Adam J

It's a fast ish doublet so this is expected. As someone else above recommended I would grab a 2 inch Astronomik L-3 and place it in series with the LRGB filters.

As I understand it you have to use a Wide Photo AD 60 rotator in conbination with a standard t-ring to get the correct spacing. So the standart t-ring will give you 55mm back focus and then you need to add the width of that wide photo AD-60 rotator adaptor that screws into the m48 tring. The only referance I can find seems to show it to be about 8.5mm thick so that would give a back focus of 63.5mm from the end of the etention tube 66 (provided with the reducer / flattener kit and the sensor. Of course you could just purchase the rotator and then you can be sure that the back focus from its rear surface is 55mm. https://global.vixen.co.jp/en/product/3878_09/ https://www.ebay.co.uk/itm/Vixen-Direct-Wide-Photo-Adapter-Canon-EOS-3876-from-Japan/265043290476?_trkparms=aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D20131231084308%26meid%3D3b083878cf4f46099a1a5998b5e02fce%26pid%3D100010%26rk%3D2%26rkt%3D12%26sd%3D383115510547%26itm%3D265043290476%26pmt%3D0%26noa%3D1%26pg%3D2047675%26algv%3DDefaultOrganicWithAblationExplorer%26brand%3DVixen&_trksid=p2047675.c100010.m2109 I would confirm by chatting to your retailer though. Adam

Are you using a flattener or flattener reducer? If not then you may need additional extentions to account for the lack of flattener in the imaging train. Adam

I tried it and ended up having to sell the HEQ5 pro for a AZ EQ6 GT, so no i dont recommend it. The esprit 100 is a heavy scope for a 100mm aperture. With a OSC you will get away with it slightly more than I did with a mono camera as your effective image scale is reduced by the colour matrix but my stars where never quite round and I am picky, you may be less picky. I would say I was getting 1.1 arcseconds with the HEQ5 and that was not quite enough for my 1.5 arcsecond image scale ( Guide RMS should ideally be half the image scale). Adam

Esprit 100 is 550mm and a fantastic scope.

if anything the amp glow in the 294 is worse...its the 533 that has none at all.

Most of the time its just different lens cell designes causing the clear aperture to vary a little from scope to scope. It can be imperial to metric conversion. It can be to optomise the number of blanks you get out of a batch of glass. If a polilshing machine often leaves turned edges you will often make the lens elements slightly larger so that the turned edge can be hidden by the edge of the cell, perhapse more cost effective than buying a better machine and trying to get better polish right to the edge of the lens. I would not worry over think it. Adam

If i was going to get an OSC I would want it to be a large sensor like the 2600. However, I feel that there are other options appart from ZWO in this instance that are just as good. https://www.modernastronomy.com/shop/cameras/cooled-ccd/qhy-cooled-ccd-cameras/qhy268c-photo/ and cheaper, in some ways maybe better (camera rotator). I dont feel that the ZWO features such as USB hub and shorter backfocus are as relevant to OSC as you dont have a filter wheel. I say this as a happy ASI1600mm pro owner too. Adam

Is your 4 inch currently in orbit around mars?

In what perametre is it hundreds of times better than FPL-53? Otherwise that sounds like marketing nonesense. The problem is it can shatter along the crystal lattice, have seen it happen. It is harder to polish a crystal in comparison to an amorphous material. I am not saying it's not great stuff. Just it's not a miracle material either.

If your imaging galaxies then you don't need the FOV and the ASI533mc pro is a better sensor per unit area if that makes sense. Especially as the 294 has some issues with background calibration when going deep on galaxies. Smaller pixels with help with detail on the OSC for that use case too. Adam

It's brittle harder to polish and less inert (doesn't like water).

I would just use stellamate why anyone would want to lock themselves down to a single make is beyond me. You need to get all their stuff their camera filter wheel focuser guide camera. What if you don't like their filter wheel?

