Do I want to have a body converted for more Ha sensitivity?

[Diane Miller]

Apologies if this is in the wrong forum -- still a newbie here.

I'm making slow progress figuring out processing and finding reds weak.  I'm using a Canon 7D Mk II DSLR and sometimes a Canon 1DX Mk II, with camera lenses.  The 7D2 is mostly now a spare body for regular photography and could be "sacrificed."  I'm wondering how much advantage it would be for picking up more reds to do this conversion to let in more of the Ha wavelength: 

https://www.lifepixel.com/shop/our-services/h-alpha-camera-conversion/canon-dslr-h-alpha-camera-conversion
or:
http://kolarivision.com/astrophotography-h-alpha-and-sulfur-ii-conversion/

Or can I do enough by learning to bring out reds better in processing?  (Or both.)

[pfile]

it makes a huge difference to have one of these things modified.

having said that because of the bayer matrix, 3 out of 4 pixels are wasted when it comes to HA. but if you're going to stick with an OSC a modified DSLR is a good choice.


rob

[msmythers]

Diane

I can't say for that exact camera but here is what I experienced with my Nex-5. These images are from the same camera 2 years apart. Not the best processing in the first but the Ha is not in the image.


Mike

[jkmorse]

Diane,

For the same price as it costs to modify the Canon, you might just find a nice monochrome CCD, with filters, in Astrotrader or elsewhere.  Something with the 8300 chip would be a great next step and even new they are very reasonable.  Rob is right, you are giving up a LOT of data when using a bayered system, especially when talking about narrowband imaging.  It can be done, but you strike me as someone who is looking to go the next step and a monochrome CCD may be the better choice.  Once you make that leap you will never look back.

For what it's worth.

Best,

Jim

[msmythers]

And just to add on to what the guys are saying I would go towards a mono CCD and filters if I wasn't on a very limited budget and other issues. My Nex-5 cost me $125 and I did the mod myself.


Mike

[Diane Miller]

I should think more about a "real" astro camera and filters.  One of my issues is limited acquisition time, between dark and raining dew or the local fog bank rolling in.  I know I can collect on different nights, though.  I think the first thing is to go to a better tracker.  The Astrotrac has its limits. 

I'm thinking about an Orion Sirius.  I know there are many to choose from, but a somewhat portable one would be nice.  Shooting from the house is limited to the north, but we have a decent dark sky site less than an hour away where I can set up next to the car.  And I'm not exactly built like a fullback.  I'm one of those 3/4 scale people and my husband isn't to be counted on for hanging out in the dark unless we're camping under an airplane.  We do that a couple of times a year -- there are several small almost deserted airports in dark areas within a few hours of flying.  So portability is a requirement.

But Mike has convinced me to do SOMETHING!  That's an amazing difference.

[pfile]

check out KBLU - there are a bunch of telescopes up there. one of the astronomical clubs in the area sets up on the tarmac on certain nights.

rob

[Diane Miller]

KBLU as in Blue Canyon airport?  Will do -- is there a web site with information?  (Sounds like you are a pilot?)

A great drop-in place is the tiny Independence airport, between Bishop and Lone Pine on 395 -- high and dry and quite dark. 

[pfile]

yeah blue canyon - i have only heard of it from a friend.

http://hubpages.com/education/Astronomy-at-Blue-Canyon-Star-Parties

also apparently only one real video on youtube, the rest seem to be simulations:

https://www.youtube.com/watch?v=U7M9kSdEcaE

rob

[Diane Miller]

If I go with a CCD camera and filters, can I use my telephoto lenses with it?  (I.e. what adapter?)

With a good enough mount I have 1200mm of good optics, with the Canon 600mm f/4 II and the 2X teleconverter, and it only weighs a little under 8.5 lbs (add 3/4 lb for the 2X).  And an excellent 400mm as well, that can take the 1.4X and 2X converters.

[gvanhau]

Hello Diane
I would not use teleconverters in astro imaging, unless you have a good method to support the camera and the tele lens; the weight of the camera and/or the tele lens introduces flexure that will cause distortions in the image.
Yet, with the 600mm tele lens you already have a good "telescope".

for adapters you only have to search the internet, but it is wise to buy the camera first, to see what kind of interface you need. There are some CCD brands that provide their own adapters to lenses (for example, moravian, QSI, sbig, etc).

Edited: when choosing a CCD camera, you have to take in mind the distance from the lens to the sensor (ie filter wheel and whatever other equipment you put between the lens and the CCD camera, they mut still allow the lens get focus) in Canon lenses this distance is about 55mm.


Good luck.
Geert

[pfile]

i am using an STT-8300M with the 8-position filter wheel. there are two "covers" for the filter wheel - one has an OAG and the other does not. apropos of what Geert said, only the non-OAG filter wheel cover is usable with a canon lens, because the OAG filter wheel cover is too thick by about a centimeter.

so that means i'm limited to an external guider... and that means the possibility of problems with differential flexure.

the other problem is focusing. short of buying or building something like this:

http://store.qsimaging.com/ProductDetails.asp?ProductCode=ACX-BRACKET

you are stuck with manual focusing, which can be a real drag.

there is arduino code floating around out there which can control the focus motors in canon lenses (even has an ASCOM driver), but the challenge there is that you need to somehow connect to the contacts on the back of the lens, which is a real pain.

rob

[jkmorse]

As an alternative, I found a German company (who's name now escapes me) that has a nifty two ring system that attaches to the lens focus ring and the lens body itself that allows for very fine manual adjustments.  I had to buy several for my different lens sizes but it worked nicely.