Roll-Off Roof Setup - Night time 1st Test Run

[Raymond TSE]

I have done 20 odd 2- min unguided exposure of NGC3628 and have stop when this target is about 72 degree high.

Then I tried M51 with autoguide. The guidestars were way too much off-focus and the guide stars have spread into a square of 3-4mm wide.
PHD was still able to calibrate and track with RMS about 0.28 to 0.48 depending on seeing.
Then I autoguided M51 successfully for about 10 odd guided exposure of 5-min each.

Next time I shall re-focus the Lodestar manually, so that I could use dimmer guide stars (too defocused to see at all).
I could see only 2 defocused brighter guided stars last night for 980mm main scope.

The biggest challenge, was go-to. The T-Point model with 10 odd mapped stars still showed great discrepancy.
Sync stars would not be a problem since the electronic finder (8 x 5 degree) could always locate the stars after slewing.

But for small & faint nebula, the electronic finder was too big and could not see them even in 10 sec exposure.
Thus go-to has become a matter of guess work for the small imaging FOV of 32 x 24 arc sec.

Remote imaging's biggest advantage is to give me some free time at home with family members.
They just treat me as if I am surfing in front of the computer and not away from home .

Raymond

[社長]

For 5min subs, I only do unguided exposure, Paramount is good enough for that.

With STi on my modified 9x50 finderscope (f3.5), the whole M31 and Horsehead nebula can be seen from 5 second exposure with reasonable S/N ratio.

[Raymond TSE]

For 5min subs, I only do unguided exposure, Paramount is good enough for that.

With STi on my modified 9x50 finderscope (f3.5), the whole M31 and Horsehead nebula can be seen from 5 second exposure with reasonable S/N ratio.

5 min subs is for testing only and to avoid losing guide-star since the S/N of defocused guide star is quite low. If the Lodestar's focus has been adjusted,
I believe that PHD should have no difficulty to guide up to 15-30 min subs even for moderate-grade mount EQ6 Pro.

Focal length of 50mm x f3.5 = 175mm. Yes, I think EF50mm F1.4 focal length might still be too wide as electronic finder, and only suited to bigger DSOs.

Perhaps I shall change it the lens to EF135mmF2 instead to give more narrower FOV of small DSO such as NGC3628/M51 (small objects around 10-15 arc min).

My ED80F7.5 (reduced to F6 after 0.8x reducer) has given me medium FOV in the past. Thus TEC 140F7 is more suited to medium to small objects.

[社長]

if you are going to use ACP, then you have to get rid of PHD guide.

I would avoid using camera lens as guiderscope - too many movable parts in the optical chain, hence higher chances for flexure, also the star sharpness is far behind a cheap finderscope. Through my modified 9x50 finderscope with two 2x barlow stacked plus an TMB Supermonocentric 4mm eyepieces, I can see belts on Jupiter, also round airy disk and diffraction rings on bright stars.

[Raymond TSE]

Dear Savio,

The camera lens EF50mmF1.4 (5 x 8 degree wide FOV) (to be replaced by EF135mm F2) is not guidescope.
It is only an electronic finder to correct the incorrect go-to, since the incorrect go-to would
bring the target off my main imaging Atik314L (narrow FOV 24x32 arc min) but will still be covered by the
electronic finder. Then I can make mount movement to centre the target.

Of course, the lens setup with ST402 could be used as a guidescope.

Since I have Lodestar as Off Axis guiding camera guiding at 980mm, the mount's guide port has already been
occupied by Lodestar's guiding cable to the mount EQ6 Pro. Off axis guiding avoids most issues with flexure.

When I later start to use SX AO, then the mount guide port would be used by the AO out-port instead of Lodestar's guide cable.
Thus, the mount cannot accept any more guiding cable from ST402 at all.

ACP/CCD Autopilot/CCD Commander ? Would consider in the next move.

ME2, on the wish-list. When will the price be adjusted ? Any information you can get before the price is announced ?
Since EQ6 Pro is just working on remote operation, I want to stick to EQ6 Pro for a while before upgrading.

