106 replies to this topic

[Whereisclearsky]

I haven't used my Sony cameras directly on a scope so that is not something I knew of.

 

Sony also arguably has the best selection of lenses suitable for nightscaping. The Loxia 21 2.8, GM 24 1.4 and quite a few others.

 

Canon has fewer options.

 

Greg.

Sony has concentring rings too as a bonus, the rings of power.

Edited by Whereisclearsky, 17 January 2024 - 07:45 PM.

[Digitaliz.se]

Don't worry too much about it. This is A7R4 with Sigma 85/1.8 DG DN at f/1.8 and there are no rings. Stacked, Background extraction and Auto Stretch in PixInsight.

I call the lenses, the Power of light gathering.

/Stefan

 

 

Sony has concentring rings too as a bonus, the rings of power.

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Edited by Digitaliz.se, 18 January 2024 - 04:47 AM.

[Digitaliz.se]

Star form at 300%

 

/Stefan

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[Digitaliz.se]

After Blurexterminator and star calibration at 300%

 

/Stefan

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Edited by Digitaliz.se, 18 January 2024 - 05:07 AM.

[Whereisclearsky]

Not sure if you mean your camera doesn't "do rings" by posting the screenshot?

If yes then I didn't mean that every Sony camera struggles with it.

 

My A6400 certainly did.

[erictheastrojunkie]

Not sure if you mean your camera doesn't "do rings" by posting the screenshot?

If yes then I didn't mean that every Sony camera struggles with it.

 

My A6400 certainly did.

Stefan has made it quite clear that he hasn't had any problems with his Sony cameras through these various threads (or that the problems dont interfere with his astrophotography pursuits), but people need to understand that they do exist and they do impact a lot of cameras and that there is a very good chance you will see it impact your image quality if you have higher standards.

[photobookie]

I like your analyses.  Indeed both have their pros and cons.  What you mentioned are also my concerns if one day I am to choose the two.

 

Let me throw in another point: the small lens mount of Sony.  The E mount was originally developed for APS-C cameras (NEX). Later Sony put a full-frame sensor behind the mount.  I guess Sony was not serious about this product and did not expect it to be such a big hit.  Anyway, the result is that if you put the camera behind a telescope with large focal ratio (>5), you will see severe vignetting in the corners.  It can be so severe that even flat-field correction does not really work in the extreme corners.  So if you plan to use a Sony E-mount FF camera on a telescope, you need to factor this in.  It's not a problem on lenses, as the light path from lenses is completely different.

If I'm using an FSQ 106 at its native f5, will a Sony A7RV be useable or will severe vignetting occur?

[whwang]

My gut feeling tells me that it should be useable. I can’t guarantee though.

[dsm1212]

I have and a7r5 and I happen to have been collecting gear to take a first try at some astrophotography as soon as weather permits. I plan on going through and disabling everything which might modify the raw output (dynamic range, awb, etc), but I was going to use lossless compressed. That should be ok with respect to star eater, no?

 

So far I picked up:

- a 50mm guide scope and mono camera

- sky watcher gti mount

- vixen bar and brackets to mount everything

- pocket pc with windows 11, nina and related software

- bogen tripod dedicated to this. older but it's pretty heavy so probably ok

- usb power brick and cables

 

No filter yet, I'm in a bortle 4-5 area. I've got a sony 100-400mm lens with a 1.4x converter so I can get to 540mm right now. I'm waiting for the guide cam to arrive, but everything seems to work in house so far.

 

Any other things I need to start that don't break the bank? I'm thinking of making a little panel for the pc and power brink out of a cutting board that I can attach near top of the tripod.

 

steve

Edited by dsm1212, 13 February 2024 - 07:37 PM.

[xonefs]

I picked up a Sony A7C R. It's $1000+ cheaper and for astro purposes shouldn't be missing too much of anything from the RV. Main compromises are the EVF, framerate and buffer which don't really matter for timelapse and tracked shooting. 

