Adam J
-
Posts
4,939 -
Joined
-
Last visited
-
Days Won
1
Content Type
Profiles
Forums
Gallery
Events
Blogs
Posts posted by Adam J
-
-
On 18/04/2024 at 18:29, FLO said:
Dont like this as an idea, You are basically paying for three things and need to upgrade all three things if at any point you just need to change one of them. Also I dont see a UAB3 type B connector at the back...and that makes me worry that you will be forced to use the ASI air with this camera.
Adam
-
16 hours ago, ollypenrice said:
Don't look at a stretched version of your flat to decide. It tells you very little. What you should do is read off the ADU value of the unstretched flat (ie the linear flat) in the corners and in the middle. I've found that it was perfectly possible to ask flats to correct a 25% drop-off in brightness between centre and corners, so you need to know what your light drop-off is. It may well be that your drop-off is greater than that but, before spending, it would be worth a check.
Is there any way in which you might get your filterwheel closer to the chip? You don't have any spacers between F/W and camera?
Olly
I would say that the main indicator that bad things are happening are the reflections and diffraction spikes most likely coming from the edge of the filter mount interrupting the light cone.
Adam
-
1
-
-
1 hour ago, Anne S said:
I had a similar problem when I installed a focal reducer on my 102mm Wave some years ago. A smaller ccd, just a SX694. Completely solved with 36mm filters. When I removed the reducer everything was fine. My ccd was only 16mm diagonal though. I'd like a 26M camera some day and I'm concerned that I'd need to go up to 2 inch filters. My 694 backfocus is 17.5 approx.
The reducer steepens the light cone which increases the risk of vignetting.
There is just no way that a even a F3 would need more than 1.25 inch filters with a SX694, I strongly suspect something else was going on. As I understand it 36mm is fine and used by many people on the 26M with no issues. The only thing I can think is that you must have had the filter a long long way from the sensor.
Adam
-
7 minutes ago, tico said:
Hello, Currently I use an ED80 refractor, with which I observe visually from my backyard, especially the Moon and doubles and planets, the rest of the objects due to light pollution I do not observe.... The truth is, I would like to upgrade to a larger telescope, without being huge, with more resolution than the ED80 for planets and the Moon. To notice a difference about the ED80, in your opinion what telescope could it be? I prefer it to be a telescope that is not too bulky or heavy, short, the mount I have is a celestron nexstar SE, I had thought about a 4" or 5" Mak...maybe? or a SC C5.. maybe a C6..? Although I don't like collimating telescopes... thank you so much TicoSkymax 150 would be my choice for planets. C6 would be ok but I think the skymax would be better.
Adam
-
So I had not noticed this before but it looks like Sony have put a OSC / Colour sensor based on the IMX492 design on their website.
Here:
IMX492LQJ_Flyer.pdf (sony-semicon.com)
not to be confused with:
IMX294CJK_Flyer.pdf (sony-semicon.com)
They are not the same sensor.
The IMX294CJK is currently used in the ASI294mc pro and it uses a odd Quad Bayer Matrix to provide 4.6um effective pixels but with each of the RGGB sub pixels themselves being made up of a cluster of 4....sub sub pixels...
Below this is the IMX492LLJ that is currently used in the ASI294mm pro mono camera, it can be used in 1x1 or 2x2 binning.
IMX492LLJ_Flyer.pdf (sony-semicon.com)
Note that ZWO assumed that the IMX492LLJ was in effect a mono version of the IMX294CKJ....it seems that as I predicted some time back this is not quite the case and the reason for the IMX492 designation was that the way the pixels are read is different and so a revision of the silicon has taken place.
SO this new IMX492LQJ is in fact a OSC version of the mono IMX492LLJ used in the ASI294mm pro that is using a conventional RGGB matrix on 2.3um pixels for a 12-bit, 47.08mp sensor.
I expect two things,
1) This is going to turn up in Astro cameras at some point in the future.
2) ZWO having painted themselves into a corner by calling the IMX492LLJ based camera the ASI294mm pro, have a headache now as to what to call a camera based on this sensor.....ASI492mc pro????