Its a good camera for sure I have seen many excerlent images taken with them. For me may of the advantages of ZWO are assocuated with their mono models and their accessories and backfocus. For an OSC those dont come into it and I would be happy to go with QHY in that case. Using the 200PDS your not going to get muc FOV are you galaxy imaging? For nebulas you are going to notice the smaller FOV in comparison to the DSLR. Adam

I would not think so, fluorite is not that much better than FPL53 and worse in some ways. More likely it would be on par with a FPL 51 triplet. Adam

The camera is more sensitive to blue and red than the human eye and hence in AP you will see CA that you cant see by looking through the scope. This being said the 115 F7 is a excerlent example of a well optomized FPL 51 design and I have seen many great AP images with it. Adam

I dont know that scope exactly but in my experiance anything that uses FPL-51 as a little bit of blue bloat. Not an amount that is unmanagable in imaging my any means and probably an not so apparent visually. I have a scope with one of the cheaper ED glasses in it and it is corrected through use of a mild Astronomik L-3 filter for AP use. Generally as aperture increases and F-ratio decreases colour correction is harder but its a non linear relationship and other factors are involved too. The lanthanum doped / coated element will act as a mild - violet filter and so should help in this regard. So the theory would be that a 6 inch FPL-51 triplet will not be perfectly corrected and but that CA will not be very in your face either. If no one has the scope perhapse that will give you something to think about. Adam

You would need one, maybe a small sensor like in the ATIK428 etc but not much bigger than that before you need one. Even something like a ASI183 would need one.

Build quality and consistency of the optics. There is just a lovely sold feel to their stuff. I own a Esprit and the optics are great but as most are. But I still feel like later in life I will want to upgrade the esprit as good as it is has a mass produced feel to it while the TSA feels premium. I would say that a 120mm is optimal for me in terms of weight to performance in a refractor...maybe 130 Burt certainly no more than that.

If I had that kind of money it would be the TSA-120 for sure. Adam

Depends on the price really and you have to consider the limited FOV of the sensor and lack of set point cooling. If we where discussing the mono version I would say you are correct but I think that in the case of the OSC there are some more modern DSLRs that will actually out perform it by quite a margin. Even some older ones will. But it all depends on the price. I personally would not pay more than £250 if I was buying one.

This is a record for a zombie thread. Moon did last visited the site over a decade ago so I don't like your chances of a reply. I would not be aspiring to own this camera in 2021.

When I was looking at this mount I found it difficult to find guiding examples that also gave detail on payload etc. In the end I got one and so decided to post some of my guiding here. Payload = 4kg Counter Weight = 2kg Nutral Balance. The grease was repleased with white lithium grease. I also shimmed the RA worm gear to give a better mesh as it was sitting a little low (added a thin washer under the mounting points at either end of the motor assembly). On a different point why the heck would anyone want to remove the spring loading and fix the worm??? Seems like a terrible idea to me so I just made sure the worm was free to move smoothly by adding grease to the pivot point and adjusting tention on the mounting screw, Connection via EQ Mod. No wind. Estimated 2 arcsecond seeing. Polar Alignment Via Sharpcap Pro graded as (Good). Some guiding examples. Guiding RMS was between 1.4 and 0.70 arcseconds over 50 samples during the night with the majority of guiding being between 1.0 and 1.2 arcseconds RMS. I strongly suspect that some examples of this mount are better out the factory than others. But with a little tweaking I think its reasonable to expact less than 1.5 arcseconds RMS so long as your within its load limit and well balanced. Mine was terrible out of the box, like really bad the RA axis was sticking badly. I guess I could have sent it back to FLO and have probably invalidated my warrently but to be honest my assessment was that after months of waiting for the mount I could well get a replacement that was either just as bad or worse. Hope this helps people thinking of getting one of these for mobile astrophotography. My conclution: Some tweeking required. Adam

Personally I recommend that unless your imaging at over 1000mm focal length that you dont bother with an OAG as it will be more trouble than its worth. Adam

I would try the Takahashi or baader one from FLO as opposed to the astro essentials. But before you do that test to see if it is the problem is it is the distortion pattern will change as you rotate the camera in the scope rings as it will follow gravity.