Kiwi Pentaxians

**pixelsaurus** · 04-07-2017, 12:23 AM

Originally posted by GUB

So you mean Low exposures rather than shutter time and saturation as in heading towards overexposure?

The problem with astrophotography is that the night sky has a huge dynamic range, probably in the range of 1:squillions. No film or digi sensor can adequately cover it. Sometimes those digi astrophotog fellas will shoot some short exposures (records star colours but with little background detail) to stack along with their longer exposure frames (overexposed bright stars but plenty of background detail). It helps to preserve the colour in the stars.

Rolf does a good job in that respect.

Nebulae - rolfolsenastrophotography

Jerry has words to say as well: Recording and Enhancing Star Colors

You can buy actions for PS to pull out star colour as well.

Enterprise Astronomy & Photography | Annie's Astro Actions

Astronomy Tools Actions Set by ProDigital Software

**GUB** · 04-07-2017, 04:26 AM

Originally posted by pixelsaurus

The problem with astrophotography is that the night sky has a huge dynamic range, probably in the range of 1:squillions. No film or digi sensor can adequately cover it

Yeah and then comes the trade off -do you have a billion stars in your shot and suffer the brighter ones burning themselves up to an unnatural size or do you put up with less stars in your image coz the little ones havent triggered the sensor

Kiwi645hauler · 04-07-2017, 03:44 PM

Originally posted by GUB

So you mean Low exposures rather than shutter time and saturation as in heading towards overexposure?
I have discovered I am colour insensitve in the red cyan line like a lot of older men. Funnily enough it has only proven to be a problem doing black and white printing.!

What he means is use lots of short exposures ie 10x 15s exposures rather than 4x 60s exposures. the shorter exposure times keep the star colors correct and make it easier to stack images as the stars havent started to really trail

**GUB** · 04-07-2017, 06:24 PM

Originally posted by Kiwi110Auto

What he means is use lots of short exposures ie 10x 15s exposures rather than 4x 60s exposures. the shorter exposure times keep the star colors correct and make it easier to stack images as the stars havent started to really trail

So In astro stacking the underexposures are added up to increase exposure. ? This doesn't happen in normal focus stacking does it?

**pixelsaurus** · 04-07-2017, 11:47 PM

Originally posted by GUB

So In astro stacking the underexposures are added up to increase exposure. ?

Yes. The shorter exposures also assist in controlling noise. Most astros seem to shoot in roughly 3 minute exposures for faint objects. Longer exposures as well as burning out the stars, also generates noise. There is a law of diminishing returns for exposure and it seems beyond 3 minutes offers little benefit. For the brighter DSO's (Deep Sky Objects such as the Great Nebula in Orion), they include exposures down to 5 secs or so in the stack. Some astros such as Rolf Wahl Olsen and Sara Wager, to mention two, often stack images where the total exposure runs to over 100 hours. Of course they don't use DSLR's but dedicated monochrome CCD cameras and narrow band filters.This is a whole different type of photography.

Originally posted by GUB

This doesn't happen in normal focus stacking does it?

I would hazard a guess and say things like Helicon Focus and Zerene Stacker use different criteria to stack. Maybe something to do with contrast.

**NZ_Ross** · 04-08-2017, 12:06 AM

Originally posted by richandfleur

What sort of things did you eventually come to change with the K-3 over your previous behaviours with the K-5?

Hi Richard,

I think there were a couple of main observations -

The K-3 has no AA filter and the 24MP sensor, compared with the 16MP AA'ed sensor of the K-5.

The first thing I had to get used to is a 24MP no AA filter sensor output does not look good if you slightly miss focus or get anything in that area wrong. Some of my best lenses - the Zeiss and Voigtlander lenses are manual focus, so slightly missed focus is a distinct possibility. So I learnt to take more care - more shot discipline should I say. When it is spot on the images are fantastic, when you ever so slightly get it wrong you really notice.

