pentax astro tracking

[zardos123]

been thinking about one of these for a while, these are the best results i,ve seen. anyone using one?

http://forums.dpreview.com/forums/read.asp?forum=1036&message=39284452

regards brad

[iceman]

Peter Langdown (peterl) had one at IISAC2011. He posted some results in the IISAC2011 thread.
It looked like a great bit of gear. Very handy.

[jjjnettie]

I was amazed at Peter's. It puts astrophotography into everyones reach.

[renormalised]

What mount did he have his camera on??

[iceman]

A static tripod!

[renormalised]

No barn door type tracking mount attached to the tripod?? Or any other sort of screw type driven tracking head?? Just the camera attached to the tripod....

[jjjnettie]

That's right. Amazing huh.
The length of exposure you can get all depends on the size of your lens. A 10-22 lens will get you around 8min before trailing, a 300mm maybe a minute. I haven't done the math, so that's just approx.

[Lester]

Very interesting. Here is another link with some info.

http://www.dpreview.com/news/2011/7/8/pentaxastroreport

[naskies]

This is a fantastic idea - perfect for "everyday" photographers dabbling with astrophotography, and for occasional shooting like with the recent comet chasing. If the specs/results are to be believed (e.g. 2-3 mins tracking even up to 200 mm focal length, depending upon declination), I think this would give portable mounts like the Astrotrac some stiff competition.

Carl - the "mount" is inside the camera itself... their system physically moves the image sensor (i.e. the feature normally used for image stabilisation) to track the stars. There's a little add-on unit that contains a GPS, magnetometer, and compass so that the camera can figure out the coordinates of what it's pointing at. Very neat!

[renormalised]

So, everyone is going to rush out and buy Pentax K5's or better:):P

Pity the in built picture stabilisation feature is a Pentax thing and not common to all camera makes.

[OICURMT]

Sony Alpha's also have the IS in the body... I wonder if Sony will come out with a module as well :shrug:

[erick]

What about the story that K5 production has ceased?

I see I can buy the body for $911 from Hong Kong plus shipping.

Locally, the GPS Unit is $233 at one online place I have looked.

Tempting.

[Nico13]

I have Pentax gear and run a K5, my question is would it still function if you actually had it on a tracking mount rather than a fixed tripod.

What method of determining how far to shift the sensor, is it using pure calculations from location and camera direction and inclination.
Or is it more like the auto guide systems we see where it detects light path over pixels and adjusts accordingly?

If it's the later it could still be used on a mount and give longer exposures without the need for auto guiding.

Nico.

[Poita]

This link lets you see the replies more easily.

http://forums.dpreview.com/forums/readflat.asp?forum=1036&thread=39284452

As far as I understand it, Pentax has an anti-shake system to remove blur from hand held camera shots. Unlike other DSLR vendors that put the anti-shake motors etc. inside the lens, the Pentax moves the CCD sensor inside the camera to eliminate the shake.

What they appear to have done is utilised that moveable sensor technology and coupled it with a GPS unit to allow the sensor to move to track the movement of the stars for long exposures on a normal static tripod without getting star trails. Brilliant!

Good on Pentax for doing something directly for the astro community.
This holds so much promise. I wonder if the system could be extended to effectively be an active optics system if you have it on an equatorial mount, and have the sensor move to iron out the errors in your mount.

Another discussion here:
http://www.astronomyforum.net/astronomy-digital-cameras-forum/113354-post-your-astrophotography-images-tracking-results-pentax-astrotracer-o-gps1-unit.html

[Poita]

No, it can't be used with a tracking mount unfortunately.

Also, anyone coveting one should read the last post here:
http://www.astronomyforum.net/astronomy-digital-cameras-forum/113354-post-your-astrophotography-images-tracking-results-pentax-astrotracer-o-gps1-unit-4.html

I'm very hopeful for this technology in the future, could be something incorporated into future cameras with better results at long focal lengths.

[jamiep]

Big Dave - from melbourne used one for this shot ... see his thread...

http://www.iceinspace.com.au/forum/showthread.php?t=84594

Jamie

[ZeroID]

My Konica Minolta 7D Dynax has the stabilisation built in to the body rather than the lens. This is the basis for the SONY Alpha's camera range. SONY bought the KM camera business about 4-5 years ago I think.

Good as it means I can get the capability with any compatible mount lens but they don't have that clever feature for sure. Although I did find it had a really cool intervalometer feature built in. 240 frames with delays up to 1 hour between. Needs an external Power supply obviously for that time but could be useful.

[zardos123]

What about the story that K5 production has ceased?

I see I can buy the body for $911 from Hong Kong plus shipping.

Locally, the GPS Unit is $233 at one online place I have looked.

