66 replies to this topic

[PeterWar]

Maybe cheaper than Spain but I somehow doubt it's that much better priced than US. I had a friend recently go to Japan and he said the prices weren't that much better. 

 

In any case even with 1-2k off I don't think a 300 GM is in the budget or I would get enough use to justify it. 

 

Leaning towards trying the Nikon. 

The lens was 40% cheaper in MapCamera Tokyo and that makes a difference, maybe US prices will be different indeed.

 

I've used APP to combine data of 3 nights on the Pleyades, two made with A7III camera, the Nikor 300mm f2.8 and the other with the Sony 300mm GM 2.8 under semirural skies.

 

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Above is 880x15seconds of M31 under suburban skies using the staradventurer and the Sony 300mm f2.8 GM, no dithering, no tracking, no computer involved, just a grap-and-go setup.


I'm leaving for Namibia tomorrow, can't wait to try this lens with and without 1.4x 2x telecompressors, any souther sky objects you would recommend I photograph?

Edited by PeterWar, 16 May 2025 - 01:31 PM.

[Shubham]

Great images Peter! You could image the Carina along with Statue of Liberty nebula in one frame, the LMC & Tarantula complex, the SMC and the two globular clusters nearby (one of them is REALLY big!) and/or the Centaurus-A galaxy with Omega Centauri. I think the first two would be the most rewarding but the last two would also be great if you get more time (in addition to the first two).

Edited by Shubham, 16 May 2025 - 02:07 PM.

[PeterWar]

Great images Peter! You could image the Carina along with Statue of Liberty nebula in one frame, the LMC & Tarantula complex, the SMC and the two globular clusters nearby (one of them is REALLY big!) and/or the Centaurus-A galaxy with Omega Centauri. I think the first two would be the most rewarding but the last two would also be great if you get more time (in addition to the first two).

 

Here it is — the Carina Nebula captured at 122mm f/2.8 using my Sony FE 70-200mm GM OSS II. This image is the result of 87 exposures of 12 seconds each (I couldn’t go longer since I struggled to precisely align with the southern celestial pole — still getting used to these skies). In total, that’s about 20 minutes of integration time, all taken with my unmodified A7RIII-A on a Star Adventurer mount.

 

And yes, in true five-monkey-experiment fashion, I must remind you: Never use a variable focal length lens! always image at F4, guide and dither, that way you'll need twice the time to do less 

[Shubham]

 

Here it is — the Carina Nebula captured at 122mm f/2.8 using my Sony FE 70-200mm GM OSS II. This image is the result of 87 exposures of 12 seconds each (I couldn’t go longer since I struggled to precisely align with the southern celestial pole — still getting used to these skies). In total, that’s about 20 minutes of integration time, all taken with my unmodified A7RIII-A on a Star Adventurer mount.

 

And yes, in true five-monkey-experiment fashion, I must remind you: Never use a variable focal length lens! always image at F4, guide and dither, that way you'll need twice the time to do less 

Excellent results Peter, for just 20min of exposure! Stars look round all the way to the edge! I can imagine the frustration aligning to the southern pole lol. Really can't complain. Except maybe the green-ish artifacts generated by the camera. Sonys used to have that problem, but the recent cameras seem to have fixed it.

 

Right on on that conclusion! I can't wait for the day to have the Sony 50-150 f/2, that lens would do wonders in the dark. Really upto 300mm fast lenses are the best!

[PeterWar]

Thanks, I’ve found that SNCR green in pixinsight does wanders in removing the dreaded green tint, this are quick captures of objects I expect to do much better in the next two weeks…

[Shubham]

Looking forward to it!

[PeterWar]

Looking forward to it!

 

There you go, a quick 110x15sec exposures of the trifid nebula &co done with my staradventurer 2i at Tivoli, I had to trow away 3-5 subs, done with Sony 300mm f2.8 GM+ A7RIIIA unmodified camera. I really did not do much postporcessing as I don't have the time, just 0.7 SNR green in pixinsight and GradXpert to remoce the gradient, although it did very, very little.

 

What's interesting is that I did NOT use darks or lights in APP to callibrate anything, I really don't see their use anymore, just keep the sensor clean, AI tools are getting much better at removing light gradients, noise is a Non-issue with this method of working as NoiseXterminator does very little to improve things.

 

And yes, in true five-monkey-experiment fashion, I must remind you: always keep a set of fresh 101 darks, flats, dark-flats when callibrating your x2-4 slower images done at multiple different temperatures and with the refractors working at f4.5-f6, that whay you will waste more time and you will age your CMOS or CCD sensor quicker, allowing for more hot pixels and missing columms that will add extra fun and require interpolating exercices when post-processing.

This will allow you to be much less efficient, but in line with tradition, common wisdom and convention. If you don't agree with this you really must be new to the hobby.

Edited by PeterWar, 22 May 2025 - 04:05 PM.

[Shubham]

 

There you go, a quick 110x15sec exposures of the trifid nebula &co done with my staradventurer 2i at Tivoli, I had to trow away 3-5 subs, done with Sony 300mm f2.8 GM+ A7RIIIA unmodified camera. I really did not do much postporcessing as I don't have the time, just 0.7 SNR green in pixinsight and GradXpert to remoce the gradient, although it did very, very little.

 

What's interesting is that I did NOT use darks or lights in APP to callibrate anything, I really don't see their use anymore, just keep the sensor clean, AI tools are getting much better at removing light gradients, noise is a Non-issue with this method of working as NoiseXterminator does very little to improve things.

