I have looked all these wonderful DSLR camera pictures posted here and I finally decided to get in on the fun. I just purchased a Cannon EOS XSI. I have been playing around with all the functions to get a feel for it. The camera is very intuitive and I think I am gonna really like it. The remote software that came with it is nice to and the live mode is awesome. I have a question though about the software that most of you use to really optimize the long exposure setting (manual - bulb)? The software that came with it seems to end at 30 seconds no matter what. I looked at the MaxIm DSLR software and don't know if I want to spend half the camera's price to control a shutter! What are some alternative recommendations? If I must I will purchase whatever is necessary. Thanks for any input.

JJ 

John:

You will get much more than shutter control with MaxIM DSLR. The live mode on your camera will help greatly with focusing, but there's no substitute for using a full-screen, full-res image for that as well.

One of our 3RF volunteers just bought the same camera and I'm looking forward to seeing it. I know there are shutter-control hacks out there in freeware land for the Digital Rebels and the 300s, but I don't know if they'll work with the new camera. One thing he told me about the live mode is that you can magnify it greatly, so that will help, too.

With a manual B (bulb) setting, you can let the exposure go as long as you want. You get noise buildup, of course, but that's the nature even of cooled CCDs ... the longer you go, the more noise you'll get.

My camera (a Pentax) uses battery power to keep the shutter open, so it drains the two batteries quickly, especially in cold weather. However, an AC adapter solves that problem neatly and is a highly recommended accessory for DSLR users.

One thing to keep in mind about long exposures with a DSLR is that downloading an image from the CCD to the memory chip will heat up the chip and other electronics, adding to pattern noise in a subsequent image. For that reason, it's advisable to let the imager chip "rest" between exposures a time at least equal to half the exposure time. It's also advisable (after you've finished using it for focusing) to turn off the mode that automatically displays the most recent image (or other info) on the camera-back LCD display (which also heats up the camera electronics, adding noise to subsequent images).

Thanks Chip for the info,

I also ordered the orion t ring and the adapter to go to a 2" focuser. Orion # 5224 and adapter # 5269. Are there any other adapters I must purchase? I really want to to use this unit on my 20" Obsession with the Feather Touch focuser.The feather Touch is not threaded at the top like the typical Orion focuser. I have added motor focus to  the focuser in anticipation of DSLR imaqing about a year ago.

Motor Focus 

JJ 

I have not actually tried using a DSLR with any of 3RF's Obsessions, but some F4.5-ish scope owners have trouble reaching focus due to lack of in-travel.

If you have the low-profile FeatherTouch you may be okay.

If you can't reach focus, and you don't want to shorten your truss tubes, you can try using a barlow. GTO makes a Proxima 1.5X 2-inch barlow that is pretty nice. That is what I used in my F5 newtonian to get my 35mm camera to focus. The front flange of FT focusers is threaded for 52mm filters, so you might also be able to use a screw-on barlow by attaching it there.

I don't know if removing the eyepiece retaining screws will buy you additional in-travel ...

I have been wanting to try some lunar imaging with my DSLR and one of 3RF's big Obsessions, but have not had the time. I will be out there a lot more in the coming months and that is one thing I will be doing.

Chip

I do have the low profile Feather Touch focuser. Also at tis time I have my primary collimating screws backed all the way out. I can screw the primary mirror in about 3/4" to the other end of travel. If necessary I can have another set of truss tube made for astro imging. I would refuse to cut my current tubes. I know JMI would make me some.

JJ 

 For longer exposure control and the number of exposures I use this program

DSLR Shutter  For instance you can set it to take 20 exposures of 2 minutes with a delay between each image to allow the chip to cool off. I am not sure about your camera but it works with these remote cables. Hap Griffin Astrocables.  Most cables are an IR remote control for the shutter. You put the camera on the "bulb" setting, then with the DSLR Shutter program runniing it will trigger the remote which will open the shutter of the camera, it will then send another signil to close the shutter after the programed amount of time. It will then wait the set time between frames. It then repeats the process for the number of images you set it to take. If your camera has the "mirror lock up" feature it can also lock the mirror up before trigering the exposure to reduce camera shake from the mirror movement.  I have a Nikon D-40 and everything works just as advertised. I also have a program (Nikon Camera Control) that automatically downloads the image from the camera to my laptop for viewing  which can be done while the next exposure is being taken. You can even write a script to take a series of  long and short exposures if the target needs both. Best of all it is free. I am sure MaxIm DSLR is a wonderfull program with many more features and controlls but to start off with and get the feel of imaging you can try DSLR shutter then if/when you need a more powerfull tool try MaxIm DSLR.

TheHarvester,

Thank you for the links. I downloaded the DSLR Shutter and am looking forward to trying it out. As usual, get a new toy and the weather goes bad. Cloudy, rainy,and windy here now. 

JJ 

 Your welcome.

Now you know you don't need clear skies to learn how to use it. My first set of images using the software and cable were of my bedroom. 

