[Igor Sotelo]

Hi there,

I took some pictures of the moon and was started to think how to get into planetary and astro photography.

Soon realised to do everything "right" may need, 3 telescopes, several type of video cameras, expertise in wide variety of applications, a hefty German Equatorial Mount, tripod, computers and a very large number of filters and accessories, for a 5 figures costs.

Before moving in that direction, was wondering if there's a way to try with something simpler first, and recently tried briefly a Pentax K-1, after which I understood many YouTube and Internet reviewers don't really know that much about anything.

So, besides being a solid camera, with functions like the astrotracer maybe the GEM wasn't necessary to start with. And perhaps an composed pixel shift photo could allow for deeper cropping, increasing the reach.

But was wondering what lenses could be good for AP. Was considering the Nikon 14-24mm 2.8G, but the Tamron 15-30mm 2.8 is generally higher rated, specifically for AP, and was wondering if the Pentax-D FA 15-30mm 2.8 is a good lens for AP?

Since the only very sharp normal lens that actually have is 1.8 (Sony Zeiss 55mm 1.8), was also thinking if the Pentax-D FA* 50mm 1.4 should be good for AP?

If the Sigma 35mm 1.4 Art a good option? Will it be good without WR?

Another lens that was considering is the D FA 150-450mm 4.5-5.6, although that one is quite expensive and a bit duplicated by my other photo systems. Too bad EF or F lenses can't be easily adapted to the K mount.

Pentax would be my AP and landscape system.

What should use between 50 and 150.

What lenses are good for going over 450mm without breaking the bank? Is something like the Pentax-K 1000mm f/8 with a 2X TC good for planetary photography, given that it doesn't have ED elements?

Thanks in advance for the information.

[Pentax Syntax]

Astrotracer is good for wide field shots and the lenses you mentioned will all work. The 15-30 DFA is excellent for this type of shot. For planetary imaging,focal length is your friend and a telescope is a near necessity. You can use even a simple doublet refractor or SCT. Many use video capture with a simple webcam imager and average shots with good seeing even with a simple tracking alt-az mount.

[Eye.n.Eye]

Hi Igor,

There is a thread in the groups section where I recently posted documented the astro performance of the Sigma 35mm F1.4:

The Great Astro Lens Test - Astrophotography - PentaxForums.com

In short, I think its the best option for wide field astro on Pentax cameras. I don't think lacking WR is an issue, if its raining, you won't be shooting an astro hahaha

As for the DFA 50mm f1.4, its not particularly good at astro, nor is the recent DFA 85mm unfortunately. Based on my other tests in the thread linked, I'd suggest a film era 50mm f1.4 instead.

Given you mentioned other camera brands, the gold standard for wide field astro on a DSLR is the Sigma 40mm f1.4 ART, however its not available in Pentax mount. If you can go to any camera system, the Sony 24mm GM, 35mm GM and 20mm G are all amazing for wide field astro.

In the 100-150 range on Pentax, the best option is the Samyang 135 f2. Nothing else is even close.

I'll let other people comment on the long lens options, but I assume that the best budget option would be a small telescope (~300mm), and utilise a smaller sensor to get the field of view you need.

Finally, whilst astrotracer is a great function to use when shooting the night sky, I wouldn't be planning on using pixel shift for astro photography. You can achieve an equivalent or better result by just manually stacking multiple normal exposures, with the added benefit of some dithering due to small tracking errors depending on your setup

Either way, good luck, please post your results as you go along for everyone to see!

[HarisF1]

The Rokinon and Samyang lenses are loved by the amateur astrophotography community - I've personally used the Samyang 85 and 135 before with good results.

From the Pentax perspective, I find the DA* 300 is an excellent longer lens. I've used the D-FA 50 at f/2 - 2.8 and it's acceptable if not decent.

[bwgv001]

Maybe this guy is helpful:

You Tube

You Tube

He has a ton of content, also geared towards people with "normal" equipment.

[Postumus]

Here is the LMC with the old SMC 135 F2.5 and a K3, just a tripod and stacked exposures

[Igor Sotelo]

Here is the LMC with the old SMC 135 F2.5 and a K3, just a tripod and stacked exposures

I used to have the SMC Pentax-K 135mm 2.5 in late 70's and early 80's. I think it's an inexpensive lens this days. Do purple fringing and CA affect the results one gets?

Was thinking long time to get a ZF.2 APO Sonnar 2/135, that can be adapted with Leitax products. Though something like the Samyang/Rokinon 135mm 2.0 for PK seems a more reasonable route.

BTW, is the Pentax-D FA* 70-200mm 2.8 recommended for this application?

[Igor Sotelo]

Hi Igor,

There is a thread in the groups section where I recently posted documented the astro performance of the Sigma 35mm F1.4:

The Great Astro Lens Test - Astrophotography - PentaxForums.com

In short, I think its the best option for wide field astro on Pentax cameras. I don't think lacking WR is an issue, if its raining, you won't be shooting an astro hahaha

As for the DFA 50mm f1.4, its not particularly good at astro, nor is the recent DFA 85mm unfortunately. Based on my other tests in the thread linked, I'd suggest a film era 50mm f1.4 instead.