Adam
-
1
-
-
6 hours ago, AndrewRrrrrr said:
Evening All,
Looking for some advice:
I recently upgraded my camera from a 183M to a 26M. But using the same EFW with 1.25" inch filters. This is with a "wave 80" scope (80mm aperture, f6 with a 0.8x reducer so 384mm focal length)
Sensor to filter distance is 28.5mm.
I thought I might get away with it: according to the "CCD Filter Size" on astronomy.tools website which specifies a minimum filter size of 32mm (1.25" = 31.75mm)
Attached is the integrated LUM channel and it's corresponding flat. (I might re-do the flats to see if anything has changed, I'm still in the "shake down" phase of the new camera I guess......)
Or maybe it's something else altogether? I haven't attached the heater yet but it wasn't a cold or humid night
.
Opinions welcome, thanks in advance!
Yes the 1.25 inch filters will not cover a APS-C sized sensor, you will need 36mm filters for that. The best you can get from 1.25 inch is about F4 with a 4/3 sensor like the ASI1600mm pro or the ASI294mm pro. You can always just crop it to about that size for now without any negative effects but if you want to use the fill sensor you are going to have to change your filter and filter wheel.
Adam
-
3 minutes ago, Elp said:
Around 3.5-4A it was drawing. The absolute max based on when I measured each device separately would be 6A total.
In that case the voltage should not drop. Might be worth doing some more testing at lower current draw and see if it is still dropping,
How much charge did it take according to your charger?
Adam
-
18 minutes ago, Elp said:
I charged the battery up, went up to 13.4V. Tried it on my rig, the voltage quickly drops again to mid or just above 11V. Think it has to have a regulator connected up.
But for my purposes which is likely more power hungry than a "normal" setup I instead bought a Pegasus 12V 10A mains adaptor. Ran it for 30 minutes indoors with the peltiers running near 85pc and the rig didn't restart once, which is expected running off mains. So for me this is sufficient for my needs, I likely won't take this setup off site.
No that should not happen unless you are drawing more than 8 amps or so, as that will trigger some of the over current protection.
-
2 hours ago, Kyuss said:
I see your point!!! Seems to fit the case in the video.
yeah, take it as supporting up to APSC and you will be fine.
-
9 minutes ago, fireballxl5 said:
So you agree that it is (almost) a 100Wh capacity battery? Again, my understanding is that the power capacity is fixed with the time that current can be drawn determined by the voltage used (and the current level of course). This would mean that at 3.6V/1A the current rating is 27.65Ah, whereas at 12V/1A (using a handy USB PD 12V trigger) it would be 8.3Ah.
Regards, Andy
Yes but it does not mention 3.6volts at any point I can see, you basically have to reverse engineer that. For me at least that does not build confidence. The only voltage it mentions at the link is 28 volts for example.
-
13 hours ago, Elp said:
Of course not, here due to moisture in the air you need to use dew straps anyway so it's part of the process, allowing scopes to acclimatise is essential regardless of using dew straps or not. It could be manufacturing fault but statistically more glass and more likelihood of issues, so other triplets, quads, petzvals all could potentially suffer similar, the venerable SW Esprit, one of the best refractors for imaging suffers from it too.
On 02/04/2024 at 17:23, Kyuss said:Searching for a small refractor and that seemed to check all the boxes. Then Cuiv kinda ruined it with the pinched optics:
He is actually wrong it's not pinched, pinching will show that effect across the entire frame including the centre of the field. It's actually a sign that the corrector design is not working well at full frame.
It's a common effect in the corners of large sensors as the reducer effectiveness breaks down. I can't find a spot diagram for this scope. However for example this is a Askar scope.
Note the bottom right star 22mm spot shapes, when pixel sampled this ends up looking like a cross.
-
1
-
-
6 hours ago, fireballxl5 said:
Your calculation is implying that current and power capacity are the same. I'm no electrical engineer but my understanding is that the relationship between power and current capacity (Wh and Ah) depends on the voltage that is driving the current. So a stated power capacity of 99.54Wh (Anker product website for this power bank) implies a cell voltage of 3.6V, i.e. power / current 99.54Wh/27.65Ah = 3.6V. .
