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Moonshots with the Pentax-Q
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PostPosted: Mon Feb 25, 2013 10:03 am    Post subject: Moonshots with the Pentax-Q Reply with quote

That was the initial purpose for this cam: Using the extreme crop factor to turn a 300mm and a 500mm into a big telescope.

The results are less good that I expected, even taking into account the strong wind there was blowing yesterday night. The tripod was noticeably shaked by the wind.

#1 Tokina 300mm f5.6. Processing done: Cropping the central area, some NR, slight contrast push.


#2 Tamron 500mm SP. Similar processing. No crop.


PostPosted: Mon Feb 25, 2013 10:17 am    Post subject: Reply with quote

Jes wrote:
The tripod was noticeably shaked by the wind

not that bad for the Q with the tokina, I would expect worst


PostPosted: Mon Feb 25, 2013 10:51 am    Post subject: Re: Moonshots with the Pentax-Q Reply with quote

Jesito wrote:
That was the initial purpose for this cam: Using the extreme crop factor to turn a 300mm and a 500mm into a big telescope.

The results are less good that I expected, even taking into account the strong wind there was blowing yesterday night. The tripod was noticeably shaked by the wind.

I can see why you're disappointed Jes. You'd get no worse results cropping a pic from a bigger sensor, probably a lot better.


PostPosted: Mon Feb 25, 2013 1:04 pm    Post subject: Reply with quote

poilu wrote:
Jes wrote:
The tripod was noticeably shaked by the wind

not that bad for the Q with the tokina, I would expect worst


Thanks, Poilu. I think owning the Q for moon shots is not worthwhile, so I discard that way.

peterqd wrote:
Jesito wrote:
That was the initial purpose for this cam: Using the extreme crop factor to turn a 300mm and a 500mm into a big telescope.

The results are less good that I expected, even taking into account the strong wind there was blowing yesterday night. The tripod was noticeably shaked by the wind.

I can see why you're disappointed Jes. You'd get no worse results cropping a pic from a bigger sensor, probably a lot better.


You're right Peter. I've to find out which is the sweet point of the moonshot setups (balance between focal length and cropping factor). I've seen really nice pictures from a compact cam and a telescope. I got better results from the Olympus E-1 and the same Tokina 300mm. I have to repeat the same testing again and compare it with different crop size sensor cameras.

Thanks to both for commenting.


PostPosted: Mon Feb 25, 2013 9:08 pm    Post subject: Reply with quote

Both the Tokina and the Tamron are not made for the high resolutios needed by the Q.
I had similar, maybe slightly better results with my Celestron 500mm F3.6 and the Q - very disappointing
But good samples can be found on the internet.
http://www.pentaxforums.com/forums/pentax-q/173602-reach-q-images.html

I have Pentax Q and Nikon 180/2.8 ED here waiting for clear skies - the Nikon is known to be very sharp, I hope it might be good enough for the Q!


Last edited by ForenSeil on Mon Feb 25, 2013 11:06 pm; edited 1 time in total


PostPosted: Mon Feb 25, 2013 10:33 pm    Post subject: Reply with quote

ForenSeil wrote:
Both the Tokina and the Tamron are not made for the high resolutios needed by the Q.
I had similar, maybe slightly better results with my Celestron 500mm F3.6 and the Q

I have Pentax Q and Nikon 180/2.8 ED here waiting for clear skies - the Nikon is known to be very sharp, I hope it might be good enough for the Q!


Look forward to see your samples with the Nikon.

I'm waiting for more adapters to come. Then I'll try my other (sharper) lenses.
Thanks for commenting Smile


PostPosted: Mon Feb 25, 2013 11:25 pm    Post subject: Reply with quote

Scroll down a little: http://www.pentaxforums.com/forums/pentax-q/173602-reach-q-images-28.html
Direct link: http://www.pentaxforums.com/forums/attachments/pentax-q/155873d1358527190-reach-q-images-imgp0093.jpg
Made with a 560mm focal length telescope.
You can get really good results with the Q!


PostPosted: Tue Feb 26, 2013 5:26 am    Post subject: Reply with quote

Thanks for posting these Jes,you never know until you try something new. Very Happy I hope your other lenses make this Q shine. Cool


PostPosted: Tue Feb 26, 2013 6:06 am    Post subject: Reply with quote

Yes, I've got better results with E-PL1 + Tair-3S handheld. But at least now we know that Q won't give super moonshots with our glass.

Though the shot that ForenSeil linked to makes me pause:

My understanding is that 560mm telescope is not that different from 500mm Mirror lens (or is it?) and Tamron is one of the better mirrors. So what gives? Does anyone have an explanation? Perhaps, it's the result of the wind and shaky tripod after all...


