#1  
Old 20-09-2005, 03:48 PM
janoskiss's Avatar
janoskiss (Steve H)
Registered User

janoskiss is offline
 
Join Date: Jan 2005
Location: Sale, VIC
Posts: 6,032
Pentax DSLR

I'm looking for some info on Pentax digital SLRs. The *ist DS that a few members own is going for around $900 brand new. That's for the body only, but the bonus is that you can supposedly use old M42 (yes M42 ) screw mount lenses on this camera. That means there are lots of good second hand Pentax, Praktica and some Russian lenses out there.

http://centre.net.au/Pentax_ist_DS_D...dy_0007HX.html

Why do the Pentax seem less popular than Canons and Nikons with similar specs?
What's the diff between the Pentax DL & DS models?

I am only dreaming at the moment, but if I did get a DSLR it would be for astrophotography.
Reply With Quote
  #2  
Old 20-09-2005, 04:16 PM
h0ughy's Avatar
h0ughy (David)
DOGHOUSE REBORN

h0ughy is offline
 
Join Date: Apr 2005
Location: NEWCASTLE NSW Australia
Posts: 30,586
Steve,

you would have to check the specs side by side to see the difference between the models. There must be something?

you will need an adapter, the Pentax IstDS does not cater for these lenses out of the box, however with a converter it will take any of the older lenses.

For the money its good value!
Reply With Quote
  #3  
Old 20-09-2005, 04:41 PM
TidaLpHasE's Avatar
TidaLpHasE
Gone fish'n

TidaLpHasE is offline
 
Join Date: Jul 2005
Location: Melbourne
Posts: 668
This link should help, http://www.dpreview.com/reviews/sidebyside.asp

I have only owned Canons, not sure why they are more popular.

The weight of the camera and the size of the lcd screen seem to be the only difference.
Reply With Quote
  #4  
Old 20-09-2005, 04:53 PM
fringe_dweller's Avatar
fringe_dweller
on the highway to Hell

fringe_dweller is offline
 
Join Date: May 2005
Location: Adelaide
Posts: 2,623
Quote:
Originally Posted by janoskiss

Why do the Pentax seem less popular than Canons and Nikons with similar specs?
I am only dreaming at the moment, but if I did get a DSLR it would be for astrophotography.
Steve, the canons are considered to have the best and biggest range of quality lenses available, also the canons have the CMOS type chip instead of the CCD chip - which is considered superior in low noise and sensitivity in long duration exposure astro stuff, or was? - dont think that is the case now?. Also the canon RAW mode is/was? considered the only true RAW mode out there - RAW mode means zero compression - so it can be manipulated and cleaned up more post imaging(Nikon got into hot water about theirs not being a true RAW mode at one stage) but seeing a lot of people just using jpeg mode with great results - i dont know anymore. Also the canon 20D is prized for the fact that the amp shuts down on long exposures - and as a result you dont have to remove the noise/glow it makes.
With adapting older style lenses there can be issues with back focus and autofocus i think? - pity coz we have some great old K- mount pentax/tamron prime lenses i would like to use from our old pentax manual 35mm film cameras.
I read in Covingtons book that he thought some of the best astro prime lenses were made in the 70's and i think that included some pentax ones.
Also canons image stabilisation on board software/lenses are considered the best and cutting edge at that job (not that that has anything to do with astro work - but bird/action photogrphers love it - dont even need a tripod with telephoto lenses) - also the thing with digital cameras is the proprietry on board software differs in quality - nikon and canon are considered the best in that area - or so I believe - that may be out of date info now.
but with daylight shots there is very little diff between the brands with cameras of equal quality.
kearn

Last edited by fringe_dweller; 20-09-2005 at 05:16 PM.
Reply With Quote
  #5  
Old 20-09-2005, 06:47 PM
acropolite's Avatar
acropolite (Phil)
Registered User

acropolite is offline
 
Join Date: Feb 2005
Location: Launceston Tasmania
Posts: 8,985
I would suggest that no matter what you buy that you go to your local dealer and fire some shots out the door with each type of camera. I did that, and arrived at the conclusion that the performance of the Canon was better and reviews I read backed that up. As Kearn said, normal daylight photo's don't show up the flaws, but things like edges of buildings, lamp posts and shadow detail will give an idea of chromatic abberation and noise/compression problems is shadow detail. I found that in the test shots I took that the 1stDS had quite noticeable compression artifacts in the shadow detail, they may not have been apparent in raw images, but I didn't have the option of testing that thoroughly at the time. The Sigma lens on offer with the 1stDS had severe CA (purple fringing) at the extremeties of the image, once again if I had taken an average pic the abberation may not have been apparent. I would have liked to have had more time with the 1stDS, it's a nice lightweight DSLR and as master h0ughy has shown is capable of excellent results. As h0ughy says the 1stDS is excellent value.
Reply With Quote
  #6  
Old 20-09-2005, 07:48 PM
Dennis
Dazzled by the Cosmos.

