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12-26-2015, 11:51 AM   #1
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Moving from Canon 35mm to Pentax 645Z

Hello, this is my first post and as the tittle says Im considering moving from Canon (5DIII) 35mm to Pentax 645Z.
My current lenses are all primes from Canon and Zeiss (f2/35mm, f1,4/50mm, f2,8/65mm (macro 1:1 to 5:1), f1,4/85mm and f2,8/100mm (macro 1:1).
My type of work: https://www.flickr.com/photos/136118314@N06/albums

I would like to understand with your kind help two points to start (concerning lens), please:
1. in a medium format Pentax lens a value of f2,8 is as fast as an f2,8 in my current 35mm lens? Or faster?
2. as far as I could understand the medium format DOF is a bit different (smaller) due to the bigger sensor size. Is it possible to achieve the DOF as small as of (ex.) a Canon 85mm f/1,2 with a Pentax MD lens? If so which one?

Forgive me these very basic questions but its a starting point.

FYI-Why I want to make the move?
a) Canon is a "slow company". 50 megapixels (5DsR) arent enough to upgrade if the dynamic range is not as good as the Sony sensors (Sony/Pentax/Nikon/Hasselblad/Phase 1, etc).
b) I want to work with a bigger sensor and its unique look, DR, etc.
c) All reviews about the Pentax 645Z are ***** reviews. I love the Canon ergonomics and menu navigation but I trust that the Pentax system will work very well too.
There is only one point Pentax cannot match; I think: (the unique MP-E 65mm Macro x1:1 to 5:1 lens) but moving is changing ,-) isnt it?

Thank you very much for your help.
Regards

12-26-2015, 12:11 PM   #2
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QuoteOriginally posted by Pansottin Quote
1. in a medium format Pentax lens a value of f2,8 is as fast as an f2,8 in my current 35mm lens? Or faster?
It provides a shallower depth of field on MF, but not more light.

QuoteQuote:
2. as far as I could understand the medium format DOF is a bit different (smaller) due to the bigger sensor size. Is it possible to achieve the DOF as small as of (ex.) a Canon 85mm f/1,2 with a Pentax MD lens? If so which one?
There is a depth of field calculator online. The fastest Pentax 645 lenses are f/2.8. On a 645D (doesn't show the 645Z) with the subject 10 feet away the smc FA 645 150 mm f/2.8 provides a depth of field of 0.36 feet. Your Canon combo provides 0.29 feet at f/1.2. Shallower, but does it matter to you?
12-26-2015, 12:20 PM   #3
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Thank you very much FMF .-)
More DOF but the same light for the same F-number? Correct?
Is there any technical impossibility (or maybe a production/commercial price limitation) to produce faster MF lens than f/2,8?
Thank again.
12-26-2015, 12:25 PM   #4
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QuoteOriginally posted by Pansottin Quote
1. in a medium format Pentax lens a value of f2,8 is as fast as an f2,8 in my current 35mm lens? Or faster?
The small format nicknamed "FF" in digital era is a crop format versus the 645z MF format.
The crop factor is x1.3 just as the crop factor between APSC and 35mm is x1.6 in Canon world.

QuoteOriginally posted by Pansottin Quote
2. as far as I could understand the medium format DOF is a bit different (smaller) due to the bigger sensor size. Is it possible to achieve the DOF as small as of (ex.) a Canon 85mm f/1,2 with a Pentax MD lens? If so which one?
The fastest lens you can use on the 645z is the Hasselblad 110mm F2 lens (see here: The Pentax 645z a wedding photographers medium format dream | Wollongong, Illawarra, Southern Highlands, Sydney & Destination wedding photography)
Obviously 110/2 equals a crop lens (35mm lens) with 85mm F1.5.
So, no, the extremely fast Canon lenses are not a MF domain, you can just reach Nikon level.

12-26-2015, 12:32 PM   #5
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QuoteOriginally posted by beholder3 Quote
The small format nicknamed "FF" in digital era is a crop format versus the 645z MF format.
The crop factor is x1.3 just as the crop factor between APSC and 35mm is x1.6 in Canon world.



