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**jackinkc** · 12-02-2011, 06:32 PM

I am experiencing slow write times with my 645D. I would like to work this out with the assistance of others.

Adam · 12-02-2011, 06:55 PM - **1 Like**

Do you have a class 10 or higher card? The faster your card, the faster the camera can write.

The processor is pretty slow in general though, so you will have to get used to having to wait a little bit to see the photo after you shoot it

alunfoto · 12-03-2011, 02:03 AM

My current cards are 16GB Sandisk Extreme Pro, labeled 45 MB/s.
I don't have exact timings, but it looks like just under 4 seconds in total with these cards. The time between the shutter closing and image stored is divided 50-50 between camera processing and file saving.
How does that align with your write times, jackinkc?

best,
Jostein

alunfoto · 12-03-2011, 02:05 AM - **1 Like**

Originally posted by Adam

The processor is pretty slow in general though,

It is not "pretty slow in general". It is handling large amounts of data in particular.

Anvh · 12-04-2011, 12:37 PM - **1 Like**

From what i can tell it share almost the same hardware with the K5.
I believe the SD write speed came close to 20 to 25MB/s.

But card speed isn't that important,as far as i know an image would take this route: sensor > RAM > processing > RAM > SD.
So as long as the RAM isn't full SD speed won't limit it.

**jackinkc** · 12-05-2011, 03:43 PM

Originally posted by alunfoto

My current cards are 16GB Sandisk Extreme Pro, labeled 45 MB/s.
I don't have exact timings, but it looks like just under 4 seconds in total with these cards. The time between the shutter closing and image stored is divided 50-50 between camera processing and file saving.
How does that align with your write times, jackinkc?
best,
Jostein

I am using 32GB, 30 MB/s cards. The write time is about 15 seconds in the studio, with flash, and about 8 seconds with regular exposure. That variation makes no sense to me, but I guess 8 seconds write time is not that bad. I suppose if I went to faster cards all would be OK.

Adam suggested a class 10 card or faster; a limited online search shows class10 to be about 24 MB/s. Unless I am misreading the specs looks like Jostein's 45 and my 30 are both faster than class 10.

Maybe I should shut up and use what I have.

ACH DIGITAL · 12-05-2011, 06:14 PM

Hi guys, are using two cards or just one. Are you writing RAW + JPG or just RAW. ??

**Ed Hurst** · 12-05-2011, 06:40 PM

The 645D achieves, by comparison to more mainstream DLSRs, pretty slow write speeds to the card. This is partly due to the huge file sizes, and partly due to the fact (I believe) that the camera contains some systems/components taken from other DSLRs (which is one of the reasons that the camera is relatively cheap - for a MF DSLR). So expectations should not be too high for speeds. As long as you have a reasonably fast card, you will find that getting an even faster card makes zero difference - as the limiting factor is the camera's own write speed and not the card.

Having said that, writing to only one card (rather than both), shooting only one format (i.e. not RAW + JPG) and turning off some of the processing options (e.g. lens corrections) will speed things up somewhat. Personally I leave lens corrections on, but shoot only RAW format; I shoot to only one card, unless I am taking a vitally important picture where speed is not of the essence. That maximises speed. But it will never be a fast camera.

**jackinkc** · 12-05-2011, 07:06 PM

Originally posted by ACH DIGITAL

Hi guys, are using two cards or just one. Are you writing RAW + JPG or just RAW. ??

I carry two 32 GB cards but only shoot to #1. #2 card is only for the unlikely event that I run out of room. I only shoot in .DNG RAW format.

ACH DIGITAL · 12-05-2011, 07:11 PM

Thank you for the information. I'm in the market for one and this is what I've been checking for. In comparison to other medium format 40 mpx cameras, is it too much of a difference? Sorry to compare but just need the info..

Yamanobori · 12-05-2011, 07:42 PM

Having experienced corrupt cards, I always shoot so each RAW shot is saved to both cards--it is like a built-in RAID 1 array. If one of the cards should ever become corrupt, the other will have the image.

Write speeds are a bit of a pain, but nothing you can't deal with.

Anvh · 12-05-2011, 08:16 PM

Originally posted by Ed Hurst

Personally I leave lens corrections on, but shoot only RAW format.

Lens correction isn'r aplied to the RAW file only to the JPGs and the JPG preview inside the RAW.
So in your case you can simply leave it off without any penalty and improve the speed a bit.

**jackinkc** · 12-05-2011, 08:24 PM

Originally posted by ACH DIGITAL

Thank you for the information. I'm in the market for one and this is what I've been checking for. In comparison to other medium format 40 mpx cameras, is it too much of a difference? Sorry to compare but just need the info..

I think the 645d image quality will compare favorably with any other MF digital. I KNOW pentax lenses are as good as any.

ACH DIGITAL · 12-06-2011, 06:29 AM

Oh I know for sure (have downloaded several files) they are comparable in image quality. What I'd like to know is writing speed processing compare to lets say PO or HD..

Yamanobori · 12-06-2011, 12:09 PM

You should be able to contact a dealer to find the write times. Better yet, rent some of these cameras and try them out. It is going to be a rare individual who owns two different MFD systems--not impossible, but really not common.

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12-02-2011, 06:32 PM	#1
jackinkc Site Supporter Join Date: Dec 2011 Location: Kansas City, Missouri Posts: 118	645D write speed I am experiencing slow write times with my 645D. I would like to work this out with the assistance of others.

