One neat trck with any lens on the Astrotrac it to photograph one click stop above the maximum aperture of a given lens. IE: a F2.8 will do better at f3.5...a...
6570
mrmhawkins
May 9, 2013 4:40 pm
Thanks for the tip I was considering buying the canon 100 macro F2.8 that should give me 160 plus I would have a top rated macro for another avenue I could do...
6571
Shevill Mathers
shevillmathers
May 9, 2013 5:56 pm
Hi Folks, Some excellent advice and lens examples for astro use from one of the leading astrophotographers. And they do not have to brand new. ...
6572
mrmhawkins
May 9, 2013 6:19 pm
Thanks for the link shevill Sent from my BlackBerry® wireless device ... From: Shevill Mathers <shevillm@...> Sender: astrotrac@yahoogroups.com Date:...
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paulo mesquita
cybermices
May 9, 2013 7:09 pm
the coma is one of the reasons for the suggestion to photograph one step above (F3.5) The 100m macro is great. I'm also looking at the sigma 150mm f2,8 and the...
6574
Christian van den Berge
generex_nu
May 9, 2013 7:50 pm
Please not that the coma as well as sharpness will differ for each lens. To increase the F one stop is great, but experiment with it to check for the best...
6575
H P
hpholcomb
May 9, 2013 9:34 pm
Hey Matt, and welcome! Paulo gave you sound advice. Generally, no IS feature is needed on a cam that's on a tripod. If one has a lens with IS and is doing...
6576
mrmhawkins
May 10, 2013 8:53 am
Thanks Perry, despite a lot to learn I feel advice that is freely given within this AT group would be of a great help and either speed things up or reduce...
6577
paulo mesquita
cybermices
May 10, 2013 9:23 am
Perry is one of the "wise ones" so write down all he says. I do. Btw I got carried away with all the talk on lenses (your fault) and last nigh bought a Sigma...
6578
mrmhawkins
May 10, 2013 9:34 am
Lol, I deleted my Paypal account as I tend to spend out after a few beers and what seems a good idea after having a few beers turns out not to be the case...
6579
leavittg27
May 10, 2013 2:52 pm
I've had my AstroTrac for a year now and love it. But when I attempt to go higher in sky (even towards zenith) I'm getting some shifting problems and have to...
6580
skysea4me
May 10, 2013 5:14 pm
Hi Darryl -- Could you please tell where online one could get the slip joint washer you describe in your "Tips and Tricks"? I've looked everywhere without...
6581
mrmhawkins
May 10, 2013 5:18 pm
Hi not to answer your question directly but an alternative is to use a rubber band hope this helps Sent from my BlackBerry® wireless device ... From:...
6582
Koen Miskotte
fanofsykes
May 10, 2013 6:53 pm
Hello Doug, I bought a couple of slip joint washers at Amazon.com. ...
6583
Darryl
astroinventor
May 10, 2013 8:11 pm
Doug: The link provided by Koen Miskotte will take you to an Amazon.com web site where you can order the slip joint washer. The 1 23/32" diameter one is a bit...
6584
Darryl
astroinventor
May 10, 2013 8:25 pm
Gary: I use the Acratech GP ball head. It's expensive at around $ 400.00, but it's really a beautifully machined and engineered unit and I love it. For...
6585
leavittg27@...
leavittg27
May 11, 2013 1:49 pm
Darryl: Your advice was taken seriously and used last night when I primarily used just the friction knob on the 498RC2 as you suggested. I also added a...
6586
ianmgds
May 12, 2013 1:39 pm
Hi all. Just sold my frac and mount and am getting an AT in the next few days to run through standard equipment. I have been bitten by the bug and want more...
6587
skysea4me
May 12, 2013 11:15 pm
Excellent. Thanks Darryl, Koen for that link. I'll get it. Clear skies, Doug...
6588
skysea4me
May 13, 2013 12:34 am
On Paulo's comment: The 135mm is a wonderful lens not just for AT but also general photography (It is fabulous for portraits, among other things.) I love it....
6589
summitwalker
May 20, 2013 5:33 pm
It is a myth that putting a lens onto a crop sensor camera acts as a focal length multiplier, a 100mm lens is still a 100mm lens, it just the crop factor we...
6590
summitwalker
May 20, 2013 5:47 pm
I agree with the Samyang 14 f2.8 and the Tokina 11-16 f2.8. I haven't tried the other two but the Samyang (also sold as Rokinon) and the Tokina are really good...
6591
paulo mesquita
cybermices
May 20, 2013 8:27 pm
wow...I feel like one of those guys that 500 yars ago believed the earth was flat!!! I always thought it was a x1.60 maginifcation factor. What it really is a...
6592
smaviddith60
May 20, 2013 10:28 pm
Took my astrotrac,wedge and a heavy duty manfrotto studio tripod as I was concerned the travel pier would be a problem on uneven ground. The only real problem...
6593
aziz mahmood
mym00n
May 20, 2013 11:42 pm
Paulo Yes you need this as we are here talking camera lenses for imaging and not with telescopes http://www.howardedin.com/articles/fov.html And your zoom in...
6594
paulo mesquita
cybermices
May 21, 2013 12:06 am
Hi aziz, thanks for the link. I also have a good one (New Astronomy CCD calc) its a free SW that actually shows some objects when comparing the FOV's. However,...
6595
Patrick Wilson
wilsonp195
May 21, 2013 8:55 am
Something I've found invaluable for helping plan imaging sessions, particularly object selection and what available focal length optics I have is the following...
6596
H P
hpholcomb
May 22, 2013 7:11 pm
No, magnification is not changed. The native focal length of the optic being used is being modified. That's why there is "native focal length" and "apparent...
6597
H P
hpholcomb
May 23, 2013 12:32 am
Hey Patrick, I use Starry Night Pro Plus 6 to do a lot of my planning. However, one has to input the sizes, in degrees, of each FL of interest into that...
6598
Chris Bernardi
fraktalnoiz
May 23, 2013 2:15 am
For anyone who might be interested.... I use Starmap Pro on my iPad and iPhone and it has a section that lets me enter in all my scopes, reducers, eyepieces...
