| is the above a good combination? | |
|---|---|
| yes | |
| no | |
| maybe ;) | |
| Login to vote and view results. |
3.81
#...
·
 |
|---|
|
hey guys, title says it all. searching for any opinions on this combination. if possible unprocessed single frame fits or raw files would be great. cs and thanks Andi |
6.15
#...
·
·
1
like
|
|---|
|
I don't see a selection for maybe... ;-) Full Frame sensor cameras can be very demanding, but the Esprit line has a very good reputation for edge to edge image quality. I love my Esprit 100 although I do pine at times for the 150 or possibly a Stellarvue SVX152 for certain targets. I say maybe because the limitation is the image circle size, IMO. The Esprit 120 with the FF has an image circle of 44mm which should pose no issues with the a full frame camera. The 'complication' is that focal reducers also reduce the image circle size. How much is the question. According the Skywatcher, their .77x focal reducer reduces the image circle from 44mm to 34mm. This indicates there will be some vignetting at the corners. Good calibration frames should offset that in your stacking software. So my answer is yes, well maybe. |
|
3.81
#...
·
·
2
likes
|
|---|
I don't see a selection for maybe... ;-) Hey Clayton, as usual thank you very much for sharing your wisdom with me ;) you are right with everything you say. Skywatcher itself says the image circle is 34mm but it will work up to full frame. there are a few great shots on astrobin that pair the reducer with a full frame camera but all these are already processed. The only single unprocessed file i have seen of this combination had stars, that reached a good way into the image, that i would just not be happy with. As i don’t know anything else about the above mentioned frame i would hope that some owners of this combination could share some information with me. cs Andi |
7.58
#...
·
·
2
likes
|
|---|
 I just put together one such system for a client, ZWO2400MC with Esprit 120 and 0.77x reducer. No tip tilt adjustment here, and I would say this is pretty dang good. |
|
3.81
#...
·
|
|---|
Bray Falls: Thank you Bray! That is exactly what i was looking for. do you think that the smaller pixels of imx455 sensor would produce equally acceptable results? |
|
6.15
#...
·
·
1
like
|
|---|
Andi: I think the more critical factor (with the Esprit 120) is the focuser, and with full frame camera - sensor tilt. If the 120 is like my Esprit 100, the draw tube of the OEM focuser is out about 2/3rd of its total extension to reach focus with the field flattener/flattener-focal reducer. It is not a bad focuser and the for the prevalent imaging setups/cameras at the time of its design is a good (ish) focuser. However, the new modern ASP-C and full frame sensor cameras are larger and significantly heavier that the sensors of the older 4/3 frame size like in the ASI294MC that I started with. Couple that with larger sensors that utilize almost entire image circle and tilt (and focuser droop) can become apparent. When I switched from my ASI294MC to an AS2600MM, I suspected I might be seeing some sensor tilt, but as I watched more closely I could tell there was a slight shift as the telescope tracked - noticeable when Blinking large (long duration/lot of frames) images sets in Pixinsight. I chased this and did discover there was very slight 'play' in the draw tube. It wasn't enough to notice with the lighter/smaller sensor camera, but started to become noticeable with the heavier camera. When I exchanged the filter slide for an EFW, there wasn't much doubt anymore. I replaced the OME focus tube/focuser with a Moonlite Express Nightcrawler. Much more robust (much heavier as well) and it eliminated the isue of draw tube droop and increased the focuser tube instrument weight capacity to approximately 26 lbs. However, when I went from a guide scope to an OAG-L, I found that the ZWO tilt plate which was OK in the non-OAG position on the Camera Body, exhibited some slight amount of 'flex' when mounted on the OAG-L as required. The N.I.N.A. 3rd party plugp-in, HocuFocus, has a really good/easy to understand tilt/backspace tool called Aberration Inspector. I'm not going to go further into that tool but you can find a great tutorial on it by Patriot Astro in YouTube (linked below). The portion on the Abarration Inspector begins at 26:40. https://youtu.be/M1-izvBlO44?si=_j3_ZuN6fRobvPRO The tool works great, but it demonstrated the flex of the ZWO tilt plate when it has the entire rest of the imaging train hanging off of it(OAG-L, EFW 2"x7, ASI2600MM). Plus trying to adjust the tilt the ZWO's three adjustments screws to a four corner tilt data/illustration is, well, tedious. There is an alternative to the 'flex' ing ZWO tilt plate and it moves all of that back to the Camera. That is the ASG Photon cage. It is a very robust and rigid tilt and back focus adjustment device that literally 'contains' the entire camera. It was designed to work with the output provided by the HF Aberration Inspector. There are a series of videos that introduce the device, its installation, and use with the N.I.N.A. HF Aberration Inspector. The first one is linked below. Besides being a very easy way to manage tilt and backspace, there is a pretty good discussion of both issues within the video. I did get a Photon Cage and wouldn't do without it now, but you don't need the device to learn a lot of useful things from the videos. One of the other things you may need at some point are some custom adapters / spacers. Since ASG owner told be about Precision Parts, they've been my goto for anything specific to my setup that I needed. (also linked below). https://youtu.be/RJr7OiD5Xeo?si=1tAPd6DxXAhlY18X PreciseParts Build-An-Adapter |
4.06
#...