Dennis is offline
 
Join Date: May 2005
Location: Brisbane
Posts: 10,871
From a casual browse of various newsgroups, it seems that you are better supported by 3rd party software (e.g. ImagePlus, DSLRFocus) if you use a Canon or Nikon DSLR for astrophotography.

I have a Pentax istDS because I have always liked Pentax and had some older lenses, but at times it is frustrating not to be able to use the various "hacks" and software available to Canon and Nikon owners, to enhance the use of their DSLRs in astrophotography.

Cheers

Dennis
Reply With Quote
  #7  
Old 20-09-2005, 08:16 PM
janoskiss's Avatar
janoskiss (Steve H)
Registered User

janoskiss is offline
 
Join Date: Jan 2005
Location: Sale, VIC
Posts: 6,032
Thanks Dennis, but for what I want to do, I don't see a need for third party software that works with the camera. I just want something that counts the photons falling on its image plane as accurately as possible. After getting the raw data off the camera, any software I use should be independent of where the three arrays of R,G,B values came from. The main thing I'd be interested in is the quality of the raw data collected by the camera's sensor.
Reply With Quote
  #8  
Old 20-09-2005, 09:47 PM
CometGuy's Avatar
CometGuy
Registered User

CometGuy is offline
 
Join Date: Feb 2005
Location: Brisbane
Posts: 942
Its a pity there hasn't been more focus on the istDS for astrophotography. Id love to see more astro results from the camera...anyone?
Reply With Quote
  #9  
Old 20-09-2005, 09:54 PM
CometGuy's Avatar
CometGuy
Registered User

CometGuy is offline
 
Join Date: Feb 2005
Location: Brisbane
Posts: 942
There are various theories about why the istDS hasn't been more successful, best ones I heard:

1. Nobody in Pentax can agree on how to pronounce the cameras name. eg. 'ist DS' or 'star-ist-DS'.
2. The *istDS contains the '*' wildcard that breaks half of the world's software

Well thats what they say on the dpreview forums....so it must be true!


Terry

Last edited by CometGuy; 20-09-2005 at 10:11 PM.
Reply With Quote
  #10  
Old 20-09-2005, 10:05 PM
h0ughy's Avatar
h0ughy (David)
DOGHOUSE REBORN

h0ughy is offline
 
Join Date: Apr 2005
Location: NEWCASTLE NSW Australia
Posts: 30,586
Quote:
Originally Posted by CometGuy
Its a pity there hasn't been more focus on the istDS for astrophotography. Id love to see more astro results from the camera...anyone?

Soon Cometguy, soon. The mount is coming, the camera setup is almost ready and the guidescope has been obtained. Waiting now to put the lot together and get the results. this is hopefully a tase of what is to come. it was unguided and no specific time was set. taken at qld astrofest........

72.7 seconds f1.7
Attached Thumbnails
Click for full-size image (IMGP7219 (Medium).JPG)
62.0 KB75 views
Reply With Quote
  #11  
Old 20-09-2005, 10:22 PM
janoskiss's Avatar
janoskiss (Steve H)
Registered User

janoskiss is offline
 
Join Date: Jan 2005
Location: Sale, VIC
Posts: 6,032
Houghy, the shots you've posted on iceinspace have been very good. Were they all (or most of them) taken with your Pentax DS? Also, coz of the resolution and detail reduction needed to squeeze an image into forum guideline specs, I'm curious how the full res pics look. Finally, have you used film before moving onto digital?

Terry, I agree, *ist is just about the stupidest name for any product ever.
Reply With Quote
  #12  
Old 20-09-2005, 10:27 PM
h0ughy's Avatar
h0ughy (David)
DOGHOUSE REBORN

h0ughy is offline
 
Join Date: Apr 2005
Location: NEWCASTLE NSW Australia
Posts: 30,586
well its got you interested in a strange named product! yes on all accounts, and yes I have used film but without too much success. last time I used film was total lunar eclipse a few years ago.Steve Pm me with you email and I will send a few full res pictures. only if you have broadband!
Reply With Quote
  #13  
Old 20-09-2005, 11:12 PM
janoskiss's Avatar
janoskiss (Steve H)
Registered User

janoskiss is offline
 
Join Date: Jan 2005
Location: Sale, VIC
Posts: 6,032
What really got me interested was the price and the backward compatibility with old film SLR lenses (and the Pentax brand name I must admit). I sent you PM Houghy.
Reply With Quote
  #14  
Old 20-09-2005, 11:16 PM
h0ughy's Avatar
h0ughy (David)
DOGHOUSE REBORN

h0ughy is offline
 
Join Date: Apr 2005
Location: NEWCASTLE NSW Australia
Posts: 30,586
Quote:
Originally Posted by janoskiss
What really got me interested was the price and the backward compatibility with old film SLR lenses (and the Pentax brand name I must admit). I sent you PM Houghy.

Check you rapidly overflowing mailbox Steve, let me know what you think
Reply With Quote
  #15  
Old 21-09-2005, 03:34 AM
RapidEye's Avatar
RapidEye
Carbon Star Junkie

RapidEye is offline
 
Join Date: Aug 2005
Location: North Carolina - USA
Posts: 202
Quote:
Originally Posted by janoskiss
What really got me interested was the price and the backward compatibility with old film SLR lenses
Agreed - the Digital Canon stuff takes ALL of the EOS lenses and accessories. That gets you into a large pool of equipment with a proven track record.