 

Due to release date I am sure star eater is gone as well but I can do some tests for Mark to confirm it. 

[Digitaliz.se]

Too bad you already picked it up, but I would rather recommend getting an older R-version and modd it.  Either way, don't worry too much of the star eating phenomenon. I  don´t.

 

/Stefan

 

I picked up a Sony A7C R. It's $1000+ cheaper and for astro purposes shouldn't be missing too much of anything from the RV. Main compromises are the EVF, framerate and buffer which don't really matter for timelapse and tracked shooting. 

 

Due to release date I am sure star eater is gone as well but I can do some tests for Mark to confirm it. 

Edited by Digitaliz.se, 29 February 2024 - 02:56 AM.

[Catchlight]

Very interesting thread! I am new to DSO astrophotography and have been using the A7RIII and never noticed the star-eater problem, probably because I didn't know where to look. I usually shoot with non-Sony lenses, and if I understand correctly that seems to avoid the problem. When I looked at images taken with the Sony 20/1.8 and 14/1.8 they do seem to suffer from star-eater, but since I usually use those lenses for timelapse, it doesn't make much difference.
To illustrate the result with non-Sony lenses I am sharing a few of those images of M42:

single full-frame image of M42:

 

 

Same image at 100% crop

 

 

Final image (only 35 minutes integration and very much a beginner at Pixinsight)

 

 

 

Edited by Catchlight, 29 February 2024 - 03:52 AM.

[sharkmelley]

I picked up a Sony A7C R. It's $1000+ cheaper and for astro purposes shouldn't be missing too much of anything from the RV. Main compromises are the EVF, framerate and buffer which don't really matter for timelapse and tracked shooting. 

 

Due to release date I am sure star eater is gone as well but I can do some tests for Mark to confirm it. 

Yes, I'd love to look at a raw ISO 1600 room-temperature long-exposure dark.  A 5min exposure is preferable but 30sec will do.

 

If you're using it with a Sony lens then we could also test if the concentric polygon problem has gone.  That requires a set of ISO 100 flats, described by my test protocol.

 

Mark

[RichA]

So it is the lens after all that causes the camera to missbehave. Just use a telescope, or an lens that has no electronic connections, or a lens that is not supported by the camera. 

 

"Conclusion

For lenses recognised by the camera firmware, the Sony lens corrections are still applied to the raw image data even when lens corrections are disabled in the camera menu. This is potentially a big problem for deep-sky astrophotograpy, causing concentric coloured poygons to appear in the background. The good news is that the lens corrections are not applied for (non-electronic) legacy lenses nor for directly-attached telescopes."

Some lenses now are such optical junk that they can't function at all without specific cameras.  Sony is prominent here.  The upside for conventional photography is the (kind of) elimination of distortion and chromatic aberration in images.  One of the hallmarks of the mirrorless camera (brought out originally by Panasonic in 2007) is the ability to use just about any other lens, with adapters all the way back to the beginning of lens production.  Much of the current crop of lenses will essentially be doorstops if and when the electronics on existing cameras fail and future cameras don't support them.

[Digitaliz.se]

Shall I read this that you think Sony is prominent in making lenses that are optically junk?

Edited by Digitaliz.se, 01 March 2024 - 05:43 AM.

[erictheastrojunkie]

Some lenses now are such optical junk that they can't function at all without specific cameras.  Sony is prominent here.  The upside for conventional photography is the (kind of) elimination of distortion and chromatic aberration in images.  One of the hallmarks of the mirrorless camera (brought out originally by Panasonic in 2007) is the ability to use just about any other lens, with adapters all the way back to the beginning of lens production.  Much of the current crop of lenses will essentially be doorstops if and when the electronics on existing cameras fail and future cameras don't support them.