·
·
2
likes
|
|---|
|
Hi, I tried ASI6200MM with my Esprit 150 with 0.77x reducer and had to work on my backfocus to get acceptable results. It was one of the reasons for me to downgrade to 2600MM. And as expected, worked fantastic with APS-C. hope it helps. |
|
6.15
#...
·
·
1
like
|
|---|
Bray Falls: Bray, Thanks for the image; the 2400 is a camera that intrigues me (more than the 6200 frankly) but I've won't consider it as an OSC camera, so I keep hoping for a 2400MM at some point. VisibleDark posted some images of a test with the Starizona APEX-L FR for the Esprit 100 a couple of years back, using a 2600mm. The image circle with the FR is 30mm according to Starizona specs which just slightly larger than the APS-C diagonal in the ZWO 2600 of 28.3mm. His images still had vignetting in the corners, but a good set of flats took care of it in the final calibrated masters. I do notice in the two lower corners of your images, and to a lesser extent in the upper left, some indications of either tilt and/or backspace issues. The elongation of the stars seems to point primarily toward the center of the frame which is usually back space. A run on the Aberration Inspector might show how much is back space and how much is sensor tilt. Just my experience with the HF AI and the Photon Cage; by the time I complete eliminating/minimizing the tilt I've found that my backspace has settled within tolerance. Just luck I suppose, but since the setup starting point puts the BF in the Photon cage at 2mm out to provide room for tilt adjustment it's not too surprising to find that tilt adjustment also affects the back space. Just guessing, I don't want to read too much into a posted image rather than the original frames. CS Clayton |
2.71
#...
·
·
3
likes
|
|---|
|
I find that the problem is different people have different tolerance levels for misshapen stars, and manufacturers claim “full frame” that’s corrected with flats and don’t claim pinpoint to full frame. I’ve even seen people post images with obvious CA and + shaped or comet shaped stars and comment on the post that the scope is “stunning” and “pinpoint”. It’s sad that one can’t look at some form of industry standard to judge quality in this day and age. |
2.11
#...
·
·
1
like
|
|---|
|
I use a Esprit 120 ED with the x0.77 reducer on a Nikon Z7 full frame camera. The edges are darkened but the flats correct well and the full frame is usable. Here are some photos taken with this combination: https://lucnix.be/_data/i/upload/2023/09/10/20230910102911-b230fb0f-xl.jpg https://lucnix.be/_data/i/upload/2023/09/16/20230916111154-63a7e7c7-xl.jpg https://lucnix.be/_data/i/upload/2023/09/09/20230909170220-853f81c7-xl.jpg https://lucnix.be/i.php?/upload/2023/09/16/20230916134709-0e414718-xl.jpg Also visible in my Astrobin gallery. |
6.06
#...
·
·
2
likes
|
|---|
Sean Mc: Also if their seeing is bad their stars are going to look more acceptable. Everything looks ok when its bloated. I frequently get down to 1.4-1.8" seeing and almost everything people call acceptable is not to me. |
2.11
#...
·
·
2
likes
|
|---|
Andi: *** Type your reply here * not m42,not m48 , i Hight recommend m54 or above in all optical train my zwo 6200mm pro working with out any aberration with WO FLT 120 , GT 81 WIFD, REDCAT51 with M54 , however recommend take some action with the TILT |