Secondly, the RAW files from the K-3 appear 'flat' when compared with the K-5 files - I think again this is just the different sensors and RAW convertor setup. The is clearly a lot more information in the K-3 files, but it took a bit of getting used to in terms of the change, and just some slightly different post processing techniques. What I can say is that you have more post processing 'head room' with the K-3 files. Once I got used to what I could do with the files I was a lot happier. Part of this is also the ability to crop more if you want to with the K-3 files.

At the heart of noticing the differences was I had got very used to the K-5, how to shoot it, how to post process and get images I was happy with. It just took a few months to get used to the K-3, that you could do things subtly different, that you could shoot a scene and then bring up a lot more info in post processing - that sort of thing. I am now very well used to the K-3 and generally very happy with the images it gives me. When I am not happy, it is me that is at fault, not the camera - I have mucked something up generally.

Handheld I shoot TAv, with SR on, and AA filter simulation off.

I trust this helps with your enquiry.

Cheers

Ross

awa355 · 04-08-2017, 12:35 AM - **3 Likes**

I picked up on the different engine note today. It was way up in the air (I suppose it is meant to be)

I had to crop the bejeezus out of it to get any details. Not sure what animal it is. One of you lot will know.

Also attended a horse event today. The pentax is not brilliant at jpegs but I'm happy with these shots.

Attached Images

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richandfleur · 04-08-2017, 12:52 AM

Thanks Ross,

The K-3 deal hasn't gone through, as the seller decided he couldn't part with it. I get that, so am now back on the hunt.

Interesting comments Ross, as I've been through something similar moving from the K-30 to the K-S1, which is a similar 16MP AA filter to 20MP AA filterless jump.

Kiwizinho · 04-08-2017, 03:14 AM

I think I'm beginning to lust after a DA 50-135 2.8.
I did some family portraits for some friends today, and used the FA 50 1.4 and Tamron 90 2.8 macro, and while both are great portrait lenses, changing between them was a pain. The Tamron 70-200 2.8 also looks like a good option, but is maybe not quite wide enough. The DA 50-135 seems like it was designed with portraits in mind. It will be a while till I can afford it, and there's some other stuff I'd like as well such as flash and reflector stands, and some more external flashes. At least my wife did a pretty good job as a reflector stand. The reflector itself got its first proper outing, and had to be one of my most economical photography acquisitions. I think I paid $16 for a 5 in 1 reflector on Tradme. Taking good group portraits is hard work, especially with kids involved!
Even with all the proliferation of smartphones and selfies, a really good group portrait is a real challenge.
I've mostly stuck to landscapes and natural history because they feel like 'safe' subjects, but portraits really push the limits in terms of having the right equipment and skills.
I'm naturally a bit of an introvert, so having subjects that you need to talk into cooperating is challenge, but after seeing results that are likely beyond the limits of any smartphone, I'm going to want to do more of this.

**Clarkey** · 04-08-2017, 05:40 AM

Originally posted by awa355

I picked up on the different engine note today. It was way up in the air (I suppose it is meant to be)

I had to crop the bejeezus out of it to get any details. Not sure what animal it is. One of you lot will know.

Also attended a horse event today. The pentax is not brilliant at jpegs but I'm happy with these shots.

Very good - nice, clear looking shots.
Blast from my past - I used to do this sort of thing.

**pixelsaurus** · 04-08-2017, 06:19 AM

Originally posted by awa355

I picked up on the different engine note today. It was way up in the air (I suppose it is meant to be)

I had to crop the bejeezus out of it to get any details. Not sure what animal it is. One of you lot will know.

Maybe one of these: Mitsubishi MU-2 - Wikipedia

https://www.caa.govt.nz/script/air-reg-query/

Class A · 04-09-2017, 07:11 AM

Originally posted by richandfleur

The K-3 deal hasn't gone through, as the seller decided he couldn't part with it. I get that, so am now back on the hunt.

Why don't you wait until a model receives hardware-based video stabilisation (either from the get go or through a firmware update)?