Raymond

[社長]

Dear Savio,

The camera lens EF50mmF1.4 (5 x 8 degree wide FOV) (to be replaced by EF135mm F2) is not guidescope.
It is only an electronic finder to correct the incorrect go-to, since the incorrect go-to would
bring the target off my main imaging Atik314L (narrow FOV 24x32 arc min) but will still be covered by the
electronic finder. Then I can make mount movement to centre the target.

Of course, the lens setup with ST402 could be used as a guidescope.

I have SBIG efinder assembly for ST402 in stock, a 100 f4 lens

ACP/CCD Autopilot/CCD Commander ? Would consider in the next move.

I am using ACP which definitely worth the money.

ME2, on the wish-list. When will the price be adjusted ? Any information you can get before the price is announced ?
Raymond

To be honest I don't know, now the promotional price for MX will be ended on Mar 15th.

viewtopic.php?f=9&t=3506

[Raymond TSE]

While the use of On-axis for RA for ME II is understandable to enhance pointing to 5 arc sec and to eliminate PE,
what is the use of On-axis for Dec ? Just to enhance pointing ? Or to achieve similar effect of Dec guiding ?

Raymond Tse

[Raymond TSE]

After consulting with experienced astro imager yesterday afternoon, I realize that my goto routine was too simple and sometimes naive,
since I did not use plate solve to center the imaging scope.

The T-Point mapping previously done and EQ6Pro's goto is still rubblish.
I wasted the whole night last night but could not center my DSO.

I have to disemble and revise/re-engage the whole gears again.

Any person has a good suggestion for a very sensitive/sense-up version of Network Cam (no IR LEDs but fast frame of about 5-10 fps)
which can enable me to monitor the mount in near darkness as surveillence cam in the observatory ?

Both my Sony PoE Netwok Cam and Logitech web cam see nothing at night.

My Gstar2 sense up camera (128x sense up)
can see everything in near darkness but its refresh rate is too low to monitor the moving mount. Just ok for slow moving sky clouds.

The danger of the rear of the scope hitting the mount is always a risk,
but I have no way to check during remote operation before I set the mount limits.

Raymond Tse

Raymond

[Raymond TSE]

Just try 10 min autoguiding M51 by PHD. The Dec side of the scope is not balanced as the front of the scope is a bit heavy.

Autoguiding result is still acceptable though not perfect.

Raymond

[Raymond TSE]

Single capture 10 min autoguided M51. No dark or flat.

[社長]

While the use of On-axis for RA for ME II is understandable to enhance pointing to 5 arc sec and to eliminate PE,
what is the use of On-axis for Dec ? Just to enhance pointing ? Or to achieve similar effect of Dec guiding ?

Raymond Tse

don't understand your question, On-axis what?

[社長]

After consulting with experienced astro imager yesterday afternoon, I realize that my goto routine was too simple and sometimes naive,
since I did not use plate solve to center the imaging scope.

The T-Point mapping previously done and EQ6Pro's goto is still rubblish.
I wasted the whole night last night but could not center my DSO.

I have to disemble and revise/re-engage the whole gears again.

Any person has a good suggestion for a very sensitive/sense-up version of Network Cam (no IR LEDs but fast frame of about 5-10 fps)
which can enable me to monitor the mount in near darkness as surveillence cam in the observatory ?

Both my Sony PoE Netwok Cam and Logitech web cam see nothing at night.

My Gstar2 sense up camera (128x sense up)
can see everything in near darkness but its refresh rate is too low to monitor the moving mount. Just ok for slow moving sky clouds.

The danger of the rear of the scope hitting the mount is always a risk,
but I have no way to check during remote operation before I set the mount limits.

Raymond Tse

Raymond

efinder 幫你把第一顆星導入主攝星鏡的像場內是很實際用途的，之後便應用主攝星鏡去做T Point，一般來說做夠同一天區內的6個T Point，運算模型便成立，指向精度便會明顯提升，便可以移至鄰近天區再做幾粒，按理你的做法沒問題

另外EQ6在GOTO情況下，到中天便自動停機，又或者軟件都可設定，沒有危險的，是因為連接了其他軟件之故?