The fastest lens you can use on the 645z is the Hasselblad 110mm F2 lens (see here: The Pentax 645z a wedding photographers medium format dream | Wollongong, Illawarra, Southern Highlands, Sydney & Destination wedding photography)
Obviously 110/2 equals a crop lens (35mm lens) with 85mm F1.5.
So, no, the extremely fast Canon lenses are not a MF domain, you can just reach Nikon level.
Thank you B3.
Even if its not as fast as the Canon glass, in term of DOF aspect/aesthetics with the Pentax MF, "the look" is quite unique I guess .-)
12-26-2015, 01:41 PM   #6
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QuoteOriginally posted by Pansottin Quote
Hello, this is my first post and as the tittle says Im considering moving from Canon (5DIII) 35mm to Pentax 645Z.
My current lenses are all primes from Canon and Zeiss (f2/35mm, f1,4/50mm, f2,8/65mm (macro 1:1 to 5:1), f1,4/85mm and f2,8/100mm (macro 1:1).
My type of work: https://www.flickr.com/photos/136118314@N06/albums

I would like to understand with your kind help two points to start (concerning lens), please:
1. in a medium format Pentax lens a value of f2,8 is as fast as an f2,8 in my current 35mm lens? Or faster?
2. as far as I could understand the medium format DOF is a bit different (smaller) due to the bigger sensor size. Is it possible to achieve the DOF as small as of (ex.) a Canon 85mm f/1,2 with a Pentax MD lens? If so which one?

Forgive me these very basic questions but its a starting point.

FYI-Why I want to make the move?
a) Canon is a "slow company". 50 megapixels (5DsR) arent enough to upgrade if the dynamic range is not as good as the Sony sensors (Sony/Pentax/Nikon/Hasselblad/Phase 1, etc).
b) I want to work with a bigger sensor and its unique look, DR, etc.
c) All reviews about the Pentax 645Z are ***** reviews. I love the Canon ergonomics and menu navigation but I trust that the Pentax system will work very well too.
There is only one point Pentax cannot match; I think: (the unique MP-E 65mm Macro x1:1 to 5:1 lens) but moving is changing ,-) isnt it?

Thank you very much for your help.
Regards
The 645Z DR is much better than Canon offerings but the major advantage is also bigger files sizes for large prints. I do not own the 645Z but do own the MF 120 f4 macro lens. I have used the lens on my Canon 6D and now on my Pentax K3. It is a very sharp lens even at f4. The only way to know for sure is to try the 645Z and the 120 macro or the 90 macro combo. Perhaps rent it for a few days and check it out.

You pics and your style are very unique. Do you make large prints for final presentation?
12-26-2015, 01:41 PM   #7
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For Pentax's current Digital Medium Format lenses, you take the focal length and times it by 0.79 and you'll get the 35mm equivalent (or near equiv.)
55mm x 0.79 = 43.45 (35mm Equiv. (or a 50mm lens on a FF camera))
12-26-2015, 02:04 PM   #8
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QuoteOriginally posted by btnapa Quote
The 645Z DR is much better than Canon offerings but the major advantage is also bigger files sizes for large prints. I do not own the 645Z but do own the MF 120 f4 macro lens. I have used the lens on my Canon 6D and now on my Pentax K3. It is a very sharp lens even at f4. The only way to know for sure is to try the 645Z and the 120 macro or the 90 macro combo. Perhaps rent it for a few days and check it out.

You pics and your style are very unique. Do you make large prints for final presentation?
Hi btnapa, thank you also for your opinion.
The DR is definitely better (trusting in what I read). Renting is a good suggestion, but not easy for me.
DR is very important of me but also bigger print because I print in digital but also in (Pt/Pd) Platinum/Palladium (the bigger the negative the bigger the print). With my current Canon I can only produce 25x25cm negatives with the appropriate ppi.
So bigger files sizes for contact large prints is a goal.
For now Ive just 25x25/50x50cm digital prints for sale:
Fine Art Prints_Music
Fine Art Prints_Italia Nostra
Im preparing (Pt/Pd) editions, but for now just as big as 25x25cm. I like a lot the square format.