Its been raining and cloudy here for days now since I got this camera of course. It has given me time to play with the software that came with the camera. Seems I do not need the remote fob. It has a timer setting in the software so you can set the interval between shots and the number of shots and time duration up to 99.99 minutes! You set it up and let the camera do it's thing. How sweet it is. I do need to get a power supply though if I will be operating it for extended periods. Also came across a really cool, cooler for it to. Don't know if it will fit the XSI though.

http://www.centralds.net/en/products-x.htm#excooler 

I have different question ref Canon XSI: Pre-release discussions pointed to a possible higher background noise of the 12 MPix CMOS of the XSI in comparison to the Rebel (or 400D in Europe).

Do you have any comparison or coments on that issue as you are one of the first 450D owners I come across?

Thanks and Clear Skies

ngc2438

I was not aware of of a higher noise level. I guess I should have researched a little more. I have not taken any long exposures as of yet. I am looking on receiving the t ring and 2" adapter soon. I will let you know what I find out about noise.

As to noise, I took some dark frames and then some long exposures through the lens.

 Noise is very minimal.

Hi John, 

No reason yet to get frustrated - it was only word by some serious photo-whiz in a German foto-community page that I open occasionally. The experts suggested that the smaller size of the pixels would have slightly negative implications on noise reduction. So far I have not detected any test reports yet, but that stuff will come soon.

In case you are into daytime photography as well: I can highly recommend you to replace the Canon standard 17-55 lens (f4.5 - 5.6) with the Sigma 18 - 50 f2.8. I use that lens on my Canon 400D and it is wonderful in terms of color correction and shows very little darkening in the corners. Sharpness is generally very good. If you like, I can post a few of my own test picture field selections here. The Sigma comes for around 400 USD, that's half of what the 17-55 f2.8 Canon costs!

Clear Skies!

Try taking a series of long exposures first then your dark frames. That is when you will start seeing noise in your darks. Take about 5x 30sec light frames with 30sec delay between each exposure. Then take one or two 30 second darks, you might see some noise then even when the image has been resized.  Taking the dark frames first before the chip has even had a chance to warm up won't really give you an accurate idea of the noise level.  

BTW, someone above recommended trying DSLR Shutter to control the camera.  That won't work with the Canon EOS camera unless you buy the adapter cable as specified on the web page. But If you got anything like I got with my EOS 350D you won't need that. The camera came with a USB interface cable and the needed software to capture images remotely using a laptop or PC.   But if you want to use that while using it in Manual Mode with exposure time set on (B)ulb you will need the remote switch. 

Have A Nice __________

Just received my 2" to tring adapter from http://www.cncsupplyinc.com/ on 6/5/08 and was not able to try it till a public event in down town Sioux Falls. We had 89 people stop by and I was able to get8 exposures at 30 seconds at ISO 1600 Through a 120mm Orion refractor at F 16.6. (2 x barlow). This is my first DSLR shot. It took a little bit of experimenting to get the settings right but I finally got it. Shot M13.

i use my camera as stand alone, so i cant advise on the software, focusing should be easy enough on a fairly bright star, zooming in the whole way and using a magnifying glass was all i ever found neccesary for pin point stars, i  dont use dark frames either, the camera's noise reduction is pretty decent already- stacking more subs (light frames) works better for me- on extended exposures ill  take a series of 800ISO, turn the camera off a minute or so to 'cool'- then take a few 1600ISO, then repeat with the procedure using 200-or 400ISO- the only i see bad about the camera is the built in filter cut-off

tasco-60mm:

i use my camera as stand alone, so i cant advise on the software, focusing should be easy enough on a fairly bright star, zooming in the whole way and using a magnifying glass was all i ever found neccesary for pin point stars, i  dont use dark frames either, the camera's noise reduction is pretty decent already- stacking more subs (light frames) works better for me- on extended exposures ill  take a series of 800ISO, turn the camera off a minute or so to 'cool'- then take a few 1600ISO, then repeat with the procedure using 200-or 400ISO- the only i see bad about the camera is the built in filter cut-off

I don't use the automatic noise reduction; instead I prefer to take some darks every know and then while I am taking the light frames just so I can get some darks when the ambient temperature is relatively close to the same as when I take the light frames. Then I'll take a bunch more darks at the end of the session so I'll have at least half as many dark frames as I do light frames,  I do allow the camera to sit idle and cool between each shot, length of time depending how long the shot was.  If you don't allow it the camera to cool the lower corner of your image will be red from heat noise created by the battery power adapter.

Using the built in noise reduction is fine when your imaging something bright like a star cluster that you won't be spending the whole night on.  Automatic Noise reduction can be very time consuming taking away valuable time that could be used capturing more light frames (image data). 

Note: When shooting darks of different exposure times (and or ISOs) you have to force DSS to believe they were all shot the same amount of time.  If you don't DSS won't use all your dark frames and the resulting image could still have lots of noise.

Have A Nice __________

i mean i dont use the camera's noise reduction either- i just dont bother with darks at all- ill be honest about it (bad remember here)- if i take 16-30 light frames and stack them- the noise is pretty much gone- i tried darks before - 1 out of every 4 shots i think, i really didnt see much of an improvement- but i did think i lost stars that way- like i say though, its been a long time since i took darks- maybe ill try next time and compare stacking with and without them