I'm guessing you are talking about the focus by wire systems in modern lenses which require electrical control by the camera, sometimes even manufacturer specific camera type. I do agree that this system is archaic and an abomination for photography/cameras in general, as someone who loves to adapt lenses to various cameras (even cooled astro cameras), not even being able to adjust aperture or focus with a lens attached to a camera without electrical control is ridiculous. But in terms of optical quality, sharpness, correction of various aberrations, etc, modern lenses are so far above and beyond anything from 10-20+ years ago it's not even worth discussing that idea. That's not to say there are no junk lenses being made a sold these days, but virtually every manufacturer is releasing lenses now that are far superior to equivalent (in terms of focal length/range) lenses from the past. And they are doing it with faster apertures, sometimes even with smaller/lighter bodies. The only manufacturer of lenses that leaves me scratching my head in terms of "why can't they figure it out" is Canon, especially for astrophotography. For whatever reason Canon just sucks at designing and making lenses that are fast, sharp, and free of aberrations. But Voigtlander, Sony, Sigma, and Nikon are crushing it, putting out lenses that are VASTLY superior. Voigtlanders APO lenses especially are benchmarks for modern design, they are small, lightweight, fully manual, the sharpest you can get, and pretty much free of all aberrations wide open. 

[xonefs]

The voigtlanders are nice but still just a bit slow and the small size means they vignette considerably wide open. When they only start at f2 and the corners wide open are several stops darker than the center and then lens needs to be stopped down to even it out, it is still not ideal.  I would rather see them be made bigger/faster. 

 

The 50mm voigtlander apo vignettes -2.6 EV in the corners of full frame. The 35mm APO is -3 EV darker in corners. That's not good... I had them both and didn't keep them. 

Edited by xonefs, 01 March 2024 - 11:36 AM.

[erictheastrojunkie]

The voigtlanders are nice but still just a bit slow and the small size means they vignette considerably wide open. When they only start at f2 and the corners wide open are several stops darker than the center and then lens needs to be stopped down to even it out, it is still not ideal.  I would rather see them be made bigger/faster. 

 

The 50mm voigtlander apo vignettes -2.6 EV in the corners of full frame. The 35mm APO is -3 EV darker in corners. That's not good... I had them both and didn't keep them. 

Here's the problem though, and believe me I've tested probably WAY more lenses than most people here (for astro I've used around 75 lenses now), most fast lenses (faster than f2) have to be stopped down anyways to correct aberrations, improve edge sharpness, and reduce vignetting. The VAST, VVVASSSSTTTT majority of fast lenses that are f1.4 or faster produce unacceptable images at f1.4 or even f1.8, most produce reasonably acceptable images at f2, f2.5. For high quality astro imaging most lenses have to be shot at f2.8 or more stopped down anyways. The Voigtlanders do have extreme vignetting, but even stopping them to f2.2 really reduces that substantially, and something else the Voigtlanders have started implementing is a round aperture at f2.8, so you can get perfectly round stars at f2.8 without having to use an aperture mask. I'd rather have a lens like the Voigtlander which is small, lightweight, free of any focus-by-wire nonsense, and incredibly sharp/free of aberrations at f2 than a big, heavy, focus-by-wire lens that is f1.4, but has to be stopped down to f2-f2.8 to be really good. When you do high resolution tracked nightscape imaging like I do then you find that the process becomes much easier when you have a lightweight payload that is easy to balance, not having to use big/heavy lenses that become annoying for weight balancing makes life a lot easier. 

 

I've used/tested pretty much all the new Sony's, Nikon's, and Sigma lenses, the Voigtlanders (especially the 35mm APO and 50mm APO) are still the best at those focal ranges for the metrics that matter for astrophotography. This year I'll be using the Sigma Contemporary offerings, 35mm f2 DG DN and 65mm f2 DG DN, with my Sigma Fp for Milky Way imaging. I used the 24mm Contemporary a couple times last year and was pretty impressed with it, but my main focal lengths are 35mm and 65mm for nightscape imaging these days. 

[xonefs]

sure, I suppose the weight thing is valid. the sigma 40 is certainly taxing on star trackers and ball/pano heads. Generally the bigger sigma and sony f1.2 and f1.4 lenses are pretty good stopped down to f2, and the vignetting performance is much better than any of the native f2 lenses even when they are stopped down to f2.8. Most of those lenses really need to be stopped down to f4+ for decent vignette performance, and I feel this is the most underrated lens stat for astro, especially when you are stitching panorama. Flats don't make up for the loss of light. 

