I hate my Meade DSI

[Mel]

Yes, I know, many people have them and yes, I know, many people have got 'good results' from them - but I've yet to meet any of them!!! :wave:

I have owned my DSI Pro II for just over 18 months now and now I am officially fed up with it. Here's my (latest) problem with it.

I want to image using my Canon DSLR thru my Megrez90 which is piggy backed on my LX200R. To do this, I have drift aligned the Meade (3 minutes or so of stable star) and wish to autoguide (have turned off PEC for now) with the DSI thru the LX200. So far so good.

The one issue I now have (apart from the drivers insisting they re-install themselves each time the damn thing is pugged in) is getting a decent guide star onto the tiny chip at 2.5metres of focal length. So, thinking I was being wise (sigh...) invested in a cheap 2 inch flip mirror (30 quid, astro fest this year - bargain!) to help centring of any guide star on the DSI. Can I get the blo**y thing parfcocal with any of my (quite extensive colection of) eypieces? Can I h**k....

So basically what I am figuring I need now is an (approximately) 1.5-2cm or maybe 1 inch long 1.25" diameter tube extender and am just about to start hunting one down. Unless anyone has any suggestions?

I'm just sharing this to see if anyone have similar fun with their DSI 'Pro' II or similar? :crybaby:

Iain

[centroid]

Don't despair Iain, it can be done!!

I used a DSI-C, as my guide camera, for a couple of years, on both the ED80 (guiding the LX), and on a 10" and 12" LX (guiding the ED80).

If you take that using the DSI is someting like using 6mm eyepiece on your 10" LX, you can see that your DSI is seeing a very small FOV indeed. This would make it difficult to locate and centre a star to guide on. It can be done, as I have used my DSI, and now Lodestar guide camera, directly on the 12" LX200R, which has a focal length of 3048mm. Not saying its easy mind, but not impossible.

You would be far better to use a Focal Reducer on the LX, say an f/6.3, or even f/3.3 will still give you adequate guiding accuracy. This will make life much easier for you.

You will also find that when using the LX as a guide scope, the agressiveness of the guiding software needs to be backed off from where you have when using the 90 to guide the LX.

HTH.

Dave

[Mel]

Hi Dave,

Thanks for your reply, and yes, I know it can be done, it's just sooo frustrating.

I have got some (semi-) decent results from the DSI using it standalone before. This was a year or so ago when and my LX was mounted AltAz while I was waiting for the wedge. Come to think of it I have not really fired up the DSI + Envisage for a while now, may give that another shot if I get the time. I have learnt from experience that that piece of software can do an awful for lot for that particular cam.

With respect to guiding, I am still on the start of the curve, I got it working in Jan this year (with the DSI thru the LX), and managed several 2 minute exposures of Pleides - no shortage of guide stars there . But then my scope was ooo for about 6 months while waiting for a replacement Autostar II handset (frost damage or bad contacts I reckon) and I have just got round to trying again. Long summer days and light pollution mean that it's nigh on impossible to image where I live unless it's the middle of the night, and family/work commitments usually rule that out.

One thing I've learnt is to choose a target situated in/near a nice field of relatively bright stars. I randomly picked the globular cluster M2 out as a target recently and had a load of trouble guiding on it - found out afterwards it's welll known for sitting in a sparsely populated region of the sky!!!

Thanks alot for your comments - it's all useful!

ATB

Iain

[philipok]

Hi Iain,

I read your post and noticed you had autostar problems - I've just sent mine back to Telescope House, as the LCD kept fading in and out.. was that what happened to yours?

Also my microfocusser has failed, so that was sent as well

hopefully they'll get them back to me in the next week or so..

As for the DSI, I've had one for 2 years (II C), but have taken *one* picture - saturn ! I just think I may have wasted money on it.. have you used it for pics?

Cheers

Philip

[Mel]

Hi Philip

Yes, that does sound similar - I also had the following:

1. Spurious characters appearing, including some space invader-type graphics - an ASCII face was definately in there somewhere!

2. Screen fading in and out

3. Screen staying blank (with background red LED lit)

4. Characters producing a letter e.g. up arrow = N, down arrow = S etc..

5. Runaway motors which would not stop until say 10-15 seconds of not touching the keys. Yikes!

All in all I was (read am) not impressed - I will PM you with the PM (no pun intended). :laughing3:

Iain

[RobH]

Hello Iain,

I use a DSI pro, not pro 2, as my guide camera and this has an even smaller chip.

I've never had any trouble with it!

I have a 1 1/4 inch antares focal reducer that I screw into the end of the nosepiece to bring the focal length down to a reasonable figure when I'm using the 14 inch as the guidescope and use PHD as my guide software.