Happy to be corrected here🙂
yes I actually noted 3.6volts but in my post but for some reason it's been cut short.
-
33 minutes ago, fireballxl5 said:
Although my preference is for LiFePO4 batteries I've gone and bought one of these...
If falls just below the 100Wh limit and seems to be super slick. It will be used to provide primary power for my Canon DSLR and tracker mount at Monday's TSE, so weight, capacity and versatility were primary considerations here.
I'm now a fan of batteries that have PD capable USB outputs🙂
Andy
how are you getting 100Wh it's described as 27000mah so only 27Wh?
Adam
-
4 minutes ago, Elp said:
I've got the same brand charger so will charge it up, I did battery test with it though prior and it stated 100pc but I assume that's health or something.
So not sure on your battery monitor, make sure that the charger is set correctly as if its like mine it has many different options. My max charge voltage is about 14.3 - 14.4 volts on the LIFE charge profile.
Take note of how much you put into the battery.
Are you sure that monitor is for LIFE batteries and not Lead Acid as that would set 12.8 volts as 100% charge.
Adam
-
1
-
-
7 minutes ago, Elp said:
I tried this battery for a rig I'm putting together. The voltage started at 12.8V then dropped to below 11 within 5 minutes causing my airs to reset. Is this due to total power draw in amps/watts?
No if its starting at 12.8 volts it was not properly charged to start with. It sounds to me like it barely had any charge in it. It should start at 13.4volts when fully charged.
Are you charging it with a dedicated LIFE charger I hope?
Charging it with anything else is potentially extremely hazardous.
It should run a ASI Air for about 12-24hours.
Adam
-
1
-
-
On 11/02/2024 at 20:11, ollypenrice said:
At a first glance, the RASA 8 blows this out of the water. It has a 100mm longer FL but is nominally 3.6 times faster, though rather less given the central obstruction. Even so, it will cover the same FOV in far less time and, I think, with perceptibly better resolution. The RASA is not diffraction limited but it doesn't need to be when considering its competitor refractors of comparable focal length.
The RASA is entirely dew-proof without heaters, in my experience. Camera heat and fan deals with the problem.
Olly
Yeah it but the RASA is 2.9x the cost normally (although it is on sale), the RASA is hardly a portable scope and where this will sit just fine on something as cheap as a SA GTI the RASA is going to need a approx. 2k mount.
All said and done your are comparing a bulky £4.5k setup to a £1.4k grab and go / mobile imaging setup, making a comparison between apples and oranges.
Adam
-
2
-
-
On 26/09/2023 at 15:25, wavydavy said:
What do you consider the best filter for imaging narrowband mainly h-alpha, I currently am using a Baader 7nm 1.25"................is there anything better, make/quality etc. The camera is an ASI 553MM Pro.
Well that is a can of worms, you are opening.
Firstly the Baader 7nm is by no means a bad filter, it was the goto starter narrow band filter set for a long long time an for good reasons. On the Ha at least I never really found that you had much in the way of reflections.
So what are you going to gain? Well you will gain some signal to noise by going narrower potentially most so if you go with a 3nm filter.
However, you will also lose something in going for a 3nm filter and the thing you will loose is NII. What will that mean, well in my opinion it means less definition in quite a large number of targets and not just SNR. For this reason I tend to think that for Ha at least the optimal band pass is about 5nm and not 3nm.
I have never felt a need to upgrade from my 5nm Astrodon filters, for me they are perfect. For a 533m you can use 1.25, 31mm or 36mm filters. The first two will cover a IMX492 sized sensor in the future to about F4 / F3 respectively and the 36mm will cover a IMX571 sized APSC sensor. So think about your upgrade path, better not to have to buy twice.
The best filters are still made by Chroma and Astrodon, that is still what you yet if money is no object.
But if you are only using a small IMX533 base senor i am going to guess that money is a consideration.
Top tip: By the time you are spending more on your filters than you spent on your camera you are doing it wrong in my opinion.
1) Do you have a filter wheel?
2) Do you already have OIII and SII filters to go with the 7nm Ha?
