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
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. Similar exposures can be made with just about any chip, or emulsions. Before Scott tosses the Pentax, I am sure he can get much better exposures with a few adjustments. A glare shield may help the twilight lunar shots, and a check for clean optics. The terrestrial night shot of the fire, for instance, is simply a contrast issue due to overexposure. Some judicious photoshopping would help, as well. Don't discard the Pentax just yet, Scott. On 6/25/07, Kurt Fisher <fisherka@csolutions.net> wrote:
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.
After getting the telescope I realized I wanted to capture the images I found. I looked at the options of an imager or a webcam, but thought the Optio T10 (6 MegaPixel) would be higher quality. Plus, I really enjoy using the camera. The touchscreen makes it easy to control once it is attached to the telescope. So I found an adapter which is working pretty good. 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. As far as viewing different planets I've heard that different filters will help get better pictures. Anyone have a chart that says what is good for what? I'll I'm thinking of that, what do I need to do to view the sun. Do I need a completely different telescope? Thanks for all your help. -Scott A. Holdsworth On 6/25/07, Chuck Hards <chuck.hards@gmail.com> wrote:
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. Similar exposures can be made with just about any chip, or emulsions. Before Scott tosses the Pentax, I am sure he can get much better exposures with a few adjustments. A glare shield may help the twilight lunar shots, and a check for clean optics. The terrestrial night shot of the fire, for instance, is simply a contrast issue due to overexposure. Some judicious photoshopping would help, as well.
Don't discard the Pentax just yet, Scott.
On 6/25/07, Kurt Fisher <fisherka@csolutions.net> wrote:
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.
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You can use filters to bring out certain types of features. In my experience, the detail that became visible was rough detail. The fine stuff along the edges of Jupiter's cloud bands was lost when filtered. There are many web pages with lists of what the filters will help you see. I just did a Google on filters planets and it came up with a bunch of pages. I have included two links that came from that list but there were many more. One more thing to consider about filters is their quality. A poor quality filter will affect that quality of the image. Most of the time the planet is just too bright and you are really trying to reduce the glare. You should probably try putting an aperture mask on your telescope. Reduce the aperture and it should reduce the glare. Also, when viewing, I will run high magnification, if seeing will allow it, to dim the planet and make the detail visible. http://www.lpl.arizona.edu/~rhill/alpo/marstuff/articles/FILTERS1.HTM http://www.go-astronomy.com/telescopes/planetary-filters.htm Dave -----Original Message----- From: utah-astronomy-bounces+david.dunn=albertsons.com@mailman.xmission.com [mailto:utah-astronomy-bounces+david.dunn=albertsons.com@mailman.xmissio n.com] On Behalf Of Scott A. Holdsworth Sent: Monday, June 25, 2007 11:02 PM To: Utah Astronomy Subject: Re: [Utah-astronomy] Glare through Telescope After getting the telescope I realized I wanted to capture the images I found. I looked at the options of an imager or a webcam, but thought the Optio T10 (6 MegaPixel) would be higher quality. Plus, I really enjoy using the camera. The touchscreen makes it easy to control once it is attached to the telescope. So I found an adapter which is working pretty good. 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. As far as viewing different planets I've heard that different filters will help get better pictures. Anyone have a chart that says what is good for what? I'll I'm thinking of that, what do I need to do to view the sun. Do I need a completely different telescope? Thanks for all your help. -Scott A. Holdsworth
I think that it's way too early for filters in the sort of photography you're doing. As others have said, the issue is exposure. Once you get exposure correct, you'd rather have light from all bands in your image. You can then work with Photoshop or another editing program to bring out or suppress the details you want. The problem that cameras have (DSLRs included) is that the automatic exposure typically averages light over several parts of the field. Since the moon, Venus, etc often cover only a small part of the area, the average tells the camera there's less light than there really is. So the exposure time is jacked up. Many cameras--point and shoot included--have a feature that will let you knock the exposure back by a stop or two. This might be an option open to you if you can't directly control the shutter speed. As far as infrared is concerned, many (most?) digital cameras have an IR filter directly in front of the sensor. So you're probably not being affected by infrared. Michael On Jun 26, 2007, at 7:00 AM, Dunn, David wrote:
You can use filters to bring out certain types of features. In my experience, the detail that became visible was rough detail. The fine stuff along the edges of Jupiter's cloud bands was lost when filtered. There are many web pages with lists of what the filters will help you see. I just did a Google on filters planets and it came up with a bunch of pages. I have included two links that came from that list but there were many more. One more thing to consider about filters is their quality. A poor quality filter will affect that quality of the image.
participants (5)
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Chuck Hards -
Dunn, David -
Kurt Fisher -
Michael Carnes -
Scott A. Holdsworth