Or get a K-5 II?

Transit · 04-09-2017, 12:53 PM

or my K-5iis

15k on the shutter...unmarked

Kiwi645hauler · 04-09-2017, 04:34 PM

Woo... less than 1 week to Classic Fighters Omaka, I leave Dunedin Wednesday afternoon with an overnight stop in CHCH, then on to Blenheim Thursday. Camera bags are packed, film stocked up and ready to go.

richandfleur · 04-09-2017, 04:53 PM

Originally posted by Class A

Why don't you wait until a model receives hardware-based video stabilisation (either from the get go or through a firmware update)?

Or get a K-5 II?

I have two windows of opportunity with family members travelling to the UK, who could potentially bring a new body back for me.
That's the major driver.

Must say that I've been looking at mirrorless alternatives also, given Pentax aren't moving in the direction I want for video. I only have a few lenses that include mechanical aperture rings now, so that rules them out for manual focus use on a mirrorless, unless the adapters have that option built in. I don't want to mix systems further than a new body and maybe one dedicated 35mm lens.

Will see how we go. Plan to list the K-30 soon as we don't need two bodies at the moment. Measured the shutter count at 19,740 I think it was, and was impressed with the build quality as I checked it over. Having had the aperture issue professionally replaced under warranty, it's a solid bit of kit.

04-07-2017, 11:47 PM	#13040
pixelsaurus Site Supporter Join Date: Jul 2007 Location: Te Kuiti, NZ Photos: Gallery \| Albums Posts: 986	Originally posted by GUB So In astro stacking the underexposures are added up to increase exposure. ? Yes. The shorter exposures also assist in controlling noise. Most astros seem to shoot in roughly 3 minute exposures for faint objects. Longer exposures as well as burning out the stars, also generates noise. There is a law of diminishing returns for exposure and it seems beyond 3 minutes offers little benefit. For the brighter DSO's (Deep Sky Objects such as the Great Nebula in Orion), they include exposures down to 5 secs or so in the stack. Some astros such as Rolf Wahl Olsen and Sara Wager, to mention two, often stack images where the total exposure runs to over 100 hours. Of course they don't use DSLR's but dedicated monochrome CCD cameras and narrow band filters.This is a whole different type of photography. Originally posted by GUB This doesn't happen in normal focus stacking does it? I would hazard a guess and say things like Helicon Focus and Zerene Stacker use different criteria to stack. Maybe something to do with contrast. Last edited by pixelsaurus; 04-07-2017 at 11:50 PM. Reason: speling n gramma

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04-07-2017, 12:23 AM	#13036
pixelsaurus Site Supporter Join Date: Jul 2007 Location: Te Kuiti, NZ Photos: Gallery \| Albums Posts: 986	Originally posted by GUB So you mean Low exposures rather than shutter time and saturation as in heading towards overexposure? The problem with astrophotography is that the night sky has a huge dynamic range, probably in the range of 1:squillions. No film or digi sensor can adequately cover it. Sometimes those digi astrophotog fellas will shoot some short exposures (records star colours but with little background detail) to stack along with their longer exposure frames (overexposed bright stars but plenty of background detail). It helps to preserve the colour in the stars. Rolf does a good job in that respect. Nebulae - rolfolsenastrophotography Jerry has words to say as well: Recording and Enhancing Star Colors You can buy actions for PS to pull out star colour as well. Enterprise Astronomy & Photography \| Annie's Astro Actions Astronomy Tools Actions Set by ProDigital Software

04-07-2017, 04:26 AM	#13037
GUB Loyal Site Supporter Join Date: Aug 2012 Location: Wanganui Photos: Gallery \| Albums Posts: 5,760	Originally posted by pixelsaurus The problem with astrophotography is that the night sky has a huge dynamic range, probably in the range of 1:squillions. No film or digi sensor can adequately cover it Yeah and then comes the trade off -do you have a billion stars in your shot and suffer the brighter ones burning themselves up to an unnatural size or do you put up with less stars in your image coz the little ones havent triggered the sensor