Tempting.

eric, pentax only have two dslr production lines one for k-r and one for the k-5.....so at the end of a line they produce product for the next six months ,then begin retooling for the next model they generally have an 18month product cycle expect the reports of a new model in the next month or two, hopefully ricoh having just bought pentax from hoya will maintain pentax's habit of making all new models backwards compatible, in fact there is likely to be a big improvement in the implementation of this software if there past behaviour is repeated. It will have to be a big improvment to make me upgrade from the k-5, after 5 or 6 dslr bodies this one ticks all the boxes and is a keeper, there is talk they will put the 24mp sony sensor in to replace the current 16mp if that is the only major change then i,ll stick with the k-5, 16mp is plenty for the stuff i do. there are rumours that they will release a firmware update after the new body to tweek the gps unit
regards brad

[naskies]

Aside from Canon's obvious R&D investment in stabilisation built into the lens, they've claimed that in-body stabilisation at long focal lengths isn't nearly as effective.

I think that in-body stabilisation would be really great for the prime lenses that are unlikely to have IS built-in anytime soon (e.g. the wide angle and standard tele f/1.2 and f/1.4), not to mention the astro tracking feature.

I hope more DSLR manufacturers pick up on the astro features... mass production = better prices for all of us :)

[zardos123]

I think your right the in lens stabilisation is a little bit more effective about one stop (thinking about slow shutter speeds hand held) cannon/nikon will do about a 4 stop improvement, with pentax you can only get 3.5 to 4 on short lengths over 200mm its more like 2 to 3 however the trade off is any lens ever made that fits is stabilised makes old classic's and ebay bargains a lot more versatile :D

[Nico13]

Yes I agree, Richo have allied themselves with Pentax lens mount in the past and I see no reason for things to go down hill for Pentax now it is owned by Richo. Things may actually pick up for the Brand.

Nico.

[peterl]

Yes, Keep an eye on Pentax in 2012..
They may have some big surprises this year.They have been quietly sneaking up on other brands recently.
The K5 has some great specs, especially low noise up to 1600 to 3200iso as some have already found out..
My first try with the astrotrac function was at IISAC at Lostock.
It was when I got home and had a real look at some images,they just blew me away..This camera is rock solid and weather resistant which is good in dew conditions.
This image of Comet Lovejoy shot on 1600 iso.4.5 minutes.Pentax Lens 16-45mm F4. left open at F4 hence slight coma at edges.I could have closed down to reduce this but wanted a much light as possible to pick up comet detail.As Mike said earlier all sitting on a STATIC Manfrotto 190 tripod.Once you set up the fine calibration you can then take as many shots as you like.If you move and change location you need to recalibrate
again as Latitude and logitude has changed..

Peter.

[erick]

Well it has taken some time to get around to it but I've finally ordered a K-5 IIs body. Not many new ones left around the world now but the price was a bargain! Next to find the cheapest GPS unit and I'll try a bit of static tripod tracking! :)

[gregbradley]

That camera gets good reviews plus I think for a DSLR styled camera its very appealling especially in the silver version.

A tracking sensor unit is very clever and that sensor is the venerable Sony Exmor 16mp APSc sensor which is in many cameras including the Fuji X series. It can be good up to ISO6400 depending on the camera.

Greg.

[Poita]

I have the GPS unit, but no camera!

If you would like it, I'll sell it for $160 + post :)

[erick]

I'll be in touch Peter - thanks. I thought it had long gone when I saw you had it for sale earlier.

[erick]

Thanks Greg, I'm looking forward to learning how to use the K5. Glad to hear it is well regarded. :)

[cybereye]

This option is also available on the K30 which is, more or less, an entry level Pentax. I have a K30 but don't have the GPS unit... one day.... :D

Cheers,
Mario

[erick]

I have the K5 (thanks Canadian Ebay shop) and the GPS unit (thanks Peter).

Tried last night under a beautiful sky in Gembrook and very happy with the "poor man's" astrotracking. Attached - with and without tracking (2 min 30 sec exposure). And a tracked Omega Centauri shot with the telephoto at around 200mm (1 min 30 sec exposure). What a clever setup for quick and easy skyscapes.

I need to use better lenses than the one I brought to Australia with me and some more experimentation with the GPS/astrotracker calibration, but a good start.

It was also great to get back out under southern skies - Omega Centauri, 47 Tuc, Wishing Well cluster, Jewel Box, Carina Nebula - I missed you all.

[elfinke]

That third image is a ripper, Erick. What glass did you have attached at 200mm for it? It's a far better image than any I've managed at anything like 200mm with my astrotracer and my K30. Though I have purchased a new bit of glass recently, and built a barndoor tracker to aid, I'm hoping the combination of the two will lead to some excellent bulb exposures - once this rotten east coast weather buggers off that is!

[Poita]

So happy to see some images from it, glad it is working for you, they look great!

[erick]

Thanks Peter and Trev. Trev, the lens is a Pentax-F zoom f/3.5-4.5, 35-135mm. It is a 35mm film lens so with the sensor being smaller than 35mm full frame, the lens is performing as a 53-203mm. You'll see that the stars are certainly not round. In other shots there was gross coma in places. I have a Samyang f/2.8 14mm on order - I'm looking forward to some lovely widefields which is my main objective. Not sure about telephoto. I'll try my various lenses and see how they perform.


Cheers all. I'll be back on the plane next Monday heading back north of the equator to the heat, humidity, dust and light pollution of Israel.