If it's the post I believe I remember, Dave had issues with the scope and sent it back for a refund. Too bad, that's the first time I've heard of a problem...
Ok, this is O.T. big time but I am counting on you guys for help. Can anyone point me to a quick & dirty web program, free of course, that gives the...
If you need more specific information, here is my current problem: I have a 80mm f/6 triplet (Lomo) I use for imaging with my DSLR. I have two options for...
If you have both the Televue and Takahashi, why don't you just shoot the same subject with both flatteners and compare the results in Photoshop? Sharpness is...
Hi Crazy Bob! I could easily do that, but the focal length if different (384mm vs 515mm) so how can I adjust of this? What subject would be good for this type...
... 40group.calendar.google.com&ctz=America/New_York ... Thanks Alan, Now that we are about to lose Jupiter for this season we should start going after Saturn....
I'd shoot stars. A problem with testing long lenses with standard test targets is that you need a huge amount of space. Sure, you can shoot close and rack...
At these focal lengths you are going to be significantly undersampling no matter which flattener you use, so resolution at the center of the field is going to...
Think about it this way. The Tak at 1.06 is putting on the chip the central part of the cone of light coming through the scope. The TV at 0.80 is putting stars...
... Thank you all. I actually shot the same star field some time ago, but I forgot to turn on autoguiding, so even these 30s exposures contained a small amount...
The following is not really about refractors but I am allowing posting for those who are interested in DSLR use with their scopes. An interchangeable lens...
For some time, I've been putting together an imaging platform which obviously involves my laptop. Since alot of others out there are already using laptops or...
So I was star testing an APO refractor last night and on the inside focus the rings were nice and bright and on the outside focus the rings were just...
To me it sounds like a combo-platter, a little under correction with some turbulence or surface roughness Ron Jones ... From: "teche70" <teche70@...> To:...
All APOs I know of are relatively fast (for a 4" or larger refractor, f/7 is fast). At this speed, residual false color will easily swamp a diffraction pattern...
I think that Rolando has inferred at least, that star tests of APO refractors are difficult to interpret. I think that he prefers other tests, like the...
The Vixen/Celestron C-102F is from what I understand an APO, and it is not fast at f/8.8 Jim ... refractor, ... a ... it's ... stay ... the ... that...
In case anyone is interested, I have a brand new never used (will flash to latest version if you desire) AutoStar 497 with coiled cord: $134.95. Also, brand...
Hi again! I just thought about a test, don't know if it works or not... What if you were to put some spikes in front of the objective and take an image of a...
Scientists have found away to trace what camera was used to take a photograph.Scientists can now work out which specific camera make and model a photo was...
Having problems with message search?
Fill out this form to ensure your group is one of the first to be migrated to the new message search system.