I've heard that some people, when using, for example, Maxim, as the guide software, have had trouble finding guide stars with a DSI, but after switching to PHD with the same camera, no longer have the problem.

Cheers

Rob

[Mel]

Thanks Rob,

Of course, the clue is in the name - 'Focal Reducer'.

I am going to try an eyepiece barrel extender then may look round for a cheap 1 1/4 FR if no luck. Thanks for the nudge.

I use Maxim (or have been), but I know there are several alternatives out there - may well give one of those a go. The alternatives I have heard of that come to mind are PHD and GuideDog.

Iain

[Psychobilly]

I use My DSI II C as my guide cam on the CPC800 and usually use a f6.3 reducer as well no probs finding guide stars with PHD guide and usually only have to use a maximum guide exposure of 2s frequently getting away with 0.5s

Billy...

[Mel]

Well, many thanks to Steve from FLO who kindly posted me (completely foc - service or what? :hello1: ) a barrel extension which has helped to make the DSI parfocal with a 26mm ep in a flip mirror assembly. Had a play last night and got it picking up mag 5/6 guide stars with relative ease.

Only problems I have now are:

1. DSI misbehaving in Maxim when calibrating guiding - it complains it can't find the guide star in every frame, even if it draws all the lines showing it's movement. Sometimes it puts a X=0, Y=0 which indicates it cannot locate the bright point. I'm sure this is down to the quality of the image, as there's always vertical jagged lines which I think are caused by extraneous light from LEDs, handset etc.. and allowed into the chip by the extraordinary bad design of the camera. Will make various changes to try and improve that.

2. USB issues. I am using a USB 2.0 (hah!) hub atm and having nothing but trouble with it. It always seems to be a different issue when I come to use it - i.e. had everything working fine, labelled the wires/slots etc then next session, nothing works - even the hub light stayed out when I plugged it in first time last night! Can anyone recommend a USD 2.0 hub that works? I'm plugging the following in to mine - a Kensington) - DSI, Scope via Serial to USB adapter, Canon data cable, shoestring DSUSB shutter control.

3. Short exposures of the DSI can really confuse Maxim - anything sub second seems upset it.

My next step is to try another guide program - alot of people have reported PHD to be a worthy alternative, so I will try that next.

Thanks guys for the continued help/support - it really is appreciated! SGL rocks!

Iain

[Psychobilly]

is it a powered hub?

I use a powerd hub and can get away with a 1.5A PSU if all i'm using the DSI II C, GPUSB and DSLR data lead with one externsion lead in place but I use a 4A psu if I am using both the DSI II C and DSI I C through the hub and extension lead...

If I'm only the lead that came with the Hub then I can get away without using the DC adaptor at all.

Billy...

[SteveL]

seconded on the powered hub issue... even my DSI Mk1 will use all the power from a single USB socket. If I used it on an unpowered hub and plugged something else in, the USB port powering the hub will shutdown, or the DSI became flaky or stop responding.

[Psychobilly]

The II's are a lot more powere hungry than the I's when i used both together its uually teh II That suffered it kept disapperaing and re-apperaing on the laptop changing to a bigger PSU for the hub sorted it all out.

The hub I use came from maplns it came with a small dc adaptor (either 1 or 1.5A) but as I said Ihave added a 4A unit to the kit justy in case i want to run a couple of power hungry devices...

Heres a link to the hub

http://www.maplin.co.uk/Module.aspx?ModuleNo=46350

[Mel]

Guys

Good news, got my usb troubles sorted thanks to a PSU - should've known it was a power issue, I was on batteries the other night which I think was the cause of the problems - my setup was usually ok on AC power to the laptop. A 4.5v DC adapter to the USB seems to have helped . Also got my DSI guiding - will post any results I get out of humility if nothing else. Got 1,2 and 4 mins subs of M57 and M27 tonight which is ace.

Cheers for the support and advice - seems to have worked in this case!

Iain

[Mel]

Another update is required - I no longer hate it - in fact I am starting to like it quite a lot!

The problems that have been solved were:

1. Power - got a 5v 2.5A psu from Maplins - sorted ALL my usb issues.

2. Getting a guide star and calibrating - using the simple auto dark in Maxim helped enormously and making sure the sliders are set to show up the stars made a big improvement (made it work basically).

3. Parfocalising - was fixed by using an ep of about 9mm on the Meade right angle that came with the LX200 - it's exactly the same fl as the DSI!

Next on my list is to try PHD (if Maxim ever lets me down again, which it's not atm) and a 0.63 FR to improve the field.

Many thanks again guys!

Iain

[Psychobilly]

Hi Iain,

I'm glad you stuck with it and have worked through the issues and are now guiding.

Billy...