Adam J

Can anyone with one of these tell me if it has a crop mode? Its listed as having a max FPS of 20FPS in fill FOV and 14Bit. I am assuming that you can crop it and set it to 10Bit and it will but much much faster but this information does not seem to be avaliable. Was thinking of it as a solar / portable DSO camera when I dont want to take my wheel or dont want to remove my ASI1600MM Pro from the main scope etc. Adam

Of the cameras you list the 385 will likely serve you best. Really to get better you need to spend more and get something like the ASI533mc pro. Having said this though, if I was a betting man I would say its highly probably that ZWO will release an uncooled 533 at some point and with the low dark current and lack of amp glow that might be quite attractive. Adam

Contact Atik I would think? They purchased QSI.

Also if you dont like that argument then how about this one. OIII sits exactly in the dip in sensitivity between the Blue and Green Pixels and so you have around a 50% hit to sensitivity when collecting that wavelength with most OSC sensors. Dont get me wrong, I would still consider a OSC myself for a mobile rig so that I dont have to cart as much kit about and to make it lighter. But I would do that accepting the trade off is significantly less sensitivity. Adam

I know what you mean, but if you use it in super pixel mode you are taking a 50% resolution hit. The other problem is that I could use the mono 2x2 and in effect I am as the same resolution as the OSC but I have doubled my signal to noise ratio, which you did not do by using the OSC in super pixel mode. I can also play other games with that as I will be able to apply quite a bit of noise reduction before things start looking fuzzy but if I am already sampled at half the rate of the Mono when using OSC noise reduction will not be as effective. SO what I am saying is that if you are using the OSC in super pixel mode then the direct comparison is not to the mono in 1x1 bin its to the mono in 2x2 bin. If you are not using the OSC in super pixel mode then you have corse noise structure and end up having to apply more noise reduction than in the mono image and you end up back in the same place. In terms of colour bleed between pixels in OSC due to the less sharp cut off, that is why you will always struggle to get the more vivid differentiated core (yellow) and spiral arms (blue) in galaxy images. Now you can argue that the OSC might be closer to what we would see....but is that better from an artistic standpoint. Hope that helps. Adam

Cool looks like you are sorted then. Adam

No 5 bolts top and bottom of each ring they are imperial with a 2 inch spacing I think. You can get away with a vixen, if you are willing to put up with recentering after the flip. Also I would not mount a guide scope to the Esprit in that case as it will flex on the rings as the weight shifts. Normally vixen is fine on 100mm refractors from what I have seen but the Esprit 100 really is a lump. Adam

This sensor has smaller pixels and lower QE than the 294, as such not a great combination by comparison. The sensor seems to be close to the same size though. I would say that unless your main interest is galaxy imaging and you want the smaller pixels to deliver you with finer detail I would give it a miss. On the other hand it is true to say that the 294 has some calibration issues due to uneven cooling according to some of the owners over on cloudy nights. What I would say about the video is that she is associated / sponcered by Altair as it would seem that they send her lots of their stuff, so take it with a pinch of salt. I tend to only believe a review if I know the person paid for the kit themselves. Adam

I have a vixen on my Esprit 100 am replacing it with a larger losmandy. The Esprit is heavy and I found that it was shifting in the rings after a flip causing the target to require significant recentering. A the vixen was not preventing the two rings from twisting slightly in respect to one another. Adam

People always get this wrong and say it's 4/3 of an inch diagonal...which it can be in some cases but it's actually the aspect ratio.

You should have gotten the correct T2 spacers in with the camera.

I am just glad the OP is happy with the outcome. Adam

You dont want to go too short on focal length as your big sensor will allow you to maintain a large FOV without needing to sacrifice aperture and focal length. To give you the best advice i would want to know which full frame dslr we are talking about. In general though I think that anything with a reducer under your price range will be unlikely to cover a full frame sensor. So that leaves scopes that are fast enougth to enable them to get away with just a flattner. Kinda rules the ZS81 out to be honest and the Esprit 80 does not claim to cover full frame only APS-C. In all honesty unless you can push to a Esprit 100 or a FSQ85, which clearly you say you cant, then I think that you are stuck in the 70mm scope range due to price. So I would go with the WO ZS73 + FLAT73 as others have said and have some change left over. If you want to cover that full frame camera dont fall into the trap of the 0.8x reducer it will not cover that size of sensor, stick with the FLAT73a. Hope that helps. Adam