04-07-2017, 03:44 PM	#13038
Kiwi645hauler Veteran Member Join Date: Mar 2016 Location: Dunedin Posts: 394	Originally posted by GUB So you mean Low exposures rather than shutter time and saturation as in heading towards overexposure? I have discovered I am colour insensitve in the red cyan line like a lot of older men. Funnily enough it has only proven to be a problem doing black and white printing.! What he means is use lots of short exposures ie 10x 15s exposures rather than 4x 60s exposures. the shorter exposure times keep the star colors correct and make it easier to stack images as the stars havent started to really trail

04-07-2017, 06:24 PM	#13039
GUB Loyal Site Supporter Join Date: Aug 2012 Location: Wanganui Photos: Gallery \| Albums Posts: 5,760	Originally posted by Kiwi110Auto What he means is use lots of short exposures ie 10x 15s exposures rather than 4x 60s exposures. the shorter exposure times keep the star colors correct and make it easier to stack images as the stars havent started to really trail So In astro stacking the underexposures are added up to increase exposure. ? This doesn't happen in normal focus stacking does it?

04-08-2017, 12:06 AM	#13041
NZ_Ross Kiwi Pentaxian Join Date: Mar 2012 Location: Timaru Photos: Gallery \| Albums Posts: 4,225	Originally posted by richandfleur What sort of things did you eventually come to change with the K-3 over your previous behaviours with the K-5? Hi Richard, I think there were a couple of main observations - The K-3 has no AA filter and the 24MP sensor, compared with the 16MP AA'ed sensor of the K-5. The first thing I had to get used to is a 24MP no AA filter sensor output does not look good if you slightly miss focus or get anything in that area wrong. Some of my best lenses - the Zeiss and Voigtlander lenses are manual focus, so slightly missed focus is a distinct possibility. So I learnt to take more care - more shot discipline should I say. When it is spot on the images are fantastic, when you ever so slightly get it wrong you really notice. Secondly, the RAW files from the K-3 appear 'flat' when compared with the K-5 files - I think again this is just the different sensors and RAW convertor setup. The is clearly a lot more information in the K-3 files, but it took a bit of getting used to in terms of the change, and just some slightly different post processing techniques. What I can say is that you have more post processing 'head room' with the K-3 files. Once I got used to what I could do with the files I was a lot happier. Part of this is also the ability to crop more if you want to with the K-3 files. At the heart of noticing the differences was I had got very used to the K-5, how to shoot it, how to post process and get images I was happy with. It just took a few months to get used to the K-3, that you could do things subtly different, that you could shoot a scene and then bring up a lot more info in post processing - that sort of thing. I am now very well used to the K-3 and generally very happy with the images it gives me. When I am not happy, it is me that is at fault, not the camera - I have mucked something up generally. Handheld I shoot TAv, with SR on, and AA filter simulation off. I trust this helps with your enquiry. Cheers Ross

04-08-2017, 12:52 AM	#13043
richandfleur Pentaxian Join Date: Mar 2014 Location: Palmerston North, New Zealand Photos: Albums Posts: 1,788	Thanks Ross, The K-3 deal hasn't gone through, as the seller decided he couldn't part with it. I get that, so am now back on the hunt. Interesting comments Ross, as I've been through something similar moving from the K-30 to the K-S1, which is a similar 16MP AA filter to 20MP AA filterless jump.