Edited by xonefs, 01 March 2024 - 12:08 PM.

[erictheastrojunkie]

sure, I suppose the weight thing is valid. the sigma 40 is certainly taxing on star trackers and ball/pano heads. Generally the bigger sigma and sony f1.4 lenses are pretty good stopped down to f2, and the vignetting performance is much better than any of the native f2 lenses even when they are stopped down to f2.8. Most of those lenses really need to be stopped down to f4+ for decent vignette performance, and I feel this is the most underrated lens stat for astro, especially when you are stitching panorama. Flats don't make up for the loss of light. 

I don't even know how many nightscape panoramas I've done over the years, hundreds, with everything from 14mm lenses up to 135mm. No amount of vignetting has hindered me from post processing them except once when the wildfire smoke was so bad here I couldn't get a flat field from one frame to the next, still managed to get a decent pano out of it with the Nikon Z7 and 85mmS lens:

 

 

If you look at the fell res image and zoom in you can see the stitching artifacts caused by the heavy vignetting from the smoke, but at normal res and screen viewing it's harder to see. 

 

Virtually all of my panoramas are 10-50 frames (never stacking), I've done up to ~80, so I'm well versed in the post processing needs it takes to get a nice stitch across the whole field, including vignetting correction. RAW conversion and Stitching software has made it very easy to correct uneven illumination/vignetting across the frames, I don't even really consider vignetting when weighing lens quality because it's so easy for me to fix in post and I almost never use flats/calibration for my nightscape imaging. I won't consider a lens that has to be stopped down past f2.8 and with the bevy of quality lenses out there that can be shot from f2-f2.5 there's really no reason to consider a lens that has to be shot at f2.8 either. Throw in the post processing options that exist now (things like BlurX and NoiseX in PixInsight that can even be applied to nightscape imaging) and really the lens options available to people are huge these days. If you are having to use a lens at f2.8 or more stopped down for nightscape/Milky Way imaging then the lens is not good. The Art 40mm is still my benchmark in terms of image quality, but it's physical size makes it a non-starter for me these days. Even the Art 40mm has pretty bag vignetting, I shot mine at f1.8 to fix some of that. 

[nhmorgan79]

Here's the problem though, and believe me I've tested probably WAY more lenses than most people here (for astro I've used around 75 lenses now), most fast lenses (faster than f2) have to be stopped down anyways to correct aberrations, improve edge sharpness, and reduce vignetting. The VAST, VVVASSSSTTTT majority of fast lenses that are f1.4 or faster produce unacceptable images at f1.4 or even f1.8, most produce reasonably acceptable images at f2, f2.5. For high quality astro imaging most lenses have to be shot at f2.8 or more stopped down anyways. The Voigtlanders do have extreme vignetting, but even stopping them to f2.2 really reduces that substantially, and something else the Voigtlanders have started implementing is a round aperture at f2.8, so you can get perfectly round stars at f2.8 without having to use an aperture mask. I'd rather have a lens like the Voigtlander which is small, lightweight, free of any focus-by-wire nonsense, and incredibly sharp/free of aberrations at f2 than a big, heavy, focus-by-wire lens that is f1.4, but has to be stopped down to f2-f2.8 to be really good. When you do high resolution tracked nightscape imaging like I do then you find that the process becomes much easier when you have a lightweight payload that is easy to balance, not having to use big/heavy lenses that become annoying for weight balancing makes life a lot easier. 

 

I've used/tested pretty much all the new Sony's, Nikon's, and Sigma lenses, the Voigtlanders (especially the 35mm APO and 50mm APO) are still the best at those focal ranges for the metrics that matter for astrophotography. This year I'll be using the Sigma Contemporary offerings, 35mm f2 DG DN and 65mm f2 DG DN, with my Sigma Fp for Milky Way imaging. I used the 24mm Contemporary a couple times last year and was pretty impressed with it, but my main focal lengths are 35mm and 65mm for nightscape imaging these days. 