I doubt that he would find many technicians willing to work on a no fix no fee basis, so I think that was a harsh comment given that there is nothing to lose if he is not able to fix it. But as it happens I see that the technician in question has completed the fix and the board is in full working order in any case. Always nice to see a happy ending. Adam

Yes as you say chucking out a perfectly good MB for the sake of a couple of components is part of whats wrong with the world these day. Glad you got it fixed and i will be using this chap in the future if I have problems.

I am going to guess that heat sink will be too small but it really depends on how many watts that peltier is. A water block is a better bet, unless your going to enginear it like tomato above. Too heavy is a problem too as it will cause tilt...its a small sensor mind you.

I think the issue with CCD calculator is it was written prior to the CMOS age. The smallest pixel CCD was around 4.5u when it was made and so it was virtually impossible to oversample with a small refractor. Hence there is no catch to tell you that you are trying to image at a smaller scale than the Daws limit of your scope. Smaller aperture refractors <80mm have also become much more popular. It could use revising.

Sampling is not just about what the stars look like it's about resolvable detail and photon pixel flux. Unfortunately that calculator is only considering star roundness as related to seeing within its calculation if it's the tool I think it is. The stars in your images will look fine, not bloated or blocky as both cameras are in that optimal range of 1-2 arcseconds per pixel. But that's only part of the picture. It's about how much detail / resolution you expect to attain in the DSO you are imaging itself. That is limited by more than just your image scale, it's limited by guiding, seeing, Daws limit and signal to noise in the image. A good debayering algorithm will get most of the resolution lost by the RGB matrix back. So you certainly don't end up at 50% image scale in the red / blue. But in the end a 70mm scope does not grab that many photons so you can't just keep spreading them over increasingly smaller pixels and expect to attain sufficient signal to allow you to extract additional detail. In the end what I am saying is this. If you take your 72mm scope at about 400mm focal length and 1.1arcsecond image scale and put that up against my 100mm scope with 550mm focal length and 1.4arcsecond image scale. Which do you think will image a target like m81 in more detail and achieve a better image. I believe strongly it would be my scope and so at that point I would say your oversampled and you would be better off moving to larger pixels for an increased SNR as clearly the smaller pixels are not helping you. Adam

It really is just seeing. Some nights I get 0.5 on my AZEQ6 GT and other nights I get 1.2 on the very worse nights even higher. Its one of the reasons people say that going to less than 1 arcsecond per pixel in the UK is not worth it most of the time. The trick is to not be tempted to keep making changes as all you are doing is chasing the seeing and you might even end up making things worse. If you have some settings that worked well once then stick with them and have faith that its probably seeing. Adam

The interesting thing being that it can only be displayed as if it was square once its on a computer monitor. Incidently I see your image next to mine in the astrobin top pics. Nice.

8.2 x 8.4.....its less rectangular than it is just not perfectly square only 2.4% differnece, but ok.

That must be the V1 then because looking at the v2 those are square.

I dont know of any camera with non square pixels. So if you find one let me know :)

Rob, Take a look at my post in this thread. The answer is mono is still a long way ahead of OSC. Adam

Sorry but thats just not the case, the Daws limit (the limit of resolution due to aperture) for a 72mm scope is 1.61 arcseconds per pixel if the optics are good. The ASI533 will give 1.84 arc seconds per pixel which is a very good match to the SW72ED. On the other hand the ASI183MC Pro will sample at 1.18 arcseconds per pixel, this means that its samping at a significantly higher rate than the Daws limit of a 72mm scope and will never acheive that resolution in practice. As such the ASI183MC Pro is over sampled. This will mean less sensitivity for no gain in resolution over the ASI533MC Pro. I would not recommend the ASI183MC Pro for this reason and would 100% say that the ASI533MC Pro is a better choice for the refractor. The only way to overcome this oversampling would be to bin the data 2x2 at which point you would be undersampled. Adam