[TDvN57]

Would appreciate some input if someone has used the 600mm A star lens on the 645z body. Any opinion or suggestions would be welcome. I am considering to buy one to replace my very heavy 600mm 67 lens.

[Adam]

Have you seen the user reviews?
SMC Pentax-A* 645 600mm F5.6 ED [IF] Reviews - 645 Telephoto Primes - Pentax Lens Reviews & Lens Database

[TDvN57]

Have you seen the user reviews?
SMC Pentax-A* 645 600mm F5.6 ED [IF] Reviews - 645 Telephoto Primes - Pentax Lens Reviews & Lens Database

Yes thanks, I saw those were done a while ago. I was hoping there is someone actively using the lens on a 645z that can give current information.

[Thomas]

I wrote one of the reviews and my thoughts remain the same. The lens is even better with a 645Z since the high ISO capabilities allow higher shutter speeds. Recent example attached.

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[bobbotron]

I wrote one of the reviews and my thoughts remain the same. The lens is even better with a 645Z since the high ISO capabilities allow higher shutter speeds. Recent example attached.

Hey Thomas, I'm very curious. At some point could you take some photos near minimum focal distance with this lens and the 645Z? This is a pretty neat lens, I'm curious to see what the output is like, will likely never own one myself.

[TDvN57]

I wrote one of the reviews and my thoughts remain the same. The lens is even better with a 645Z since the high ISO capabilities allow higher shutter speeds. Recent example attached.

Thomas, much appreciated. I have a few questions:

1. How much of a problem is CA, especially towards the edges.

2. I am thinking of combining it with the 1.4x converter. Any thoughts on this?
I also have a 2x converter, but are not impressed with the results on any of my lenses.

3. At present I use my 400mm lens with the 1.4x.converter to get me to 600, but at the expense of light. CA is not much of an issue in this configuration.

4. I would be using it mostly as handheld, which is a problem for a long lens, I know, any thoughts or advice on this?

[Thomas]

Hey Thomas, I'm very curious. At some point could you take some photos near minimum focal distance with this lens and the 645Z? This is a pretty neat lens, I'm curious to see what the output is like, will likely never own one myself.

Below is about close focus limit. Flowers about 3 in/8cm in diameter; not sure of the distance. Wide open BTW

---------- Post added 02-07-2017 at 03:46 PM ----------

Thomas, much appreciated. I have a few questions:

1. How much of a problem is CA, especially towards the edges.

2. I am thinking of combining it with the 1.4x converter. Any thoughts on this?
I also have a 2x converter, but are not impressed with the results on any of my lenses.

3. At present I use my 400mm lens with the 1.4x.converter to get me to 600, but at the expense of light. CA is not much of an issue in this configuration.
can get the most from th
4. I would be using it mostly as handheld, which is a problem for a long lens, I know, any thoughts or advice on this?

Almost no CA anywhere; the lens is highly corrected with 12 elements.
Works well with the 1.4x; sold my 2x.
I don't use this handheld very often and even then rest the barrel on something. I use the 400mm handheld frequently, but not the 600. Keep in mind this is a MF lens, so the hand needed to turn the focus ring also must support the lens barrel. My experience is that is very difficult to achieve the quality this lens is capable of using it handheld.
Also, shutter shake is a real issue at slower shutter speeds.

---------- Post added 02-07-2017 at 03:55 PM ----------

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Last edited by Thomas; 02-07-2017 at 11:00 AM.

[bobbotron]

Thanks for indulging my curiosity! That is very nice.

Below is about close focus limit. Flowers about 3 in/8cm in diameter; not sure of the distance. Wide open BTW

---------- Post added 02-07-2017 at 03:46 PM ----------



Almost no CA anywhere; the lens is highly corrected with 12 elements.
Works well with the 1.4x; sold my 2x.
I don't use this handheld very often and even then rest the barrel on something. I use the 400mm handheld frequently, but not the 600. Keep in mind this is a MF lens, so the hand needed to turn the focus ring also must support the lens barrel. My experience is that is very difficult to achieve the quality this lens is capable of using it handheld.
Also, shutter shake is a real issue at slower shutter speeds.

