Has anyone noticed the name on the iPhone used in the TV commecial? "Erik Hansen"

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Glare through Telescope
by Kurt Fisher 26 Jun '07

26 Jun '07

Chuck said, > While there may be some substance to the software issue, I > think you've overanalyzed the situation, Kurt. > Most of the shots are just overexposed. Chuck, that's my point - they are overexposed but the question is whether there is any manual control of the exposure setting. For many of these small consumer hand-held digital cameras, there is no shutter speed or ISO control. You just tell the camera what type of scene you are looking at: daytime, indoors, etc. and its internal computer chip does all the settings automatically. (Humorously, the T10 has scene modes labeled "Pet" and "Food". Makes me wonder what kinda guy programmed this camera.) The problem is "Jupiter" or "the Moon" are not on its menu list and the camera will not figure out a correct exposure for solar system objects. But looking at a website listing the T10 options, it appears that the T10 may have both emulated shutter and ISO speed settings that can be manually set by the user. Scott wrote: > A co-worker today suggested to change the exposure, > which I didn't even think of. I don't know if that > is an option, so I'll have to learn the > camera a little better. That's the first step, Scott - learn how to set your exposure settings manually. Try the Moon at 400 ISO, increasing the shutter time up beginning around 1/200th of a second. Also experiment with the contrast setting - the "White balance" manual setting mode. That will help on the Moon, Venus, Jupiter and Saturn, all of which are currently above the horizon. It will not solve your problems with photographing a brush fire at night. See Chuck's prior comments on contrast limits. Scott asked: > As far as viewing different planets I've heard that > different filters will help get better pictures. The main filter to obtain first is an IR block filter. Digital cameras are oversensitive to near infra-red light. This overexposes dim objects with excessive red color. http://www.telescopes.com/products/celestron-uvir-cut-off-filter-1-25-inch-… Consider expanding into color planetary filters after you have mastered the basics. Here's a table of what color planetary filters do: http://members.csolutions.net/fisherka/astronote/plan/pcfilt/PlanetaryColor… Scott asked: > I'll I'm thinking of that, what do I need to do to view > the sun. I missed what type of telescope you are using. For white light solar viewing, you need a white light solar filter. Looking at the Sun or attaching your camera to a telescope and pointing it at the Sun will instantly blind you and literally fry the camera with smoke coming out the sides. A white light solar filter lets only about 1/100,000th of the Sun's light through, leaving a safe image to look at and to photograph. http://www.optcorp.com/ProductList.aspx?uid=471-307 For general tips on astrophotography, see Lodriguss's online guide: http://www.astropix.com/HTML/I_ASTROP/TOC_AP.HTM For futher help, probably the best thing you can do is to join a local astronomy club and come to a star party: either SLAS ( http://www.slas.us ) or if you are in Utah Valley, the Utah Valley Astro Assoc. ( http://www.uvaa.org/ ). - Kurt ====================== Attachment Some Optio T10 specs from a website: Metering TTL metering: Choice of Multi-segment metering Center Weighted Spot ISO sensitivity Auto ISO 80 ISO 160 ISO 320 ISO 400 Exposure compensation + /-2 EV 1/3 steps Shuttter speed 1/2000 to 4 secs Modes Program Scene modes Night Scene Voice recording Landscape Flower Portrait Surf & Snow Sport Pet Food Frame composition White balance Auto Daylight Shade Tungsten light Fluorescent light Manual setting _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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Glare through Telescope
by Kurt Fisher 26 Jun '07

26 Jun '07

Scott, As you try planetary exposures, these are generally done be experimenting with your camera settings to "bracket" the correct exposure of a particular scope, camera and planet. However, you will probably be wanting an initial guess for a first exposure setting. The following are three calculators that all implement Covington's exposure calculator from his "Astrophotography from Amateurs." The calculator will give an initial guess for solar system objects. http://www.rphotoz.com/astrophoto/expcalcs.html http://www.starizona.com/ccd/calc_ideal.htm http://www.covingtoninnovations.com/astro/astrosoft.html - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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Re: Venus attacks Saturn!
by Kurt Fisher 26 Jun '07