3) What scope / scopes are you using? You may or may not need pre-shifted filters.
Adam
-
Its understood, but you really cant deviate from the method or it all goes wrong.
Adam
-
1
-
-
2 hours ago, Trippelforge said:
PixInsight
For every rejected frame it's "X" amount of data loss, that's what I am confused about. But perhaps I am not understanding things correctly. Say I take for example an hours worth of images at 5 minutes each, that's a total of 12 images (obviously). But if due to the longer exposures it caused me to lose say 4-5 images I just lost 1/3 of my data.
Because its not the whole frame that is rejected just the effected pixels.
-
3 hours ago, UKRoman said:
Just discovered that the ASI585MC Pro doesn't have a built-in dew heater. Doh, I should have read the specs properly. I already have the uncooled 585MC which I've tried for DSO imaging on a couple of occasions without success due to the sensor window dewing up. I may have to review plans before I unbox the new camera 🤔
All ZWO cooled cameras using sensors smaller than APSC don't use a dedicated dew heater but the are designed push waste heat from the thermo electric cooler into the camera housing preventing dew, you will not get dew unless the desiccant tablets need replacing. So in summery stop worrying it will be fine.
Adam
-
1
-
-
On 13/03/2024 at 00:50, Elp said:
I just tested it with a Celestron Lithium LT hence the need for the 12V female connectors. I'm only concerned with testing the 12V at the moment.
Within the monitor the connections are simply spring fit, you depress the corresponding connector "button", insert a spliced cable bare copper wire into the opened hole, release the "button" and the cable is retained. I don't think I need the shunt considering the amount of amps is low, but even if I did, I can't see how to connect the bridged positive and negative connections to the 12v female cables if I did need the shunt.
So if the battery is charged and you connected it correctly it should at least show voltage. If it's not showing voltage then it's probably just busted.
Adam
-
1
-
-
11 hours ago, pipnina said:
I thought I scored a real deal when I won the bid for a Canon 300mm f2.8 L (non is non usm) for only £600. Given the lens was originally over 4000 I felt pretty good about it.
Until I got my hands on it today. And learned that it WILL NOT manually focus and cannot be focused AT ALL unless a canon DSLR is attached to it. So it may as well be a brick as far as my astrocam is concerned!
I am beyond disappointed and to make matters worse, my normal DSLR is a Nikon so I can't even use it on that. I guess I can only hope that I can return the lens to the ebay seller and find another set of optics to try for compact and fast astro imaging unless anyone knows a way to hack it lol
One of these adaptors from Astromechanics would solve your problem.
You might be able to find one that is in someones old stock, I know FLO used to sell them. Apart from that it may be a problem importing.
Maybe a wanted notice in the forum and on Astrobuysell uk.
Adam
-
1
-
-
4 hours ago, Elp said:
Need some advice please. I may be able to do AP (well I think so anyway), but electronics was never my forte (even though I can build and usually fault find PCs), so putting together a custom rig which might need a new more powerful battery I decided to load test it first and bought this monitor and 2 off pig tail 12v 5.5 x 2.1mm female connectors (as my current battery is the same connection as is the asiair):
Now looking at the instructions I've wired it as per the top wiring diagram minus the external battery connections as ive only got the one battery but the monitor doesn't power on and also not the air. Any advice? I'm not sure if I can even use the 12v female cables I've got for this.
I would really need a better look at the connections. What type of battery are you using?
-
On 24/02/2024 at 14:26, tomato said:
I bid "Au Revoir" (hopefully) today to my damaged RC IMX 571 as it starts it's trip back to China. Eddie has said he thinks the repair will be "not much" so we'll see how that pans out. If I deem the repair quote to be uneconomic I'll ask him to keep it and put it in RC's Black Museum and I'll put the funds towards a new replacement. I suspect this will be from a UK based retailer though.
Given it's a current gen camera it would have to be over it's used price for it to be uneconomical. So that's probably anything upto and including £800 ish I would say. I really really doubt it will be that much.
Adam
RASA 8 on HEQ5 - Anyone do it?
in Discussions - Mounts
Posted
You may get away with it just about due to the relatively low image scale.
Adam