Grrr, this weather is sooo frustrating. I can't get to complete this thing before moving on. The way my kitchen observatory is arranged, I have to move the setup around to get different objects. Due to cloud, I haven't had a chance to get more data since December. It's begging for a few hours worth I reckon, going by the 24 minutes I've captured here. Despite only 24 minutes, there's a surprising amount of wispy, bloby bits of nebula that pop out.
Pleeze eggscuse the noise, I've squeezed it for all it's worth. Astronomik CLS filter, 8x3 minute subs at ISO400, Kson ED80 @ F5.5, full spectrum modified Nikon D70s, HEQ5 Pro goto, air temp 26C. Got to get a cooler for this camera one day.
Kevin, looking good and I agree 3-4 hours of good data would really make this one pop. Hope you get it, the weather here in Brisbane has been no better no luck at all this year.
Looking good Kevin; it highlights just how much exposure time you
need when working at a relatively low ISO. Just curious, wouldn't
800 have produced acceptable results?
raymo
Ray, the Nikon D70s responds to noise quite differently to Canon and Pentax. From the experiments I've done, for any given exposure it likes ISO 200 and 400 the best. ISO 800 or 1600 actually show less detail, less stars and of course more noise. Having said that, the Nikon at ISO 400 outperforms my Pentax at any ISO, especially at high ambient temperature.
Hi Kevin. Have you tried longer exposures with the CLS filter? If so what were the results? It's interesting that you find lower ISO gives you more detail.
Hi Rowland. Yes, I've found I can go to 5 minutes with air temp in the 20's, maybe longer with air temp in the teens, probably longer in single figures, but I will have to wait for winter just to get into the teens in another 5 months!
At the moment amp glow is too bright longer than 5 minutes. Not that I get 5 minute clear spots between clouds anyway in summer. The joys of living in the tropics, not.
Grrr, this weather is sooo frustrating. I can't get to complete this thing before moving on. The way my kitchen observatory is arranged, I have to move the setup around to get different objects. Due to cloud, I haven't had a chance to get more data since December. It's begging for a few hours worth I reckon, going by the 24 minutes I've captured here. Despite only 24 minutes, there's a surprising amount of wispy, bloby bits of nebula that pop out.
Pleeze eggscuse the noise, I've squeezed it for all it's worth. Astronomik CLS filter, 8x3 minute subs at ISO400, Kson ED80 @ F5.5, full spectrum modified Nikon D70s, HEQ5 Pro goto, air temp 26C. Got to get a cooler for this camera one day.
Good work Kevin!
Looks like you have been hampered somewhat getting more data.
You might have to make a cooler box for your Nikon, at the moment they are only made for Canon DSLR's.
PS, Like the idea of a kitchen observatory, a snack and a tinny always within reach.
Thanks Justin. If I could get a few hours of data it would look good. Not gonna happen. I need an astrophotography system that can get shots in 30 seconds.
Hi Rowland. Yes, I've found I can go to 5 minutes with air temp in the 20's, maybe longer with air temp in the teens, probably longer in single figures, but I will have to wait for winter just to get into the teens in another 5 months!
At the moment amp glow is too bright longer than 5 minutes. Not that I get 5 minute clear spots between clouds anyway in summer. The joys of living in the tropics, not.
Sounds ideal for some moderate DSLR cooling. The benefits of CLS filters seems to be in the longer exposure times.
Yes, even if I could get the camera temp below 20C that would be greatly beneficial. I wonder if I could use the Orion / Canon cooler box and modify it for the Nikon? I need access to camera controls though. I trip the shutter with an IR remote manually but I need access to camera buttons to set this up. On the Nikon, to set the IR remote shutter you have to use 2 buttons at the same time and then it only remembers the settings for a minute or 2 unless it's being constantly used. Or as Justin says make my own. Next problem is I'm getting old and stupid now.
The CLS has something like 31% transmission of total light throughput. As such it likes long exposure times. The benefit is that it still passes 90+% of OIII and Ha so there is a huge contrast boost to nebula while subduing stars. The downside is camera noise increases in the longer subs.
I've been thinking about how to cool my DSLR. The Orion box requires
you to control your camera with a comp. It is also quite heavy. I don't want any more complications than I already have, so I wondered if it might be possible to tape a flexible cold pack around the camera body while leaving the controls accessible. I realise that it is a Heath Robinson solution, and that there would be no control over the temp, but it might
be better than nothing. What the hell, I'm going to give it a try.
raymo
Hey Ray, I'm a big fan of duct tape, string, bits of wood and glue. I call it string engineering. Let us know how you go.
The Nikon D70s has buttons and dials all over the thing, and a lot of the controls require two hands to set, like the IR remote. I don't see how I can cool this thing and still have access to the controls. I think it's too old for PC control.
Hi Kevin, I'll PM you with any results, rather than hijack this thread.
I have no idea whether my 1100D can be comp controlled either, what with being the bottom of the range. I am lucky in so far as all the
controls that I would need to touch during any one imaging run are
on the back. The cold would cut back my battery life, but I have spares.
raymo
Hi Kevin, I'll PM you with any results, rather than hijack this thread.
I have no idea whether my 1100D can be comp controlled either, what with being the bottom of the range. I am lucky in so far as all the
controls that I would need to touch during any one imaging run are
on the back. The cold would cut back my battery life, but I have spares.
raymo
Ray. The 1100D is considered a good camera for AP.
Hi Kevin, I'll PM you with any results, rather than hijack this thread.
I have no idea whether my 1100D can be comp controlled either, what with being the bottom of the range. I am lucky in so far as all the
controls that I would need to touch during any one imaging run are
on the back. The cold would cut back my battery life, but I have spares.
raymo
Yes, the 1100d can be fully computer controlled with one wire, I've tried it out and it works great.
If you can get the temperature down to around 15C the noise is really great. A few years ago I had the idea of putting the camera in the fridge for a while before imaging, but it wasn't and good plan as the sensor fogged up as soon as I took it out.
I don't know how good noise wise the D70 is but I got to compare the D3200 and 1100D the other day in the same conditions and the Canon was Far better.
Thanks for the info everyone. While I'm here can anyone tell me why
when I use the identical process to downsize my images for ISS, some are as somebody else noted yesterday, huge, and in my case, others are
the size I intend. They all start out the same size. My 253 I posted
yesterday looks appalling unless you turn the screen down to 50%, or use
the screen fit icon.
raymo.
Astronomik CLS filter, 8x3 minute subs at ISO400, Kson ED80 @ F5.5, full spectrum modified Nikon D70s, HEQ5 Pro goto, air temp 26C. Got to get a cooler for this camera one day.
