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MFR use on Mallincam

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#1 snogum

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Posted 09 January 2008 - 10:29 PM

Dear All

I can see that the true field of view (TFOV) of any CCD will be fixed. I have read some place that the Mallincam Hyper has a TFOV around that given by an 8mm EP, but thats not telling me very much, since I do not know the field of view (FOV)of the 8mm EP.

Can anyone give me an idea of the TFOV of a Mallincam fitted in a couple of different ways.

With 1.25" Nosepiece.

With MFR 3.

Also not really up on the use of Extensions to change the efffective FOV?

Comments welcome.

Clear Skies

#2 rolandskythree

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Posted 10 January 2008 - 01:23 PM

I am not very precise with this, but when I did a FOV measurement test, the 8 mm that is quoted does appear to be close to the FOV that is achievable with a typical Plossl (50 deg apparent field). When I was doing the comparisons, it was with a 1.25 inch configuration on a C8 (I think). No MFRs or extensions were on the camera at the time.

Roland

#3 BradH

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Posted 10 January 2008 - 05:35 PM

Here is a shot of M27 with and without the Mallincam FR. Scope was a TOA 150.

Brad

Attached Thumbnails

  • 2110870-m27 5-22 FR and no FR 28sec.JPG


#4 Mr. Bill

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Posted 10 January 2008 - 06:03 PM

Brad...

How long are the integration times? Is this what it would look like real time on the monitor?

Trailing stars mean unguided images, right? I'm trying to get a feel for what reality is with the Mallincam and whether it would be practical with my Vixen NA140 mounted alti azimuth.

Also, what is a TOA 150 (Tak?) and what is its f/ratio?

Thanks... :question:

Attached Thumbnails

  • 2110912-NA 140_2.JPG


#5 BradH

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Posted 10 January 2008 - 06:27 PM

TOA is a TAK. f7.3 1100mm.

The ob-long star are from the video card in my laptop being 16x9 and the MCH is 4x3. I have problems from time to time changing them back.

On a monitor yes thats what I see plus round stars.

Brad

#6 Mr. Bill

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Posted 10 January 2008 - 06:44 PM

What is the image refresh rate (integration time) of the above images and could I get the same results unguided?

What about faint nebulosity...the surface brightness of M27 is relatively bright.

How would the Veil look like, for example. I would imagine you would have to stack a lot more frames for a similar view and that would mean guiding...right?

Just kicking tires at this point but definitely getting interested in this technology.

:question:

#7 BradH

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Posted 10 January 2008 - 07:06 PM

Bill

I forgot 28sec.

Faint nebulas. It really depends on the nubula. M57 takes less exposer time than M27.

I have seen the Veil at 56sec it shows some detail and color in a 6" scope.

I havent tried stacking frames, but alot of people do and get great images.

I havent tried the MC unguided. Hopefully some else can give you an answer.

Brad

#8 smokin oakum

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Posted 10 January 2008 - 07:58 PM

For what it's worth, I'm testing out my new Mallincam right now in some of the worst conditions I've ever set up my scope in. I'm just trying to get used to all the functions and make sure that I can achieve focus with the MFR-3 and 15mm worth of spacers. I'm going to see if I can nab M42 when I get a window. My tracking is being built right now by Brian at round table, so I'm stuck with only 2.1sec integrations. What I've found so far, is that my scope will achieve focus with all 15mm worth of spacers (using a low profile moonlite), and the MFR-3 giving me f/3 focal ratio, and the cool thing was that when viewing mars the screen refreshed 120X from right to left before leaving the FOV! That was a lot more time on screen than I thought, and it makes getting the object of choice much easier to put on the chip.

Well I'm going backside and see what else I can see without tracking or conditions I wouldn't even bother with usually.

Stay tuned.
Neil

#9 snogum

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Posted 10 January 2008 - 08:12 PM

Here is a shot of M27 with and without the Mallincam FR. Scope was a TOA 150.

Brad


Thanks very much for posting such interesting pictures.

They make it very clear that the TFOV is increased by quite a bit with the addition of the MFR.

I can see that imaging wide DSO's without the MFR will be restricted. Looks like I will add one to my shopping list.

Do you use the 10mm extension rings to increase the effect on TFOV?

Clear Skies
Duncan

#10 snogum

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Posted 10 January 2008 - 08:28 PM

Doing some on screen measurements and looking up the published width of the Dumbell Neb (M27) I get the following results.

Brads setup using MFR the TFOV = roughly 49 min x 38min.

Without MFR TFOV = roughly 27min x 21 min

A significant gain in field of view.

Clear Skies
Duncan

#11 BradH

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Posted 11 January 2008 - 10:00 AM

Duncan I use the 10mm extension.

Here is a shot of M57 taken the same night as M27 was. First with FR second without. Single frames no processing.
Iam not for sure about the exposer time.

Brad

Attached Thumbnails

  • 2112377-1623464-m57%205-22%20FR%20and%20No%20FR%2028sec.jpg


#12 jayscheuerle

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Posted 11 January 2008 - 12:13 PM

Brad, I must say that your captures of M57 are some of the most natural looking I've seen from the Mallincam. No halos or anything. Just got mine today & can't wait to get it out.

Of course, you could tell it came today by looking at my CSC... - j

#13 BradH

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Posted 11 January 2008 - 01:07 PM

Jay you will need to play with the setting to find what works best with your scopes. Start with the recommended settings and start playing.

I know the feeling about the weather. Its been so bad here I have only been out a few time since the AP140 got here.

Let hope for good weather.

Brad


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