12-02-2011, 06:55 PM - 1 Like	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,608	Do you have a class 10 or higher card? The faster your card, the faster the camera can write. The processor is pretty slow in general though, so you will have to get used to having to wait a little bit to see the photo after you shoot it Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

12-03-2011, 02:03 AM	#3
alunfoto Forum Member Join Date: Apr 2008 Location: Norway Photos: Gallery Posts: 72	My current cards are 16GB Sandisk Extreme Pro, labeled 45 MB/s. I don't have exact timings, but it looks like just under 4 seconds in total with these cards. The time between the shutter closing and image stored is divided 50-50 between camera processing and file saving. How does that align with your write times, jackinkc? best, Jostein

12-03-2011, 02:05 AM - 1 Like	#4
alunfoto Forum Member Join Date: Apr 2008 Location: Norway Photos: Gallery Posts: 72	Originally posted by Adam The processor is pretty slow in general though, It is not "pretty slow in general". It is handling large amounts of data in particular.

12-04-2011, 12:37 PM - 1 Like	#5
Anvh Veteran Member Join Date: Sep 2011 Posts: 4,616	From what i can tell it share almost the same hardware with the K5. I believe the SD write speed came close to 20 to 25MB/s. But card speed isn't that important,as far as i know an image would take this route: sensor > RAM > processing > RAM > SD. So as long as the RAM isn't full SD speed won't limit it.

12-05-2011, 03:43 PM	#6
jackinkc Site Supporter Join Date: Dec 2011 Location: Kansas City, Missouri Posts: 118 Original Poster	Originally posted by alunfoto My current cards are 16GB Sandisk Extreme Pro, labeled 45 MB/s. I don't have exact timings, but it looks like just under 4 seconds in total with these cards. The time between the shutter closing and image stored is divided 50-50 between camera processing and file saving. How does that align with your write times, jackinkc? best, Jostein I am using 32GB, 30 MB/s cards. The write time is about 15 seconds in the studio, with flash, and about 8 seconds with regular exposure. That variation makes no sense to me, but I guess 8 seconds write time is not that bad. I suppose if I went to faster cards all would be OK. Adam suggested a class 10 card or faster; a limited online search shows class10 to be about 24 MB/s. Unless I am misreading the specs looks like Jostein's 45 and my 30 are both faster than class 10. Maybe I should shut up and use what I have.

12-05-2011, 06:14 PM	#7
ACH DIGITAL New Member Join Date: Dec 2011 Posts: 11	Hi guys, are using two cards or just one. Are you writing RAW + JPG or just RAW. ??

12-05-2011, 06:40 PM	#8
Ed Hurst Site Supporter Join Date: May 2010 Location: Sydney Posts: 1,657	The 645D achieves, by comparison to more mainstream DLSRs, pretty slow write speeds to the card. This is partly due to the huge file sizes, and partly due to the fact (I believe) that the camera contains some systems/components taken from other DSLRs (which is one of the reasons that the camera is relatively cheap - for a MF DSLR). So expectations should not be too high for speeds. As long as you have a reasonably fast card, you will find that getting an even faster card makes zero difference - as the limiting factor is the camera's own write speed and not the card. Having said that, writing to only one card (rather than both), shooting only one format (i.e. not RAW + JPG) and turning off some of the processing options (e.g. lens corrections) will speed things up somewhat. Personally I leave lens corrections on, but shoot only RAW format; I shoot to only one card, unless I am taking a vitally important picture where speed is not of the essence. That maximises speed. But it will never be a fast camera.

12-05-2011, 07:06 PM	#9
jackinkc Site Supporter Join Date: Dec 2011 Location: Kansas City, Missouri Posts: 118 Original Poster	Originally posted by ACH DIGITAL Hi guys, are using two cards or just one. Are you writing RAW + JPG or just RAW. ?? I carry two 32 GB cards but only shoot to #1. #2 card is only for the unlikely event that I run out of room. I only shoot in .DNG RAW format.

12-05-2011, 07:11 PM	#10
ACH DIGITAL New Member Join Date: Dec 2011 Posts: 11	Thank you for the information. I'm in the market for one and this is what I've been checking for. In comparison to other medium format 40 mpx cameras, is it too much of a difference? Sorry to compare but just need the info..

12-05-2011, 07:42 PM	#11
Yamanobori Veteran Member Join Date: Feb 2011 Photos: Gallery Posts: 573	Having experienced corrupt cards, I always shoot so each RAW shot is saved to both cards--it is like a built-in RAID 1 array. If one of the cards should ever become corrupt, the other will have the image. Write speeds are a bit of a pain, but nothing you can't deal with.

12-05-2011, 08:16 PM	#12
Anvh Veteran Member Join Date: Sep 2011 Posts: 4,616	Originally posted by Ed Hurst Personally I leave lens corrections on, but shoot only RAW format. Lens correction isn'r aplied to the RAW file only to the JPGs and the JPG preview inside the RAW. So in your case you can simply leave it off without any penalty and improve the speed a bit.

12-05-2011, 08:24 PM	#13
jackinkc Site Supporter Join Date: Dec 2011 Location: Kansas City, Missouri Posts: 118 Original Poster	Originally posted by ACH DIGITAL Thank you for the information. I'm in the market for one and this is what I've been checking for. In comparison to other medium format 40 mpx cameras, is it too much of a difference? Sorry to compare but just need the info.. I think the 645d image quality will compare favorably with any other MF digital. I KNOW pentax lenses are as good as any.

12-06-2011, 06:29 AM	#14
ACH DIGITAL New Member Join Date: Dec 2011 Posts: 11	Oh I know for sure (have downloaded several files) they are comparable in image quality. What I'd like to know is writing speed processing compare to lets say PO or HD..

12-06-2011, 12:09 PM	#15
Yamanobori Veteran Member Join Date: Feb 2011 Photos: Gallery Posts: 573	You should be able to contact a dealer to find the write times. Better yet, rent some of these cameras and try them out. It is going to be a rare individual who owns two different MFD systems--not impossible, but really not common.

645D write speed

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