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03-12-2014, 10:06 AM - 2 Likes   #121
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QuoteOriginally posted by baro-nite Quote
Have a look here:

https://www.pentaxforums.com/forums/12-post-your-photos/6-how-upload-photos-b...tart-here.html

For attached images you need to keep them to 1280x800 or smaller to avoid automatic re-sizing.
I know. There is something strange with the file. Have tried another computer, different browsers. I could not upload to DPreview either. Well here is a link to the image as it should be.

Edit: Link or URL removed. I found the fault. The deep reds of the image messed it up. I converted the image to yellowish. I think its ok now. Not red H-alpha, but still ...

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Last edited by NoRules; 03-12-2014 at 01:42 PM.
03-12-2014, 08:37 PM   #122
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Super capture. Is this image cropped or is this the full field of view? Are there different settngs or filters on the Coronado? If so would love to see what they do. A Q sun video would be a thing of beauty.
thanks for sharing
barondla
03-12-2014, 10:59 PM   #123
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Hi Barondla,
Thanks! This is a slightly cropped image. The Coronados are 400mm lenses with different f.stop. The 60 has an f.stop at 6.7 (the 40 is at f.10, and mainly good for viewing, but I'll bet the original Q could do beautiful stuff on it). The filter in front costs $900, and there is a set screw that can tilt the angle of the filter unit, depending on if you want to see protuberances or surface detail. The Coronados are build either for Calsium K-line or Hydrogen-alpha spectrum. Mine is H-a. A video will never be made. Sorry. I'm not that kind of guy
03-13-2014, 10:01 AM   #124
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Impressive work -- looking forward to seeing more. TFS.

03-14-2014, 06:44 AM   #125
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Next attempt

QuoteOriginally posted by baro-nite Quote
Impressive work -- looking forward to seeing more. TFS.
Allrighty then. I did one more yesterday. Tried to push a little harder. Still some wrinkles to iron out though. Q7+ DIY T-mount adapter+ Coronado 60, Prime focus.
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04-02-2014, 10:42 AM   #126
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Hello everyone.

crewl1 recommended me too look into this thread given my plans to buy and combine a Q with a Apo ED telescope (Equinox-120 PRO OTA) for wildlife and astro photography.
I wounder. does anyone participating in this thread have any experience or knowledge regarding on how well the Qs (the Q10 and the Q7 respectively) performs with such a scope.
Crewl1 suggested that the Q7 might yield better results despite having less crop-factor, and his photos would seem to give his claim weight (https://www.pentaxforums.com/forums/136-pentax-q/173602-reach-q-images-63.html#post2750571).

Anyone have any information or thought on the matter?
04-02-2014, 02:37 PM   #127
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Q7 is definitely superior in image quality. Google tells me your scope is 900mm f7.5? f7.5 is into diffraction on the Q series but it should be acceptable. You are going to need an absolutely rock steady mount though. It will be roughly 4500-5000mm equivalent in 35mm format terms on the Q7/Q10 & Q. Also, unless you use the official Pentax Q > K adapter as part of your fitting the Q to the scope, you will be limited to 2sec exposures max, and jello effect below 1/13sec min. Something to consider.
04-03-2014, 07:04 AM   #128
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QuoteOriginally posted by jezza323 Quote
Q7 is definitely superior in image quality. Google tells me your scope is 900mm f7.5? f7.5 is into diffraction on the Q series but it should be acceptable. You are going to need an absolutely rock steady mount though. It will be roughly 4500-5000mm equivalent in 35mm format terms on the Q7/Q10 & Q. Also, unless you use the official Pentax Q > K adapter as part of your fitting the Q to the scope, you will be limited to 2sec exposures max, and jello effect below 1/13sec min. Something to consider.
Thank you for your reply jezza323. I appreciate it.
It is good that the info you and crewl1 provided has brought my attention to the concept of diffraction, as I was only vaguely familiar with it before your reply.

Its interesting with all the variables. Pixel density (pixels on target), pixel size (affect by f/stop diffraction) lens quality and so on.
This got me thinking, Does anyone know of a calculator or collection of charts showing the relation between these factors?

Because what you really want is some kind of standard of sharpness on a 100% crop. For example, using a Q7, it might turn out that it would be better to go for a 500mm f6.0 than a 900mm 7.5 if the former had a resolution that would allow cropping past the reach of the later (900 mm f 7.5) with details preserved. For what is 12 mega-pixels worth if resolution is basically 2 mp due to heavy diffraction.
Perhaps it is even worth to consider a mirror telescope given their longer reach and aperture relative to price.

There must be some way do find the where the sweet spot is, at last roughly.

04-03-2014, 08:02 AM   #129
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QuoteOriginally posted by Expeditioneer Quote
There must be some way do find the where the sweet spot is, at last roughly.
So much depends on the particular lens involved, there's no substitute for testing the actual lens on the actual camera. But as a general guide, if a lens's sharpest aperture is slower than f/5.6, f/5.6 is probably the sharpest aperture on the Q -- the best compromise between lens sharpness and differaction. And that describes the vast majority of 135-format lenses.
04-14-2014, 07:43 PM   #130
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someone taking pictures of today's lunar eclipse with the Q? !
04-14-2014, 07:50 PM   #131
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I will give it a go if my son allows me to!

Sigma 150-500mm + Q + tripod
04-14-2014, 08:08 PM   #132
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i'll try with my telescope and the Q, the focal lenght is 1325 with the crop factor it sucks cause the moon looks so close T_T
04-14-2014, 08:43 PM   #133
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The moon was larger than the frame on the original Q @ 600mm (300mm w 2x TC)

Might not be too bright though, since it will be in eclipse... see how it goes I suppose
04-15-2014, 01:20 AM   #134
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No lunar eclipse photos yet?

Well, I'm not really good at astrophotography but here is my impatient attempt

Last edited by MarinatedHerring; 05-17-2014 at 04:33 PM.
04-15-2014, 01:22 AM   #135
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These are cross posted from the blood moon thread.
Q7 + DA*300

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