---------- Post added 02-07-2017 at 03:55 PM ----------



Almost no CA anywhere; with 12 elements it's a very well corrected lens.
1.4x works well; I sold my 2x.
I rarely use it handheld and when I do, I try to rest the barrel on something; it's an awkward lens to hold and focus. I use the 400mm handheld frequently, but not the 600.

[TDvN57]

Below is about close focus limit. Flowers about 3 in/8cm in diameter; not sure of the distance. Wide open BTW

---------- Post added 02-07-2017 at 03:46 PM ----------



Almost no CA anywhere; the lens is highly corrected with 12 elements.
Works well with the 1.4x; sold my 2x.
I don't use this handheld very often and even then rest the barrel on something. I use the 400mm handheld frequently, but not the 600. Keep in mind this is a MF lens, so the hand needed to turn the focus ring also must support the lens barrel. My experience is that is very difficult to achieve the quality this lens is capable of using it handheld.
Also, shutter shake is a real issue at slower shutter speeds.

---------- Post added 02-07-2017 at 03:55 PM ----------

Thank you, much appreciated.

[672]

just to be clear, your 67 400mm edif lens plus 1.4 converter is only one pound heavier than the 645 600mm.

---------- Post added 02-09-17 at 12:45 AM ----------

i use the 67 400mm edif lens myself. sometimes with converter. its and amazing combo.

you mention that you would put a converter on the 645 600. in that case don't rule out the 67 800mm.......

[TDvN57]

just to be clear, your 67 400mm edif lens plus 1.4 converter is only one pound heavier than the 645 600mm.

---------- Post added 02-09-17 at 12:45 AM ----------

i use the 67 400mm edif lens myself. sometimes with converter. its and amazing combo.

you mention that you would put a converter on the 645 600. in that case don't rule out the 67 800mm.......

I currently have the 67 600mm with converter, but it weighs 6.5kg, excluding the camera. I find handheld impossible. Looking to switch to the 645 600mm instead.

[wilco23]

Just curious, A-star 600mm compare to Mamiya 500/4.5 apo, which one would have better optical quality? I would like to see 100% crop from this lens with 645z.

[TDvN57]

Thomas, much appreciated. I have a few questions:

1. How much of a problem is CA, especially towards the edges.

2. I am thinking of combining it with the 1.4x converter. Any thoughts on this?
I also have a 2x converter, but are not impressed with the results on any of my lenses.

3. At present I use my 400mm lens with the 1.4x.converter to get me to 600, but at the expense of light. CA is not much of an issue in this configuration.

4. I would be using it mostly as handheld, which is a problem for a long lens, I know, any thoughts or advice on this?

One of the early test shots with my new 600mm A* lens. Taken through a dirty hotel room window on the 30th floor, across the Hong Kong harbour. At first I could not see the building by eye, it was just too dark. I guessed the focus, set a 30 second long exposure and fired away. The picture shows the original full picture and superimposed upon it is a +/- 150% crop of an apartment building, about 4km away (I measured on Google Maps the next day).

At first the results look like a bad out of focus shot, however considering that the building is 4km away, it is a 30 second exposure and through a really dirty window, I am impressed with the outcome. Ignoring the potential tripod shake and movements, at that distance the structural movement of the building I am in will contribute to the "shake" effect seen in the picture.

Now I need to learn how to work this baby and then take it out for some real pictures.

[CarlG]

Looks good. Congrats!

[desertscape]

Just curious, A-star 600mm compare to Mamiya 500/4.5 apo, which on would have better optical quality?

Both of these lenses are modern designs using low dispersion glass. They are both probably corrected for 3 colors and have very low tertiary spectrum and low spherochromatism. I have not compared the two but it is safe to say that they have similar performance.