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SL2-S for astro


Alistairm
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Sure. All kinds of things. For instance: is there substantially less noise with the new sensor than with, say, the sensor of an SL, or an M10, or a TL2?  How much? Can the difference be expressed in terms of  f-stops (that is: Does the new sensor have similar noise at ISO 12500 to what the SL sensor had at ISO 3200, for example -- so a two stop improvement)? So, will an ISO 12500 look as good as 3200 used to look? Or is it one stop better? -- or . . .  you get the idea.

In practical terms, could one use a higher ISO (and therefore) lower shutter speed for astrophotography (thus reducing star movement without gaining any noise)?  Or, alternatively, will it give me results formerly available only at f/2 at f/4 now? (Stars are often sharper at f/4 than at f/2).

Does the SL2 limit the length of a time or bulb exposure according to ISO? Does it limit exposure time at all? If so, to what?

And lastly, should I buy one to use with my old R zooms?😎

Edited by bcorton
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7 hours ago, bcorton said:

Sure. All kinds of things. For instance: is there substantially less noise with the new sensor than with, say, the sensor of an SL, or an M10, or a TL2?  How much? Can the difference be expressed in terms of  f-stops (that is: Does the new sensor have similar noise at ISO 12500 to what the SL sensor had at ISO 3200, for example -- so a two stop improvement)? So, will an ISO 12500 look as good as 3200 used to look? Or is it one stop better? -- or . . .  you get the idea.

In practical terms, could one use a higher ISO (and therefore) lower shutter speed for astrophotography (thus reducing star movement without gaining any noise)?  Or, alternatively, will it give me results formerly available only at f/2 at f/4 now? (Stars are often sharper at f/4 than at f/2).

Does the SL2 limit the length of a time or bulb exposure according to ISO? Does it limit exposure time at all? If so, to what?

And lastly, should I buy one to use with my old R zooms?😎

The short answer is that the SL2-S is the only Leica body I would bother considering for astrophotography. The M10 is not even an option due to limited shutter length at high ISO. The SL2-S has a 2-3 stop advantage over the SL and SL2. I think probably get the idea. To me, it’s the first and only Leica body that can take decent photos of the Milky Way without a star tracker and stacking photos in post.

 The thing to keep in mind is that practically speaking, you need a shutter speed of <15s to avoid smearing of stars due to earth rotation if you’re not using a tracking mount. That being said, SL, SL2, SL2-S have a 30min max shutter duration.

 Personally, R zooms and most R lenses are overrated. Modern glass have come a long way. Sigma makes some very sharp lenses are very reasonably prices. The Sigma 14-24 f/2.8 Art DG DN is one of the best lenses on the market for astrophotography.

Here’s a recent shot. Post #714 

 

Edited by beewee
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11 hours ago, beewee said:

The short answer is that the SL2-S is the only Leica body I would bother considering for astrophotography. The M10 is not even an option due to limited shutter length at high ISO. The SL2-S has a 2-3 stop advantage over the SL and SL2. I think probably get the idea. To me, it’s the first and only Leica body that can take decent photos of the Milky Way without a star tracker and stacking photos in post.

 The thing to keep in mind is that practically speaking, you need a shutter speed of <15s to avoid smearing of stars due to earth rotation if you’re not using a tracking mount. That being said, SL, SL2, SL2-S have a 30min max shutter duration.

 Personally, R zooms and most R lenses are overrated. Modern glass have come a long way. Sigma makes some very sharp lenses are very reasonably prices. The Sigma 14-24 f/2.8 Art DG DN is one of the best lenses on the market for astrophotography.

Here’s a recent shot. Post #714 

 

beewee,

Thanks for the answer and the link to the beautiful example. 

You are correct that lens design and production have advanced since the R days. But if I sprung a financial leak for the SL2s, it would pretty much drain the reservoir and I'd be stuck using it with R glass since that is what I have -- well, that and M, mostly Mandler.  