Given you mentioned other camera brands, the gold standard for wide field astro on a DSLR is the Sigma 40mm f1.4 ART, however its not available in Pentax mount. If you can go to any camera system, the Sony 24mm GM, 35mm GM and 20mm G are all amazing for wide field astro.

In the 100-150 range on Pentax, the best option is the Samyang 135 f2. Nothing else is even close.

I'll let other people comment on the long lens options, but I assume that the best budget option would be a small telescope (~300mm), and utilise a smaller sensor to get the field of view you need.

Finally, whilst astrotracer is a great function to use when shooting the night sky, I wouldn't be planning on using pixel shift for astro photography. You can achieve an equivalent or better result by just manually stacking multiple normal exposures, with the added benefit of some dithering due to small tracking errors depending on your setup

Either way, good luck, please post your results as you go along for everyone to see!

Hi Eye.n.Eye,

Thanks for the tips.

Was wondering why the HD D FA* 50mm 1.4 isn’t good for AP? Is the HD D FA* 70-200mm 2.8 or the SMC D FA 77mm 1.8 that was also looking better?

Will check out the Sigma 35mm 1.4 Art, that lens is highly regarded, not only for AP, but I think it needs some modifications to be used with a K-1? Btw, does water condensate on the lenses after some time by night?

It may take time till I get to do some AP. The K-1 II has yet to arrive, and the only K lens so far, is the SMC M 50mm 1.4 that’s on the MX.

[Grimmus]

Will check out the Sigma 35mm 1.4 Art, that lens is highly regarded, not only for AP, but I think it needs some modifications to be used with a K-1? Btw, does water condensate on the lenses after some time by night?

It may take time till I get to do some AP. The K-1 II has yet to arrive, and the only K lens so far, is the SMC M 50mm 1.4 that’s on the MX.

Have also heard nothing but good reports on the Sigma 35 mm. Condensation is usually solved by using a lens warmer - cheap ones available on fleabay. Suggest you have a good read through the the Astrophotography group on this forum. Lots of information there, and inspiration! Member PeteXL has done some ridiculously good stuff with a 50 mm lens (and trackers and dedicated astro cameras) and Mossyrocks regularly runs vintage 50 mm's. Most of the old 50's seem to perform well at f2.8.

[HarisF1]

The D-FA suffers from coma at wider apertures. I'd usually look to using it stopped down a bit so that shouldn't be too much of an issue.

When it comes to the Samyang 135/2, I don't think I've come across a sharper lens across the frame. It's immense from wide open and the edges are excellent too.

As a side note, the 135's ability to capture information surgically also makes it quite a boring lens to use - it lacks character for normal shooting.

[Eye.n.Eye]

Hi Eye.n.Eye,

Thanks for the tips.

Was wondering why the HD D FA* 50mm 1.4 isn’t good for AP? Is the HD D FA* 70-200mm 2.8 or the SMC D FA 77mm 1.8 that was also looking better?

Will check out the Sigma 35mm 1.4 Art, that lens is highly regarded, not only for AP, but I think it needs some modifications to be used with a K-1? Btw, does water condensate on the lenses after some time by night?

It may take time till I get to do some AP. The K-1 II has yet to arrive, and the only K lens so far, is the SMC M 50mm 1.4 that’s on the MX.

The DFA 50mm struggles with aberrations off axis wide open (so the starts will not be points of light in the corners). I've included a review of this lens for astro at the end of my post. the long and the short is that once stopped down to f2.8 it should be looking good, but at that aperture, the M 50mm f1.4 that you already own will be looking just as good. That's the lens I'd be focussing on practising with if I was you.

The 70-200mm f2.8 should work well for astro. I've included another link, showing the coma performance of the Tamron version of this lens. I haven't used this lens, but I've used the second generation Tamron 70-200mm on another mount, and its one of the most impressive lens I've ever used around.

I don't have any info on the 77 f1.8 for astro, but my expectation would be thats its not great. This is based on its coma performance reported on Lenstip, also linked at the end of this post.

Regarding the Sigma 35mm f.4 it definitely works as is on the K1. I think it may have scratched the original K1 body very slightly above the lens mount, but I use a K1ii and I've never even seen a mark at all. In very cold conditions, I wrap a USB powered lens warmer around the 35mm to prevent condensation. I do this on every lens, its not specific to the Sigma 35mm, nor is it something that Pentax WR will prevent.

So once you get the K1ii, go out and practice with Pentax-M 50mm you already own, whilst you decide between the Sigma 35mm or the Samyang 135mm as your astro specific lens purchase (why not both hahaha).