 

And yes, in true five-monkey-experiment fashion, I must remind you: always keep a set of fresh 101 darks, flats, dark-flats when callibrating your x2-4 slower images done at multiple different temperatures and with the refractors working at f4.5-f6, that whay you will waste more time and you will age your CMOS or CCD sensor quicker, allowing for more hot pixels and missing columms that will add extra fun and require interpolating exercices when post-processing.

This will allow you to be much less efficient, but in line with tradition, common wisdom and convention. If you don't agree with this you really must be new to the hobby.

Another awesome image Peter! I’m actually impressed you only had to throw a couple frames even at 300mm with the SA. That’s really cool!

 

I’d be interested in learning how long can one go in their subs with this setup and still be able to keep more than 80% of the frames with no star trails. Can you try 30, 40 & 60s if you get time?

[vidrazor]

What's interesting is that I did NOT use darks or lights..

Impressive.
 

[PeterWar]

Impressive.
 

 

I'm very glad that vidrazor felt alluded-to reply and stepped-in to correct my lapsus, I meant to say I did NOT use darks or FLATS in APP to callibrate anything, thanks for enlighting me vidrazor, hopefully that will contribute to my posts being a little bit less incomprehensible to real experts  . The Trifid nebula is visible from mostly everywhere in the world now, so I would be very interested to see your results with your setup.

 

Another awesome image Peter! I’m actually impressed you only had to throw a couple frames even at 300mm with the SA. That’s really cool!

 

I’d be interested in learning how long can one go in their subs with this setup and still be able to keep more than 80% of the frames with no star trails. Can you try 30, 40 & 60s if you get time?

I will be glad to try that when I get back home in the northern hemisphere, honestly I dare not shoot longer integration times as the southern celestrial pole is very hard to get right and I worry field rotation might affect longer subs.

The 2i revision of the staradventurer added a bunch of unecessary things but it weights 50g more, this might contribute in adding some stability.

Edited by PeterWar, 23 May 2025 - 08:07 AM.

[vidrazor]

I'm very glad that vidrazor felt alluded-to reply and stepped-in to correct my lapsus, I meant to say I did NOT use darks or FLATS in APP to callibrate anything, thanks for enlighting me vidrazor, hopefully that will contribute to my posts being a little bit less incomprehensible to real experts  . The Trifid nebula is visible from mostly everywhere in the world now, so I would be very interested to see your results with your setup.

I'm happy you're getting the imaging you're getting, just having a little fun with your comment.

 

I don't normally shoot wide like you do, and have had some bad times trying to shoot anything, so I haven't shot much.

 

I will say however that, although capturing IFN is a recent hobby many have been hot to capture, while interesting, I don't find them particularly attractive. You image here is a perfect example. Compared to the nebulae and stars, it's monochromatic dust. Nebulae, galaxies, and stars have color and life, IFN is essentially "space junk".

 

At least, that's my take on it. I know many are hot to capture IFN, now that they've realized A) it's there and B) they can readily capture it with standard gear.
 

[Shubham]

I will say however that, although capturing IFN is a recent hobby many have been hot to capture, while interesting, I don't find them particularly attractive. You image here is a perfect example. Compared to the nebulae and stars, it's monochromatic dust. Nebulae, galaxies, and stars have color and life, IFN is essentially "space junk".

 

At least, that's my take on it. I know many are hot to capture IFN, now that they've realized A) it's there and B) they can readily capture it with standard gear.
 

I mean you can see the nebula pretty clearly there AND the dark dust lanes. It’s not really monochromatic, but has subtle hues. I’d take seeing something that is there, vs not seeing it, any time of the day.

[vidrazor]

I mean you can see the nebula pretty clearly there AND the dark dust lanes. It’s not really monochromatic, but has subtle hues. I’d take seeing something that is there, vs not seeing it, any time of the day.

Like I said, some people like it. Go for it.
 

[PeterWar]

Like I said, some people like it. Go for it.
 

A side note, I don't think the photo of the Trifid Nebula contains IFN, when you mentioned it I thought it was correct, but after some investigation I see that this image does not contain Integrated Flux Nebula (IFN) because it captures a region near the galactic core in Sagittarius, where dense star fields, emission nebulae, and dark molecular clouds dominate the scene. IFN is typically found at high galactic latitudes, far from the bright central plane of the Milky Way, and appears as faint, wispy reflections of the galaxy’s combined starlight against a dark sky. I could be wrong though.

[xonefs]

After much deliberation I just ordered a used nikon 300mm f2.8 ED II for Namibia. Hopefully the optics are good. I was debating between that and renting a 300mm gm but for 1 month rental it would cost almost as much as just buying the nikon so hopefully it's good enough. 

[PeterWar]

After much deliberation I just ordered a used nikon 300mm f2.8 ED II for Namibia. Hopefully the optics are good. I was debating between that and renting a 300mm gm but for 1 month rental it would cost almost as much as just buying the nikon so hopefully it's good enough. 

You will not regret the purchase, its an excelent lens, I suspect it's slightly better in some aspects to the 300mm gm, particularly on very bright stars off axis. Please show your results, I can share some raws as well to compare quality among different lenses of the same model.

[xonefs]

I'm happy with it. Also rigged it up with a belt to an EAF so definitely better to use that way. Focus shifts on cold desert nights. Have had good results with the 1.7x TC too. And fits a 52mm ids nbz in the filter holder unlike the sony 43mm slot. 

 

 

 

 

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