The Voigtlander 50mm is a really good lens in a small package, but my final verdict when I had to sell one, even taking AF out of the equation, was the keep the nikon 50mm 1.8s. Both lenses need to be stopped down to 2.8, but the Voigt had more noticeable vignette at that aperture and wasn't quite as sharp at the edges as the nikon, but it was really close. That said, I've also owned a copy of the 50mm 1.8s that wasn't great. Nikon does seem to have some QC issues that show up in astrophotography. I didn't like the 35mm apo for astro (it was a beautiful lens for regular photography); maybe it was just my copy but there corners weren't good. The nikon 35mm 1.8s that I owned was a better lens, but did suffer from some purple fringing that the Voigt didn't, but the sony GM 35mm 1.4 also has strong purple fringing (although not as bad as the 24mm GM). My experience with the 40mm art has been hit or miss. I owned one for L-mount when I had an FP that was stunningly good. The two copies I've had for nikon didn't seem to like the FTZ adapter. I don't know if the backfocus is a touch off with the adapter or if there is just high copy variation, but both nikon versions showed much more coma in the corners. Maybe the best 50mm I've used is the Sony GM 1.2. It was usable at f2 and lighter than the sigma art.

[erictheastrojunkie]

The Voigtlander 50mm is a really good lens in a small package, but my final verdict when I had to sell one, even taking AF out of the equation, was the keep the nikon 50mm 1.8s. Both lenses need to be stopped down to 2.8, but the Voigt had more noticeable vignette at that aperture and wasn't quite as sharp at the edges as the nikon, but it was really close. That said, I've also owned a copy of the 50mm 1.8s that wasn't great. Nikon does seem to have some QC issues that show up in astrophotography. I didn't like the 35mm apo for astro (it was a beautiful lens for regular photography); maybe it was just my copy but there corners weren't good. The nikon 35mm 1.8s that I owned was a better lens, but did suffer from some purple fringing that the Voigt didn't, but the sony GM 35mm 1.4 also has strong purple fringing (although not as bad as the 24mm GM). My experience with the 40mm art has been hit or miss. I owned one for L-mount when I had an FP that was stunningly good. The two copies I've had for nikon didn't seem to like the FTZ adapter. I don't know if the backfocus is a touch off with the adapter or if there is just high copy variation, but both nikon versions showed much more coma in the corners. Maybe the best 50mm I've used is the Sony GM 1.2. It was usable at f2 and lighter than the sigma art.

Definitely QC problems existing from manufacturers these days, my copy of the Nikon 50mmS was so bad it should have never left the factory and unfortunately the weather was so bad I didn't get to test it until after the return window, luckily I was able to sell it to someone who didn't have the strict quality needs like astrophotography demands. I did everything I could to talk my wife out of getting the 50mmS for her Z7, she did anyways, and her copy was exceptional which mystified me. My Voigt 50mm APO was outstanding as was my 110mm APO, my wife's Voigt 65mm APO is really good, but not as good as the first 65mm APO I had a few years back. The 35mm APO I rented and tested for a little while was exceptional as well, compared to the 35mmS I had....no brainer, the 35mmS was awful and well down the list of 35mm lenses I'd consider usable for astro. I think the 35mm realm has the most options, the Tamron 35mm and Voigtlander 35mm APO are the two best, better than the Sony 35mmm GM, better than any Canon 35mm, better than the Sigma 35mm's although I haven't done testing of the 35mm DG DN f2 which will be my wide lens this year. Of course at that focal length you're going to compare to the Art 40mm, which is still the overall king of image quality IMO, but there have even been reports of copy to copy variation with that lens as well so YMMV. I've been fortunate enough to be able to test and use a lot of lenses for astro, some with multiple copies of a single lens, and I've been doing it for quite a while now so I have a pretty good grasp on the various levels of lens quality out there. I've even gone as far as 3D printing my own adapters to test lenses on different cameras, including cooled astro cameras, as well as modifying lenses with shims/tilt mechanisms to sort out issues in terms of back focus and tilt. 