04-08-2017, 03:14 AM	#13044
Kiwizinho Pentaxian Join Date: Dec 2012 Location: Blenheim Photos: Gallery Posts: 1,295	I think I'm beginning to lust after a DA 50-135 2.8. I did some family portraits for some friends today, and used the FA 50 1.4 and Tamron 90 2.8 macro, and while both are great portrait lenses, changing between them was a pain. The Tamron 70-200 2.8 also looks like a good option, but is maybe not quite wide enough. The DA 50-135 seems like it was designed with portraits in mind. It will be a while till I can afford it, and there's some other stuff I'd like as well such as flash and reflector stands, and some more external flashes. At least my wife did a pretty good job as a reflector stand. The reflector itself got its first proper outing, and had to be one of my most economical photography acquisitions. I think I paid $16 for a 5 in 1 reflector on Tradme. Taking good group portraits is hard work, especially with kids involved! Even with all the proliferation of smartphones and selfies, a really good group portrait is a real challenge. I've mostly stuck to landscapes and natural history because they feel like 'safe' subjects, but portraits really push the limits in terms of having the right equipment and skills. I'm naturally a bit of an introvert, so having subjects that you need to talk into cooperating is challenge, but after seeing results that are likely beyond the limits of any smartphone, I'm going to want to do more of this.

04-08-2017, 05:40 AM	#13045
Clarkey Site Supporter Join Date: Jan 2008 Location: Brampton, ON, Canada Photos: Gallery Posts: 2,456	Originally posted by awa355 I picked up on the different engine note today. It was way up in the air (I suppose it is meant to be) I had to crop the bejeezus out of it to get any details. Not sure what animal it is. One of you lot will know. Also attended a horse event today. The pentax is not brilliant at jpegs but I'm happy with these shots. Very good - nice, clear looking shots. Blast from my past - I used to do this sort of thing.

04-08-2017, 06:19 AM	#13046
pixelsaurus Site Supporter Join Date: Jul 2007 Location: Te Kuiti, NZ Photos: Gallery \| Albums Posts: 986	Originally posted by awa355 I picked up on the different engine note today. It was way up in the air (I suppose it is meant to be) I had to crop the bejeezus out of it to get any details. Not sure what animal it is. One of you lot will know. Maybe one of these: Mitsubishi MU-2 - Wikipedia https://www.caa.govt.nz/script/air-reg-query/

04-09-2017, 07:11 AM	#13047
Class A Pentaxian Join Date: Aug 2008 Location: Wellington, New Zealand Posts: 11,251 Original Poster	Originally posted by richandfleur The K-3 deal hasn't gone through, as the seller decided he couldn't part with it. I get that, so am now back on the hunt. Why don't you wait until a model receives hardware-based video stabilisation (either from the get go or through a firmware update)? Or get a K-5 II?

04-09-2017, 12:53 PM	#13048
Transit Pentaxian Join Date: Aug 2007 Location: Whanganui NZ Photos: Gallery \| Albums Posts: 4,624	or my K-5iis 15k on the shutter...unmarked

04-09-2017, 04:34 PM	#13049
Kiwi645hauler Veteran Member Join Date: Mar 2016 Location: Dunedin Posts: 394	Woo... less than 1 week to Classic Fighters Omaka, I leave Dunedin Wednesday afternoon with an overnight stop in CHCH, then on to Blenheim Thursday. Camera bags are packed, film stocked up and ready to go.

04-09-2017, 04:53 PM	#13050
richandfleur Pentaxian Join Date: Mar 2014 Location: Palmerston North, New Zealand Photos: Albums Posts: 1,788	Originally posted by Class A Why don't you wait until a model receives hardware-based video stabilisation (either from the get go or through a firmware update)? Or get a K-5 II? I have two windows of opportunity with family members travelling to the UK, who could potentially bring a new body back for me. That's the major driver. Must say that I've been looking at mirrorless alternatives also, given Pentax aren't moving in the direction I want for video. I only have a few lenses that include mechanical aperture rings now, so that rules them out for manual focus use on a mirrorless, unless the adapters have that option built in. I don't want to mix systems further than a new body and maybe one dedicated 35mm lens. Will see how we go. Plan to list the K-30 soon as we don't need two bodies at the moment. Measured the shutter count at 19,740 I think it was, and was impressed with the build quality as I checked it over. Having had the aperture issue professionally replaced under warranty, it's a solid bit of kit.