PostPosted: Tue Feb 26, 2013 2:01 pm    Post subject: Reply with quote

ForenSeil wrote:
Scroll down a little: http://www.pentaxforums.com/forums/pentax-q/173602-reach-q-images-28.html
Direct link: http://www.pentaxforums.com/forums/attachments/pentax-q/155873d1358527190-reach-q-images-imgp0093.jpg
Made with a 560mm focal length telescope.
You can get really good results with the Q!


Impressive. Thanks for the pointer. The answer is the "stacking" inside, that opens new paths for investigation Smile


mo wrote:
Thanks for posting these Jes,you never know until you try something new. Very Happy I hope your other lenses make this Q shine. Cool


Thanks, Mo. For closeups is much easier Wink
I'll keep trying the moonshots by now, (until I fix the NEX or get a replacement)...


fermy wrote:
Yes, I've got better results with E-PL1 + Tair-3S handheld. But at least now we know that Q won't give super moonshots with our glass.

Though the shot that ForenSeil linked to makes me pause:
...
My understanding is that 560mm telescope is not that different from 500mm Mirror lens (or is it?) and Tamron is one of the better mirrors. So what gives? Does anyone have an explanation? Perhaps, it's the result of the wind and shaky tripod after all...


Thanks for the comment, Fermy. The secret behind seems to be taking 5 sequential shots and stacking them together with an specialized program. This is very common on macro shots, a sample of a spider done by an spanish colleague (Fardels) who stacks 128 shots together:



PostPosted: Tue Feb 26, 2013 2:22 pm    Post subject: Reply with quote

The results are much poorer compared to the ones I got from the GF1 + Tokina 300 f/5.6 + 2x Teleconverter (that were no good...)



I have to try the same setup with the Q.


PostPosted: Tue Feb 26, 2013 5:22 pm    Post subject: Reply with quote

I still think the major problem of all these lenses is the low resolution.
Stacking only removes "heat-flickering" in this case.
I think processing lenses might be a really good chance - but not all of them are nice at infinity.
Good telescopes (no matter if ot's an refractor or mirror-telescope) are only limited by diffraction in center, while those catadioptric mirror lenses and cheaper tele lenses are far away from that.


PostPosted: Tue Feb 26, 2013 5:35 pm    Post subject: Re: Moonshots with the Pentax-Q Reply with quote

peterqd wrote:
Jesito wrote:
That was the initial purpose for this cam: Using the extreme crop factor to turn a 300mm and a 500mm into a big telescope.

The results are less good that I expected, even taking into account the strong wind there was blowing yesterday night. The tripod was noticeably shaked by the wind.

I can see why you're disappointed Jes. You'd get no worse results cropping a pic from a bigger sensor, probably a lot better.


+1 surely will lot better I remember for many good moon shoots on this forum.


PostPosted: Tue Feb 26, 2013 5:45 pm    Post subject: Reply with quote

ForenSeil wrote:

Good telescopes (no matter if ot's an refractor or mirror-telescope) are only limited by diffraction in center, while those catadioptric mirror lenses and cheaper tele lenses are far away from that.


That's a pretty bold and sweeping statement. "Good" is not a very well defined term. What sort of prices are we talking here? And why do you think they are diffraction limited? Are there any resolution tests on these scopes?


PostPosted: Tue Feb 26, 2013 5:52 pm    Post subject: Reply with quote

Forenseil did a shocking result with cheap telescope, I remember for that it was faster, better than most old lens in long focal length what I seen.


PostPosted: Tue Feb 26, 2013 6:00 pm    Post subject: Reply with quote

That's why I am asking since I want to learn. It could be that "cheap" telescope is pretty expensive in lens terms, or it could be that the result is due to superior mount for this kinds of shot or it could be that telescopes are optimized for real infinity, while taking lenses are not. There is a lot of questions to discuss here....

Here's moonshot with Panasonic 100-300 on G2 (not mine):


PostPosted: Tue Feb 26, 2013 8:54 pm    Post subject: Reply with quote

Quote:
That's why I am asking since I want to learn. It could be that "cheap" telescope is pretty expensive in lens terms, or it could be that the result is due to superior mount for this kinds of shot or it could be that telescopes are optimized for real infinity, while taking lenses are not. There is a lot of questions to discuss here....