 

One thing is absolutely certain, I always recommend buying a lens from a place with a return/exchange policy these days. The optics are what matter the most (not taking into account the mount, of course) for producing the best image quality and I don't think there is a guarantee that any lens you buy will be 100% perfect even if it does have a lot of testing reports by many users. When I bought my 50mmS at the time virtually every test report from many users remarked at how exceptional it was, the best 50mm that wasn't a Leica sort of thing, and when I finally tested mine it was laughable at how poor it was. If you use enough lenses you are going to encounter lemons eventually while everyone else is singing their praise. And as for vignetting, I'll just reiterate what I said to Xonefs, it's really not that big of an issue once you dial in your post processing methods and use the readily available options for correcting it in post. 

[xonefs]

And what is your go to for vignetting correction/sitching?

 

 

For sky panos I've worked stitching in APP and or pixinsight where panel overlap is integrated and not just chopped off like traditional pano stitching software like ptgui. This is a lot less forgiving and does require decent calibration/flats. If using ptgui or similar the edges get cropped and it is less of an issue and easier to correct in software, but then all lens corner performance is less of an issue if you are doing this. 

Edited by xonefs, 01 March 2024 - 01:11 PM.

[erictheastrojunkie]

For my nightscape imaging I do almost no editing in APP/PI, I open the RAW files in ARC and do frame by frame distortion, vignetting, and midpoint corrections first, then do a quick export as JPG's and quick stitch in PTGui with the full correction parameters ran on auto. I look at the stitched pano and make extreme curves adjustments to it and see if I can find stitching artifacts, then go back to the ARC and make further adjustments as needed. I get the frames as even and distortion free as I possibly can in ARC before stitching with PTGui Pro that way PTGui doesn't have as much of smoothing during the optimization step. I also make sure I include enough overlap and control points so it can do a better job optimizing. Basically my goal with the RAW conversion process is to generate a flat frame and a stitch such that the optimizer in PTGui has as close to a 1 value for the vignetting correction as possible. I also make sure the blending mode is set to eliminate ghosting and I do my own masking in PTGui to eliminate problems areas (clouds, airglow, problematic stars) which can create stitching artifacts. Anyways, I have an album with some of my panos that I've done over the years, about 100 total here and probably not even half of all the ones I've done following this kind of workflow for tracked nightscapes:

 

https://flic.kr/s/aHBqjA9Dom

[sharkmelley]

I picked up a Sony A7C R. It's $1000+ cheaper and for astro purposes shouldn't be missing too much of anything from the RV. Main compromises are the EVF, framerate and buffer which don't really matter for timelapse and tracked shooting. 

 

Due to release date I am sure star eater is gone as well but I can do some tests for Mark to confirm it. 

Thanks for the Sony A7CR test files you sent me.  They are very encouraging.  I need to split the plots across 2 posts because of file sizes.

 

Firstly, let's discuss the raw data filtering (a.k.a. "star eater").  Here is my usual diagram of raw (non-bias-subtracted) pixel values plotted against the maximum of neighbouring values found in the 5x5 block surrounding them:

 

 

You'll notice how similar the plot is to that of the A7R5 in post#3 and how different it is from many of the plots of various "star-eating" cameras here.

 

The important thing about this plot is the strong vertical arm which represents isolated bright pixels.  We are no longer seeing the very destructive effect where pixels brighter than their neighbours all have their value capped to the maximum of their (same colour) neighbours.

 

Just like the A7R5, there are some residual inter-colour-channel effects in the green and blue leading to those fan type "rays".  However, in the case of the A7R5 it did not lead to star damage and I'm confident that the same will be observed with the Sony A7CR.

 

Mark

Edited by sharkmelley, 01 March 2024 - 06:30 PM.