Currently, I am solidly stocked in the APS-C format (TL2 and many lenses -- Leica and Sigma). I do own the Sigma 14-24, and it is, as you say, a wonderful astrophotography lens -- even using it cropped on the TL2. Of course, setting exposure time in order to avoid star trails depends on many things: lens angle primarily, but also on how close the target is to the celestial equator, sensor size, and even pixel pitch to a degree. But <15 seconds is a good rule of thumb for a wide angle lens. The posted photo (20 sec.) is a quick example, but I cannot remember the focal length setting. I find the TL2 does pretty well, as it can be kept open to 30 sec. at all ISOs, but was wondering how much easier the SL2s might make things. Then there is also the issue of FF vs. cropped. FF would be nice.

But since I don't do this professionally, I have a hard time justifying the outlay for a new system. I may wait until the next APS-C iteration from Leica to see if they implement a BSI sensor in a new TL or CL. Then I could just keep the current complement of lenses and sell off the R kit. But then again . . . .🤔 I'm interested in seeing Mike's take and examples as well.

Again, thanks,

Brent

 

Edited by bcorton
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5 hours ago, bcorton said:

beewee,

Thanks for the answer and the link to the beautiful example. 

You are correct that lens design and production have advanced since the R days. But if I sprung a financial leak for the SL2s, it would pretty much drain the reservoir and I'd be stuck using it with R glass since that is what I have -- well, that and M, mostly Mandler.  

Currently, I am solidly stocked in the APS-C format (TL2 and many lenses -- Leica and Sigma). I do own the Sigma 14-24, and it is, as you say, a wonderful astrophotography lens -- even using it cropped on the TL2. Of course, setting exposure time in order to avoid star trails depends on many things: lens angle primarily, but also on how close the target is to the celestial equator, sensor size, and even pixel pitch to a degree. But <15 seconds is a good rule of thumb for a wide angle lens. The posted photo (20 sec.) is a quick example, but I cannot remember the focal length setting. I find the TL2 does pretty well, as it can be kept open to 30 sec. at all ISOs, but was wondering how much easier the SL2s might make things. Then there is also the issue of FF vs. cropped. FF would be nice.

But since I don't do this professionally, I have a hard time justifying the outlay for a new system. I may wait until the next APS-C iteration from Leica to see if they implement a BSI sensor in a new TL or CL. Then I could just keep the current complement of lenses and sell off the R kit. But then again . . . .🤔 I'm interested in seeing Mike's take and examples as well.

Again, thanks,

Brent

 

The TL2 is a decent body for astro. In fact the low noise performance is actually similar to the SL2-S except there’s a bit of built-in noise reduction baked in at high ISO as compared to the SL2-S which has no noise reduction baked in.

Here’s a comparison on Photons to Photos: https://photonstophotos.net/Charts/PDR.htm#Leica CL,Leica SL2,Leica SL2-S,Leica TL2

I think the biggest limiting factor with APS-C is the lack of reasonably fast (i.e. f/2.8) ultra-wide lenses (<18mm FF equiv.) options on the market, especially for L-mount which makes it very hard to capture wide field milky way photos on the TL2. Since you have the 14-24, that would be my go-to lens for astro if you get the SL2-S. For normally shooting, I’m not sure what is your primary subject but the Sigma i-series primes are very high performers and very reasonably priced. I have the 24mm f/3.5 DG DN and it is sharp to the corners stopped down even when using 100 MP multi-shot mode. Very impressive for a $500-600 lens. So if you’re into shooting primes, then that’s a great option. Otherwise, the Sigma 28-70 is also another good option.

If you were to wait for another APS-C body to come along, there are rumors of the CL2 but I don’t know when it’ll actually be released. There’s also rumors that the M11 will be announced on Nov 11, 2021 but I expect it will take some more time for bodies to be available and even then, it may take many months before supply catches up with demand and you can get one somewhat easily.

 

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If I’m going to do much astrophotography, it makes sense to stay with the L-mount (or switch to a different camera brand). I love my M6 and all, but my older Mandler-mostly glass is not the best for Astro. The new designs are too expensive, I’m afraid. I’d rather my daughter goes to college. 😉

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11 hours ago, bcorton said:

If I’m going to do much astrophotography, it makes sense to stay with the L-mount (or switch to a different camera brand).