26 Jun '07

Running Venus and Saturn through Cartes du Ciel for a rough plot, I am showing Venus entering a 1 degree TFOV of Saturn on 6/29 at approx. 11:00 pm MDT local time. It remains within a 1 degree TFOV through 7/2 at sunrise. By the time of sunset on 7/2, local time, Venus will exited a 1 degree TFOV. - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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Glare through Telescope
by Kurt Fisher 26 Jun '07

26 Jun '07

Scott asked, > The pictures seem to be decent, but I find it hard to not get > glares from the light in the camera. For example, Venus for > the last few weeks has been visible and I can see it clearly > with my eyes through the telescope. But when I take a picture > it just glares. <snip> http://uwdh.com/beyondtheeyes/ Scott, It's probably the Pentax Optio T10 that you are using that causes the glare seen in the lunar and planetary images on your website. Pentax Optio T10 http://uwdh.com/beyondtheeyes/?page_id=23 This type of camera has lots of fuzzy logic built into it to optimize terresterial photographs of people and outdoor street scenes. That fuzzy logic also prevents the camera from dealing low light high contrast astrophotographic targets. Additionally, there probably is hardwiring that prevents it from being used for the relatively ultra-low light of planetary imaging. For the type of lunar and planetary images that you want to take, use a relatively inexpensive ($100) lunar planetary camera like a Meade LPI or a Celestron NexImage Solar System Imager. http://www.meade.com/autostar/lpi.html http://www.buytelescopes.com/product.asp?t=&pid=7769&m These astronomy cameras are built for lunar or planetary imaging only. They cannot be used on deep sky objects like galaxies. They are both USB-port devices that are plugged into a desktop or laptop computer. Their chip is similar to your Pentax Optio T10, but they do not have any hardwired blocks against low-light imaging. The software that comes with the camera also gives you better manual control over exposures. Correct exposure levels removes the glare. Adding a filter will not work. The fuzzy logic in the Optio T10 will just overcompensate for the filter. You are not seeing this glare problem in your excellent microscopy images, which I am guessing are also made using the T10. This is because you have enough control over the light to bathe the subject in high-intensity light giving medium contrast. Those light levels appear to be within the parameters of the Optio T10's fuzzy logic. - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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The sun at summer solstice
by WAYNE S CLARKE 25 Jun '07

25 Jun '07

Thank you Daniel and Kurt. Now I know. Wayne

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horizon distance between solstice sunrise points.
by daniel turner 25 Jun '07

25 Jun '07

Wayne: All you're missing is that the declination distance needs to be divided by the cosine of your latitude. 47deg / cos(41) = 62 degs. As for your not being very bright, I think you have asked a very intelligent question. That is is the mark of a mind that is growing and learning. DT ____________________________________________________________________________________ Got a little couch potato? Check out fun summer activities for kids. http://search.yahoo.com/search?fr=oni_on_mail&p=summer+activities+for+kids&…

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Glare through Telescope
by Scott A. Holdsworth 25 Jun '07

25 Jun '07

I have a question about taking pictures through a telescope. I have taken a few pictures of planets and the moon. Still learning about how to do it right. http://uwdh.com/beyondtheeyes/ The pictures seem to be decent, but I find it hard to not get glares from the light in the camera. For example, Venus for the last few weeks has been visible and I can see it clearly with my eyes through the telescope. But when I take a picture it just glares. Last night I observed this again with the fire on Lake Mountain (West of Utah Lake) from my home and I saw the same effect. Perfect with my eyes, but a lot of glare with the camera. What filter or other tool can I use to reduce the glare so my camera can capture the true picture? Also, what filters do I need for what objects in the sky? <http://www.uwdh.com/beyondtheeyes>

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Venus attacks Saturn!
by Kurt Fisher 25 Jun '07

25 Jun '07

In the sunset western sky, Venus and Saturn are about 3.8 degrees apart - sufficient for a telephoto lens wide-angle photograph. Venus 9h 23m 4s +16° 37.0' Saturn 9h 38m 17s +15° 26.3' Venus 09 23 04 +16 37 00 Saturn 09 38 17 +15 26 20 Angular distance: 3.8 degs on 6/25. This will decrease to within a single 1 deg eyepiece view on June 30. - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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RE: [Utah-astronomy] -8 is bright!
by Kurt Fisher 25 Jun '07

25 Jun '07

Chuck wrote: > You gotta love the Encyclopaedia Kurtannica. ;o) And I still haven't received your payment for volume L-O. -:) Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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