Posts Made By: Joe Ramacciotti

Hello Everyone.

I have a question. Will miss-collimation introduce false color in a triplet refractor?

I have a triplet that is not collimated properly and I do see false color. I’ve not really collimated a refractor so before I begin I wanted to see if the level of false color will be reduced as I bring the scope into collimation.

Also, any insight into collimating a refractor would be greatly appreciated.

Thanks.

Joe

Well, I've been away from imaging for some time, but this past Saturday I shot this image of M13. It consists of 9 x 1 minute images along with darks, stacked and processed in Astroart 3, and final tweaks in Paint Shop Pro 7.

The setup used is an APM 130mm CNCII @ F/6, on a GM8 Gemini, and a Canon 300D, all unguided. The FOV is much larger than that shown. I cropped about 50% and enlarged the image by about a factor of 2.

Comments and feedback welcomed!

Thanks!


Joe

Here is my second image for 2008, M57. It consists of 31 x 1 minute images along with darks, stacked and processed in Astroart 3, and final tweaks in Paint Shop Pro 7.

The setup used is an APM 130mm CNCII @ F/6, on a GM8 Gemini, and a Canon 300D, all unguided. The FOV is much larger than that shown. I cropped about 75% and enlarged the image by about a factor of 5.

Comments and feedback welcomed!

Thanks!


Joe

Hello Everyone.

I have a Coulter 13.1” scope and want to change the primary and secondary mirror cells.

The first to be changed is the primary cell, so I’m looking for any suggestions for mirror cells. I’ve looked at the University Optics light weight aluminum cell that is made for the mirror specifically, but I’m concerned with having only 3 support arms and possible mirror sag, opposed to a 9 or 12 point cell.

Also, I would like to keep the mirror captive so I don’t have to remove the mirror during transport with the OTA laid on its side.

As for the secondary, a classic 4 vane spider is what I’m looking for.

Any suggestions are greatly appreciated.

Just so you know why I’m doing so, the current primary wood cell is pinching the mirror and diffraction rings are triangular shaped. The mirror is about ¾” thick and even after 4 hours of stabilization the diffraction patters got better, but still triangular in nature. Not sure if this can be resolved, but though I’d mention it.


Thanks for your help!


Joe

Hello.

I'm in need of some help. I have an APM 80/480mm LOMO lense, a Canon 300D and a Televue TRF2008 focal reducer/flattener. Can anyone tell me distance from the chip to the body of the 300D? I need this distance in order to calculate the spacing between the chip and the reducer/flattener.


Thanks for your help!

Joe

All,

I'm thinking of getting a new DSLR and have 2 in mind; the Canon 50D and the Canon T2i. As for arcsec/pixels go I calculate with my 80mm F6 refractor the 50D @ 2.0, the T2i @ 1.8, and my 300D @ an easy 3.15. With my 130mm F6 refractor it gets even harder: 50D @ 1.24, T2i @ 1.14, 300D @ 1.94.

As I understand it the more dense chips of the 50D and T2i will provide more resolution, but may be at the risk of increased noise, although compared to the 300D it might be an improvement. I like the live-view function and the higher ISO capability, but I am not sure the upgrade will make a significant difference compared to the 300D. Also, I know both cameras have the gapless micro-lenses too.

With all of this said (or typed) my questions are as follows:

It is worth the upgrade from the 300D?
Will I see more noise due to the chip density?
Will the gapless micro-lenses really make a difference?
Although the arcsec/pixels is lower on the 50D and T2i, will it be much harder to image (I have a pretty good GM8)?
If the upgrade is worth it which camera do you recommend?

As for everyday use (birthdays, family, etc) I think either would be fine, but prefer the 50D. Seeing the main reason for upgrading is astro, this carrys more weight.

Any help and insight is greatly appreciated.

Thanks.

Joe

Hello.

I'm looking for some help with one of my Canon 300D DSLRs. The shutter arm broke away from the shutter so the shutter no longer actuates. Seeing the camera no longer takes images as it generates a fatal error due to the shutter staying closed, I'm wondering if the camera would still work if I removed the shutter assembly, or at least the shades. I'd use is strictly for astro-imaging and while inside the camera I'd also remove the IR filter.

Anyone have any experience with this? Any info is greatly appreciated.


R,

Joe

Hello.

I'm thinking of making the move from my DSLR to a one shot color camera. I'm looking for advice on these two cameras; SBIG ST-8300C and the Starlight Express M25C. My scopes will be an 80mm/480mm F/6 refractor and a 130mm / 780mm F6 refractor. I'm leaning towards the SBIG because of the smaller pixels, but the cost difference for the M25C is not a problem if I get a better camera. Does one have advantages over the other?

Also, seeing Starlight does not provide control software I will be using Astroart4.

Any help and guidance is appreciated.

Thanks.

Joe

Hello Everyone.

I have a filter question. I plan to shoot NGC 7000 and would like to know which filter should I use. My setup is an APM 80mm APO with a Televue 0.8x flattener/reducer, and a QHY8 one shot color camera. I currently have the IDAS LP2 light pollution filter, but want to know if an O-III imaging filter would be better. If there is another filter which would be better please suggest it. I will be shooting in Austin Tx, at a site with moderate light pollution.

Any insight is greatly appreciated.

Thanks.

Joe

All,

Here is the first light image using the Orion 6' RC, which is now supplied by Astro-Tech. Overall the scope is an excellent value for the money, and performs quite well photographically given it's "current" price tag badged as an AT. I haven’t looked through it yet, so I can’t comment on this, yet.

Picture Info: M20 8 x 10 min, QHY8, GM8 Gemini guided, Stacked/preprocessed in AstroArt5, Slight post processing and a very, very slight crop in Photo Shop.

The QHY8 has a bias area (for lack of a better term) on either side of the frame when downloaded (left & right), so I did take off a tiny bit of the left and right of the image during the crop. The top and bottom are as they came from the camera. Therefore the FOV is just about what you see in the image. Due to a balance issue I did get motor lag warnings from the mount, which I didn’t correct due to limited time and not wanting to start the whole alignment/imaging process over again, so you can see some tracking error. Also I think the camera is not quite parallel to the scope, yet. Although this is the case, the telescope is winner.

I’m planning another routing the w/e so I’ll pose the second light when I can.

R,

Joe