If you’re not married to Leica, the Panasonic S5 is a much more affordable option and will work with L-mount. The sensor is nearly identical to the SL2-S in dynamic range and high ISO response. So it boils down to what design, budget, and user interface you prefer.

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Since everyone is being so nice as to recommend cameras to me, I feel I should say that I didn't mean to hijack this thread and take it into "let's help Brent pick a camera" territory. Brent is going to stick with his TL2 until he sees a clear way forward. Meanwhile, thanks for your kindness, but mostly I want to learn here more about the SL2s and its astrophotography capabilities. 

The "Photons to Photos" page beewee linked to does suggest that noise between the SL2s and the TL2 is similar at ISO 3200, because some noise reduction is "baked into" the TL2's processing. But I have a hard time believing that the newer and backlit sensor of the SL2s wouldn't be an advantage, especially after doing my own noise reduction. No?

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51 minutes ago, bcorton said:

I have a hard time believing that the newer and backlit sensor of the SL2s wouldn't be an advantage, especially after doing my own noise reduction. No?

Correct. The SL2-S should have an advantage over the TL2 given that the dynamic range curve you see on Photons to Photos for the SL2-S is before any noise reduction. This implies that, in post processing, you can apply further noise reduction to taste. In contrast, the Photons to Photos dynamic range curve for the TL2 is after some internal noise reduction performed by the camera and baked into the raw file. Further noise reduction can be applied in post processing but you may not gain as much improvement or there may be more losses in the image quality as a result.

I say should in the above paragraph since I don’t have any experience with a TL2 so it’s not something I can say with any personal experience or direct data.

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Yup. That was pretty much my thinking too.  Thanks.

It would be enlightening to see some specific data or some direct comparisons between older sensors’ performances vs the new. But that is probably too much to hope for. 

Edited by bcorton
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That’s interesting. For astro, 8 second exposure multi-shot is not really necessary but a 2-3 second exposure would make sense. 8x 2s exposure would be equivalent to a 16s single exposure as far as light gathering go and the multi-shot is basically doing in-camera stacking which does reduce overall noise. Maybe that’s something Leica can add as a feature in future FW.

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20 minutes ago, beewee said:

For astro, 8 second exposure multi-shot is not really necessary

I’ll correct myself on this one. One area where having 8s exposure for multi-shot may bring value would be for combining separately exposed foreground and sky images which is fairly common practice in astro. So, if one wanted to expose the foreground separately, an 8x8s multi-shot exposure for a combined 64s exposure may also open up new possibilities.

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Unfortunately my plans to try out astro photography with my new SL-2S were put on hold for a couple of days due to her presence 👇

Zuka Game Reserve, South Africa,  SL-2S & Canon 400mm f4 USMll DO & Canon 400mm 1.4 x TC w/Sigma MC-21 converter.

Hand held ISO100 f8 @ 1/250s Electronic shutter (please click on image for better res.)

 

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18 hours ago, bcorton said:

That's lovely, Lucio. 

Would you be willing to share some of the metadata with the forum (ISO, shutter speed, focal length and aperture)?

Certainly ..... VE 24-90 on 24mm - f/2,8 - ISO 1.600 - foreground t/5 sec - sky n.3 shots 300 sec with astro tracker combined with AstroPanel 

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15 hours ago, michali said:

Unfortunately my plans to try out astro photography with my new SL-2S were put on hold for a couple of days due to her presence 👇

Zuka Game Reserve, South Africa,  SL-2S & Canon 400mm f4 USMll DO & Canon 400mm 1.4 x TC w/Sigma MC-21 converter.

Hand held ISO100 f8 @ 1/250s Electronic shutter (please click on image for better res.)

 

Ah, the moon. “Roving light pollution” someone called it. 
Actually that is quite the impressive lunar photo — even more so since it is hand-held. Kudos. 

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