Telescopes a generally much cheaper than comparable (focal length and speed) photographic lenses in my experience. They are cheaper because
-Most of them are made in China
-They are less compact
-Most of them don't need field flattener, coma reducer, floating- or similar correcting elements
-Noone cares about bokeh and color balance etc.
-Helicoids are much cheaper, because they don't need to hold the whole lens etc.
And yes telescope mounts are also generally better than photographic tripods, but also much more heavy.
And yes all telescopes are optimized to work at infnity, but most of them also work nice up to a few meters.

fermy wrote:
ForenSeil wrote:

Good telescopes (no matter if it's an refractor or mirror-telescope) are only limited by diffraction in center, while those catadioptric mirror lenses and cheaper tele lenses are far away from that.


That's a pretty bold and sweeping statement. "Good" is not a very well defined term. What sort of prices are we talking here? And why do you think they are diffraction limited? Are there any resolution tests on these scopes?

"Good" for an "small" astronomical telescope means that they are (nearly) able to outresolve their physical limits imo.

Attila wrote:
Forenseil did a shocking result with cheap telescope, I remember for that it was faster, better than most old lens in long focal length what I seen.

Yup, I bought an "Meade Astronomical Telescope 291" 900mm F14.75 locally for a few bucks and it was suprisingly good - I guess limited only by diffraction.
http://forum.mflenses.com/meade-astronomical-telescope-291-f900mm-f114-75-on-nex-t54263,highlight,%2Bmeade.html
Infected by the good IQ for a low price I also bought an Celestron C130 (~2000mm F15,4) Maksutov locally
http://forum.mflenses.com/viewtopic,p,1279425.html#1279425 , an SkyWatcher 1000mm F7,? Refractor (no thread here, it was a bit disappoiting) and an Celestron 500mm F3.6 Schmidt-Newton http://forum.mflenses.com/celestron-500mm-f3-6-comet-catcher-t55297,highlight,%2Bcelestron.html but not one of them was reached the cheap Meade telescope in resolution (they all should have a lot more physically)!


Last edited by ForenSeil on Wed Feb 27, 2013 6:42 pm; edited 1 time in total


PostPosted: Tue Feb 26, 2013 9:40 pm    Post subject: Reply with quote

Good to hear you are not giving up on the Q and the Moon. I hope you have a non windy night for your next tests. I am almost tempted to take the Tamron mirror to NZ with me and try a moonshot over there Laughing


PostPosted: Tue Feb 26, 2013 9:49 pm    Post subject: Reply with quote

mo wrote:
Good to hear you are not giving up on the Q and the Moon. I hope you have a non windy night for your next tests. I am almost tempted to take the Tamron mirror to NZ with me and try a moonshot over there Laughing

That will be even more upside down than in Aus! Smile


PostPosted: Fri Mar 01, 2013 2:52 am    Post subject: Reply with quote

Here a proove that the Pentax Q sensor is not the limiting factor for moon shooting.
Nikon 180/2.8 ED @ F4 + Pentax Q

Single exposure through a dirty window, made with self-timer. Seeing was crappy due strong heat flickering (watch in HD!): http://www.youtube.com/watch?v=aPLRRDclcEw&feature=youtu.be
I whish I had a ~500mm lens with such a high resolution like the 180/2.8 - that would be a powerhouse combo!
If seeing was better I would have tried my 900mm F14,75 Meade Fraunhofer on the Q


PostPosted: Tue Jan 24, 2017 4:49 pm    Post subject: Pentax q 10 mto 550 f 8.5 m39 Reply with quote

[url=http://forum.mflenses.com/userpix/20171/big_915_PSX_20170104_222911_1.jpg]

Last edited by dr.volkan on Tue Mar 14, 2017 11:38 am; edited 1 time in total


PostPosted: Tue Mar 14, 2017 8:52 am    Post subject: Re: Pentax q 10 mto 550 f 8.5 m39 Reply with quote

dr.volkan wrote:




Second photo beroflex 500mm f:8 normal tele lens+PentaxQ 10



PostPosted: Tue Mar 14, 2017 5:14 pm    Post subject: Reply with quote

Were the last two using the Tamron mirror? The first one isn't too bad, but the second one looks overprocessed.

Using APS-C digitals, I have been able to get more detail with the Tamron mirror than you're showing. It's an excellent lens, rivaling a very sharp 500mm refractor I own. This one was taken with a NEX 7, ISO 100, 1/125 sec. This is also a full-color photo -- you can see some slight colorations in the moon surface.



PostPosted: Tue Mar 14, 2017 5:22 pm    Post subject: Reply with quote

cooltouch wrote:
Were the last two using the Tamron mirror? The first one isn't too bad, but the second one looks overprocessed.

Using APS-C digitals, I have been able to get more detail with the Tamron mirror than you're showing. It's an excellent lens, rivaling a very sharp 500mm refractor I own. This one was taken with a NEX 7, ISO 100, 1/125 sec. This is also a full-color photo -- you can see some slight colorations in the moon surface.

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