Thanks for your words .-)

---------- Post added 12-26-15 at 02:04 PM ----------

QuoteOriginally posted by disconnekt Quote
For Pentax's current Digital Medium Format lenses, you take the focal length and times it by 0.79 and you'll get the 35mm equivalent (or near equiv.)
55mm x 0.79 = 43.45 (35mm Equiv. (or a 50mm lens on a FF camera))
Thank you too Dkt .-) for the help.


Last edited by Pansottin; 12-26-2015 at 02:19 PM.
12-26-2015, 02:22 PM   #9
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QuoteOriginally posted by Pansottin Quote
Hi btnapa, thank you also for your opinion.
The DR is definitely better (trusting in what I read). Renting is a good suggestion, but not easy for me.
DR is very important of me but also bigger print because I print in digital but also in (Pt/Pd) Platinum/Palladium (the bigger the negative the bigger the print). With my current Canon I can only produce 25x25cm negatives with the appropriate ppi.
So bigger files sizes for contact large prints is a goal.
For now Ive just 25x25/50x50cm digital prints for sale:
Fine Art Prints_Music
Fine Art Prints_Italia Nostra
Im preparing (Pt/Pd) editions, but for now just as big as 25x25cm. I like a lot the square format.

Thanks for your words .-)

---------- Post added 12-26-15 at 02:04 PM ----------


Thank you too Dkt .-) for the help.
Hi Pansottin,

Just comparing my Canon 6D with my K3, I can tell you that the Pentax DR is much better. Details recovered from the shadows in my K3 have less artifacts than my 6D. I have read the reviews and people are talking about 4 to 5 stop shadow recovery from the 645Z. That is incredible DR. I am contemplating a 645Z too as I print large as well. So far I have used pano techniques to achieve large print sizes. I will wait for the Pentax FF to show up and then make my final decision. If I move to the 645Z, my prints size expectations are in the 42"x56" range and large from a single file.

Your 50x50cm requirement is a piece of cake for the 645Z. You can get much larger prints perhaps 100cmx100cm or larger and see little artifacts and plenty of detail.
12-26-2015, 02:29 PM   #10
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QuoteOriginally posted by Pansottin Quote
I love the Canon ergonomics and menu navigation
Canon copied the ergonomics of Pentax cameras years ago. So moving to the Pentax 645Z is very easy for a Canon user. You can use 90% of features without picking up the manual. Menu navigation is different.

---------- Post added 12-27-15 at 08:34 AM ----------

QuoteOriginally posted by Pansottin Quote
There is only one point Pentax cannot match; I think: (the unique MP-E 65mm Macro x1:1 to 5:1 lens) but moving is changing ,-) isnt it?
Correct, but they have a superb 90mm Macro for the 645Z.
12-26-2015, 04:29 PM   #11
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QuoteOriginally posted by btnapa Quote
Hi Pansottin,

Just comparing my Canon 6D with my K3, I can tell you that the Pentax DR is much better. Details recovered from the shadows in my K3 have less artifacts than my 6D. I have read the reviews and people are talking about 4 to 5 stop shadow recovery from the 645Z. That is incredible DR. I am contemplating a 645Z too as I print large as well. So far I have used pano techniques to achieve large print sizes. I will wait for the Pentax FF to show up and then make my final decision. If I move to the 645Z, my prints size expectations are in the 42"x56" range and large from a single file.

Your 50x50cm requirement is a piece of cake for the 645Z. You can get much larger prints perhaps 100cmx100cm or larger and see little artifacts and plenty of detail.
Digital prints can always be bigger than "the sensor", even without interpolation.
Historical contact prints must respect certain limits. But with a 50 megapixels sensor plus a good DR one can print large gorgeous Pt/Pd prints. Also because a huge DR favors a good B&W conversion.
Apart from that aspect, I expect to achieve "a look" that is beyond 35mm .-)
Am I wrong?