Pentax D FA? 50mm f/1.4 Review - MilkyWayPhotographers.com
Tamron SP 70-200 mm f/2.8 Di VC USD review - Coma, astigmatism and bokeh - LensTip.com
Pentax smc FA 77 mm f/1.8 Limited review - Coma and astigmatism - LensTip.com

[angerdan]

1. So, besides being a solid camera, with functions like the astrotracer maybe the GEM wasn't necessary to start with. And perhaps an composed pixel shift photo could allow for deeper cropping, increasing the reach.
2. But was wondering what lenses could be good for AP. Was considering the Nikon 14-24mm 2.8G, but the Tamron 15-30mm 2.8 is generally higher rated, specifically for AP, and was wondering if the Pentax-D FA 15-30mm 2.8 is a good lens for AP?
3. Since the only very sharp normal lens that actually have is 1.8 (Sony Zeiss 55mm 1.8), was also thinking if the Pentax-D FA* 50mm 1.4 should be good for AP?
4. If the Sigma 35mm 1.4 Art a good option? Will it be good without WR?
5. Another lens that was considering is the D FA 150-450mm 4.5-5.6, although that one is quite expensive and a bit duplicated by my other photo systems. Too bad EF or F lenses can't be easily adapted to the K mount.
6. What lenses are good for going over 450mm without breaking the bank? Is something like the Pentax-K 1000mm f/8 with a 2X TC good for planetary photography, given that it doesn't have ED elements?

1. For increasing the reach, i'd rather prefer the K-3 III with it's phantastic APS-C image sensor instead of the 2016 best available K-1 FF camera.
   And then you can profit from the perfect astro lens DA* 11-18mm f2.8 whose exterior is designed with a lens heater groove to prevent dew condensation.
   Product Overview | HD PENTAX-DA?11-18mmF2.8ED DC AW | PENTAX STAR LENS | RICOH IMAGING
2. The Pentax D FA 15-30mm 2.8 is identical to the Tamron. It's quality is unquestionable.
3. The D FA* 50mm 1.4 is one of the best AF 50mm primes and the Tokina Operia is identical. You can use it wide open.
4. The Sigma 35mm Art offers high image quality at open aperture. If you wait until 2022, a Pentax D FA* 35mm prime might be announced (it's already on the Pentax lens roadmap). Remember Pentax offers native DNG in all cameras!
5. The D FA 150-450mm offers much image quality for it's price tag and can compete with most competitors regarding fast aperture. If you switch from your other photo systems to Pentax, you'll even save money
6. How high is the budget on your bank? If the D FA 150-450mm is out of your reach, the next 400mm option is a ised K 400mm f5.6.
   <= 2990g Full Frame Lenses | PentaxForums.com

[Igor Sotelo]

1. For increasing the reach, i'd rather prefer the K-3 III with it's phantastic APS-C image sensor instead of the 2016 best available K-1 FF camera.
   And then you can profit from the perfect astro lens DA* 11-18mm f2.8 whose exterior is designed with a lens heater groove to prevent dew condensation.
   Product Overview | HD PENTAX-DA?11-18mmF2.8ED DC AW | PENTAX STAR LENS | RICOH IMAGING
2. The Pentax D FA 15-30mm 2.8 is identical to the Tamron. It's quality is unquestionable.
3. The D FA* 50mm 1.4 is one of the best AF 50mm primes and the Tokina Operia is identical. You can use it wide open.
4. The Sigma 35mm Art offers high image quality at open aperture. If you wait until 2022, a Pentax D FA* 35mm prime might be announced (it's already on the Pentax lens roadmap). Remember Pentax offers native DNG in all cameras!
5. The D FA 150-450mm offers much image quality for it's price tag and can compete with most competitors regarding fast aperture. If you switch from your other photo systems to Pentax, you'll even save money
6. How high is the budget on your bank? If the D FA 150-450mm is out of your reach, the next 400mm option is a ised K 400mm f5.6.
   <= 2990g Full Frame Lenses | PentaxForums.com

Unfortunately, I’m not a big fan of APS-C. The K-3 III is quite expensive and won’t be available used for a while, doesn’t have GPS and I’m not sure if it has the same tilt-shift screen of the K-1 II.

Since the difference between 35mm and 50mm isn’t big, I think that may go with the D FA 15-30mm 2.8, D FA* 50mm 1.4 and the D FA 150-450mm 4.5-5.6 setup.

Plus something in between 50 and 150mm, to have a complete setup. Could be the D FA 100mm 2.8 macro, the D FA* 70-200mm 2.8 or the Rokinon 135mm 2.0?

Though, will go gradually over a period of time, with perhaps the 15-30mm first.

[angerdan]

The K-3 III is quite expensive and won’t be available used for a while, doesn’t have GPS and I’m not sure if it has the same tilt-shift screen of the K-1 II.

The K-3 III is worth every penny and as cheap as every new APS-C flagship from Pentax.

It is already available used since a while and does support GPS without the need for O-GPS1.
The APS-C flagships are always without tilting display. Besides the fullsize K-1 only the Entry and medium range models have fully articulated or tilting displays.

[slartibartfast01]

The K-3 III is worth every penny and as cheap as every new APS-C flagship from Pentax.

It is already available used since a while and does support GPS without the need for O-GPS1.

It doesn't support Astrotracer without the 0-GPS1 though.