M76 First image

[JKB]

Never tried (or seen) this before. So the other night, clear skies and guiding working nicely, I had a go.

Quite happy with result, smaller than I thought. Not sure focus was perfect but seemed good at start of session: Didn't check collimation either so possibly a little out.

Taken with 150P on HEQ5, Modded 30D with MPCC. ST80 guiding with PHD and Tesco webcam. 12x300s subs, 5x300s dark and 5 bias

As always any comments/suggestions welcomed.

Thanks

Jamie

[Jannis]

Interesting target. Haven't seen this before.

I was wasting probably an hour or more deciding on a target for tonight - but decided to give this one a go also.

My camera is unmodded though, so no idea if it's even any use with an unmoded DSLR on such a small and faint target.

[JKB]

Well good luck. I'm sure you will get something decent. Make sure you post the image. Cloudy here!

Cheers

Jamie

[Jannis]

I will for sure post it!

I'm struggeling a lot with my tracking though. Even though PHD graph is OK, 50% of the 300s subs have egg-shaped stars, if not worse. Not sure if the end result will be good at all like this. I'm barly able to see the fain "wings" in the subs. I don't see even remotely as much red as you do with your modded DSLR though.

[JKB]

Your guiding looks pretty good. You can see a lot more stars than with my cheap webcam!

I had a similar problem a while back and it was due to a little 'play' in the mounts DEC axis. quick tighten up and much better. Also I encountered problems whilst running EQMOD as I hadn't set the amount of guiding correction quite right. All good now though.

Look forward to seeing the final image.

Cheers

Jamie

[Jannis]

Yeah, the guiding graph looks OK. I think it must be that in that area of the sky, the scope is put in a position where it's very well balanced, so nothing is "holding back" the play in the gears - like you said.

However, i did some adjustments in PHD, and it seems to have increase the guiding more then just "a bit", even if the curve looked roughly the same. I went from about 3 of 4 pics with eggy stars to about 1 of 4.

I changed camera gain fom about 40-50% down to 12% (hate that it requires restart of PHD, silly QHY settings). Then changed calibration steps from 3 to 1 sec. And also set exposure to 1 sec instead of 3.

Surpricingly, lowering the gain to 12%, and lowering the exposure from 3 to 1 sec more the doubbled, nearly trippled actually, the same guide star's S/N ratio...?! o.o

I wonder if i might have better guiding if i go for a barlow on the finder to guide at 400mm, but then i'll be at F/10, wich i'm not sure if the QHY5L would like very well.

I'm currently loading the stuff into DSS. May i ask what stackign method and settings you used, if you remember? Just curious.

[Daniel-K]

theres something not quite right with that graph the ra and dec should just be crossing over and there not there kind of bouncing of each other and then every so often crossing over i think thats were your losing your subs. this is what my graph looks like on an average night

[Jannis]

Now that's a smooth line. But you have DEC guiding off, or is your tracking simply that good? o.o

Yeah, i'm used to it going up and down as well, so i found it a bit odd too. Though, after adjusting the settings, i had better guiding and nice round stars. But can backlash alone cause a graph like that?

Though this is a bit off topic i guess. n_n"

[JKB]

Hi Jannis

I stuck with median for all

Cheers

Jamie

[cfpendock]

Hello Jannis. Your stars look round to me, so I think the guiding is OK.

Please correct me, but I thought the ST80 was already 400mm? I use one for guiding and I certainly wouldn't want to go to a longer fl.

Chris

[Daniel-K]

no my dec isnt off just very well balanced. i have it a little heavy on the east side. make sure your guider is well aligned to your scope aswell and when choosing a guide star try and pick one in the middle. HTH

[Jannis]

Hello Jannis. Your stars look round to me, so I think the guiding is OK.

Please correct me, but I thought the ST80 was already 400mm? I use one for guiding and I certainly wouldn't want to go to a longer fl.

Chris

Hi. I think you're mixing me with someone else here now? As i haven't posted a pic of my star yet. Only a screenshoot of PHD.

I use my finderscope for guiding, not the ST80.

I have anotehr suspect though - i use the original finderscope holder for guiding. You know, the one with an O-ring around the scope, then 2 adjustable screws and 1-spring instead of teh 3rd screw.

no my dec isnt off just very well balanced. i have it a little heavy on the east side. make sure your guider is well aligned to your scope aswell and when choosing a guide star try and pick one in the middle. HTH

I see. Very good tracking then i must say. I haven't had any guiding issues yet since i got my new guide setup exept yesterday. My scope is at the max of what i can balance, so i can't really do much to improve it without buying an extension shaft for my mount. Both 5KG counterweights are as far out as they can get - and my scope-side weight is about 10.5-11kg. >_<

[cfpendock]

Sorry Janis! A (frequent) moment of confusion.....But I agree with what you say about the finderscope fixing. I would have thought this was always (of necessity because of the spring) too flexible for accurate guiding.

Daniel-K - I agree with what has been said about your guiding. This is the kind of trace I dream about. If that is an "average" night, please don't show a "good" night. Well, I suppose it would be two straight lines! What fl are you using for guiding? And I presume this with periodic error correction?

Chris

[Quatermass]

Thats an interesting target never seen it before but it looks pretty neat, will have to give it a go next chance I get. Nicely captured.

[Daniel-K]

Daniel-K - I agree with what has been said about your guiding. This is the kind of trace I dream about. If that is an "average" night, please don't show a "good" night. Well, I suppose it would be two straight lines! What fl are you using for guiding? And I presume this with periodic error correction?

Chris

hey chris no periodic error correction just reduce the flex by using a losmandy dovtail FL is 800 i think or 1000 its the 150pds