所以我常跟人說，若不是經常拍些很難人肉找出來的目標，不用GOTO可能更好，一來省電二來可以在中天前後即最佳拍攝時機一路拍下去，我在合歡山上拍深空時，好幾次相機只淨下數毫米便撞到三腳架上才停機的，例如NGC6960：

viewtopic.php?f=17&t=442

[社長]

Single capture 10 min autoguided M51. No dark or flat.

可塑性很高的M51，Raymond 好波!!

給有志在香港弄遙控天文台的愛好者又一枝強心針。

早兩天下班後幫一位朋友弄他的APM 203 APO + Paramount ME，我也鼓勵他在自己的天台試試實現一個簡單的遙控配套，至少拍深空時不用整晚坐在鏡旁守候著。

[Raymond TSE]

Single capture 10 min autoguided M51. No dark or flat.

可塑性很高的M51，Raymond 好波!!

給有志在香港弄遙控天文台的愛好者又一枝強心針。

早兩天下班後幫一位朋友弄他的APM 203 APO + Paramount ME，我也鼓勵他在自己的天台試試實現一個簡單的遙控配套，至少拍深空時不用整晚坐在鏡旁守候著。

Star imaging is no longer a single person event. Just setup after dark. Diner with family. Watch tv etc.
Previously each image outside is about 1 hr exposure in total. Now thinking about 10 hrs each when you can
Save ard 2 hrs exposure each night , such as during this week.

[Raymond TSE]

While the use of On-axis for RA for ME II is understandable to enhance pointing to 5 arc sec and to eliminate PE,
what is the use of On-axis for Dec ? Just to enhance pointing ? Or to achieve similar effect of Dec guiding ?

Raymond Tse

don't understand your question, On-axis what?

Sorry for the too abbrevated question.

On Axis encorders, new feature of ME II available in mid 2013 but expensive at Usd 3000 per axis.

[社長]

Single capture 10 min autoguided M51. No dark or flat.

可塑性很高的M51，Raymond 好波!!

給有志在香港弄遙控天文台的愛好者又一枝強心針。

早兩天下班後幫一位朋友弄他的APM 203 APO + Paramount ME，我也鼓勵他在自己的天台試試實現一個簡單的遙控配套，至少拍深空時不用整晚坐在鏡旁守候著。

Star imaging is no longer a single person event. Just setup after dark. Diner with family. Watch tv etc.
Previously each image outside is about 1 hr exposure in total. Now thinking about 10 hrs each when you can
Save ard 2 hrs exposure each night , such as during this week.

對，有了遙控天文台，便可以向一些以打游擊來說永不可能實現的目標進發，若是打游擊+好天空，或遙控觀測站+普通天空，我不一定選前者。幸好我現在是遙控+好天空。

P.S. 我已訓練到自己一手抱B餵奶、一手用鍵盤下指令在西藏攝星，或到洗手間一手忙其他一手用提電話修定西藏拍攝指令

[社長]

While the use of On-axis for RA for ME II is understandable to enhance pointing to 5 arc sec and to eliminate PE,
what is the use of On-axis for Dec ? Just to enhance pointing ? Or to achieve similar effect of Dec guiding ?

Raymond Tse

don't understand your question, On-axis what?

Sorry for the too abbrevated question.

On Axis encorders, new feature of ME II available in mid 2013 but expensive at Usd 3000 per axis.

按有經驗人士指出，若用上一些大鏡，雙軸編碼比單靠T Point軟件修正，指向精度會高得多的，當然一般大視場業餘拍星影響少些。

[Raymond TSE]

Lucky this week with almost 7 clear nights from Monday to Sunday.

After solving the goto question on Wed 06-03, I was able to collect 5 consecutive days of photos from Wed up to Sun nights.

Already gathered 3.8hrs of L frames for NGC3628 and 6.5hrs of L frames for M51.
RGB & Ha for M51 to be done later.

Very pleased with this kind of efficiency for imaging session up to 2.30 am odd each night.
No need for all night through.

With automated imaging software, the efficiency/photo quantum could further be extended.
Cool !

Raymond

[社長]

期待你的首張完成作

在香港能拍上一張總曝光10小時以上的LRGB照片，真的沒太多機會，也沒太多人能持續這樣做。