---------- Post added 12-26-15 at 04:30 PM ----------

QuoteOriginally posted by TheDocAUS Quote
Canon copied the ergonomics of Pentax cameras years ago. So moving to the Pentax 645Z is very easy for a Canon user. You can use 90% of features without picking up the manual. Menu navigation is different.

---------- Post added 12-27-15 at 08:34 AM ----------



Correct, but they have a superb 90mm Macro for the 645Z.
"Canon copied the ergonomics of Pentax cameras years ago

Read more at: https://www.pentaxforums.com/forums/48-pentax-medium-format/310494-moving-canon-35mm-pentax-645z.html#ixzz3vTMpbqZr"

True?

---------- Post added 12-26-15 at 04:35 PM ----------

QuoteOriginally posted by TheDocAUS Quote
Canon copied the ergonomics of Pentax cameras years ago. So moving to the Pentax 645Z is very easy for a Canon user. You can use 90% of features without picking up the manual. Menu navigation is different.

---------- Post added 12-27-15 at 08:34 AM ----------



Correct, but they have a superb 90mm Macro for the 645Z.
Pentax 90mm f/2.8 D FA 645 Macro ED AW SR Lens 22210 B&H Photo

But far more expensive than my current Canon macro lens ,-(
Is there an older alternative?
Im not a huge fan of "the most sharper glass in the universe". I like some "flaws, error and character". Work with that. Like if "glass is weather" and has a mood .-)
12-26-2015, 04:41 PM   #12
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QuoteOriginally posted by Pansottin Quote
But far more expensive than my current Canon macro lens ,-(
Look here and here for 645 lens. Much cheaper macro here.
12-26-2015, 04:45 PM   #13
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QuoteQuote:
But far more expensive than my current Canon macro lens ,-(
Is there an older alternative?
The older 120mm f/4 macro is dirt cheap (look on ebay) 2nd hand.

Optically it makes a mockery of the canon 100mm macro. Not sure about the 65mm, thats a pretty specialised lens.

---------- Post added 12-26-15 at 04:52 PM ----------

In general from your earlier comments - yes the canon 85mm can get lower DoF - whether it's usable at 1.2 is a different story.

As much as the 645z is a beast at print quality, from looking at your site your photos really don't look that demanding resolution wise. I can't imagine why you think the canon will only do 25x25cm.
12-26-2015, 05:11 PM   #14
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QuoteOriginally posted by TheDocAUS Quote
Look here and here for 645 lens. Much cheaper macro here.
Will check; thank you.

---------- Post added 12-26-15 at 05:13 PM ----------

QuoteOriginally posted by gavincato Quote
The older 120mm f/4 macro is dirt cheap (look on ebay) 2nd hand.

Optically it makes a mockery of the canon 100mm macro. Not sure about the 65mm, thats a pretty specialised lens.

---------- Post added 12-26-15 at 04:52 PM ----------

In general from your earlier comments - yes the canon 85mm can get lower DoF - whether it's usable at 1.2 is a different story.

As much as the 645z is a beast at print quality, from looking at your site your photos really don't look that demanding resolution wise. I can't imagine why you think the canon will only do 25x25cm.
25x25cm with 360ppi is a standard for Pt/Pd digital negatives (maybe youre not familiar with the process; sorry if Im unfair with you :-) Square crop from a 22 megapixels file.
12-27-2015, 06:02 AM   #15
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QuoteOriginally posted by gavincato Quote
The older 120mm f/4 macro is dirt cheap (look on ebay) 2nd hand.

Optically it makes a mockery of the canon 100mm macro. Not sure about the 65mm, thats a pretty specialised lens.

---------- Post added 12-26-15 at 04:52 PM ----------

In general from your earlier comments - yes the canon 85mm can get lower DoF - whether it's usable at 1.2 is a different story.

As much as the 645z is a beast at print quality, from looking at your site your photos really don't look that demanding resolution wise. I can't imagine why you think the canon will only do 25x25cm.
Did you have the chance to compare both?
My Canon 100mm macro is the "L" version.
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