My father-in-law has a 28-300 zoom lens for his 10 yr old Canon 35mm camera. I tossed it onto my Rebel and it worked like a champ, autofocus and all!

That backward compatiblity can not be overstated enough!

It also gives me a lot of assurance that any equipment I purchase now will be usable on what ever body I buy from Canon 5, 10, or 15 years from now! I wish I could say that for the bag full of Minolta lenses I have sitting in my closet
Reply With Quote
  #16  
Old 21-09-2005, 04:49 AM
Dennis
Dazzled by the Cosmos.

Dennis is offline
 
Join Date: May 2005
Location: Brisbane
Posts: 10,871
Quote:
Originally Posted by janoskiss
Thanks Dennis, but for what I want to do, I don't see a need for third party software that works with the camera. I just want something that counts the photons falling on its image plane as accurately as possible. After getting the raw data off the camera, any software I use should be independent of where the three arrays of R,G,B values came from. The main thing I'd be interested in is the quality of the raw data collected by the camera's sensor.
Just make sure you understand what you may be "throwing away" if you do go down the Pentax path. I haven't explored ImagePlus and DSLRFocus, but I believe they allow you to focus using your notebook computer by downloading and assessing images, as well as performing operations from the PC to e.g. take 10 exposures of 5 mins duration. Some of this can be done with the Pentax, but the implementation for Canon and Nikon seems to be more advanced.

I have used the Pentax Remote Control software (free) and you can perform some limited operations from a PC but it does not seem as flexible and rich as the other 3rd party applications.

In my case, the backwards compatibility with my existing lenses was a more important requirement than the other stuff.

Cheers

Dennis
Reply With Quote
  #17  
Old 09-04-2006, 05:47 PM
stuart
Registered User

stuart is offline
 
Join Date: Apr 2006
Location: Halzelbrook
Posts: 1
Thumbs up old lenses for istD DSLR

Have just bought one panicked when my old K mount adaptall Tamron lenses wouldn't work, read the book.The control menu allows you to set aperture ring to activate and it works with my old lenses, they say that the functions are limited, I am still learning so limitations not known, all 35mm lenses have a factor that decreases the wide angle ability and increses the zoom factor this camera is 1:1.5 really expensive bodies are 1:1 $6000 + .


It came with a Sigma 18/50 auto focus (digital purpose built)seems quite Ok. Will now try it on my 114 and 200mm 'scopes when I get them back together, I was showing someone a photo in the Jan/Feb Sky & Space magazine, the one with the Asian lady on the cover with a Meade. It has a great article on astro photography plus a free download site for matching scope to camera for deep space stuff, my Tamron lenses were bought in '84 and were tested taking photos of flowers with the DSLR results auger well for good photos whatever they are of.

Last edited by stuart; 09-04-2006 at 07:40 PM.
Reply With Quote
  #18  
Old 10-04-2006, 08:42 PM
leon's Avatar
leon
Registered User

leon is offline
 
Join Date: Apr 2006
Location: ballarat
Posts: 10,804
Question Pentax Ist DSLR's

Hi There

I use my Pentax IstD for Astro-Photography, mainly wide field images.
You are correct, there are heaps of older style lens that will fit, even the screw on types, but beware......
To use the screw on types you obviously need an adaptor that will take the 42mm thread, they are easy enough to get, but put them on your Ist and you will struggle to get the little buggers off.
The tool you get is not suited to remove the adaptor properly, and i litterly had to put mine to the grinding wheel to modify it, the tool that is.
The problem is that when they made these tools they made the little lugs to long, and each time you insert it into the two slots on your camera body to remove it they go in to far and you get stuck, and you cant rotate the adaptor.
I had a hell of a time with it, and ended up with bits of shaved steel in the camera itself, and on the sensor.
My suggestion, dont worry about the screw mount lenses, they are more grief than there worth.
Now secondly, all other lens other than specific digital friendly ones will give you Chromatic aberration and purple fringing around the bright stars.
This is due to the fact that the sensor is not full frame, (being 35mm) and the colours are not equally focus at the focal plane, where the blue light is the biggest culprit, giving you purple fringing and aberration.
I have heaps of Pentax film lenses but find they don't do the job, and have now recentaly ordered a specific Pentax Lens designed specificaly for the IstD.
I'm lucky in a sense that i can try before i buy from my dealer, so i will eventually find a lens suited for my needs
Having said all that the older style lenses do work well for ordinary photography, but are not much when it comes to Wide Field Astro-Photography.

Clear Skies Leon
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 01:07 AM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Advertisement
Lunatico Astronomical
Advertisement
NexDome Observatories
Advertisement
Celestron Australia
Advertisement
Bintel
Advertisement
OzScopes Authorised Dealer
Advertisement
Meade Australia
Advertisement
SkyWatcher Australia
Advertisement
Astronomy and Electronics Centre
Advertisement